Epidemiology,Treatment Patterns,Comorbidities,and Concomitant Medication in Patients with ADHD in Sweden: A Registry-Based Study (2018

Abstract

Objective:

To evaluate treatment patterns for ADHD in Sweden.

Method:

Observational retrospective study of patients with ADHD from the Swedish National Patient Register and Prescribed Drug Register, 2018 to 2021. Cross-sectional analyses included incidence, prevalence, and psychiatric comorbidities. Longitudinal analyses (newly diagnosed patients) included medication, treatment lines, duration, time-to-treatment initiation, and switching.

Results:

Of 243,790 patients, 84.5% received an ADHD medication. Psychiatric comorbidities were common, particularly autism among children, and depression in adults. Most frequent first-/second-line treatments were methylphenidate (MPH; 81.6%) and lisdexamfetamine dimesylate (LDX; 46.0%), respectively. In the second-line, LDX was most frequently prescribed (46.0%), followed by MPH (34.9%), then atomoxetine (7.7%). Median treatment duration was longest for LDX (10.4 months), followed by amphetamine (9.1 months).

Conclusion:

This nationwide registry study provides real-life insights into the current epidemiology of ADHD and the changing treatment landscape for patients in Sweden.

Keywords

ADHD prevalence psychiatric comorbidity Sweden treatment

Introduction

ADHD is one of the most common neurodevelopmental disorders of childhood (Raman et al., 2018; Wolraich et al., 2019), affecting around 5% to 7% of children/adolescents and 2% to 3% of adults worldwide (Elliott et al., 2020; Faraone et al., 2021; Polanczyk et al., 2014; Polyzoi et al., 2018; Thomas et al., 2015). Reports from several countries suggest that the prevalence of ADHD is increasing in children and adults (Polyzoi et al., 2018), accompanied by an increased use of ADHD medication (Giacobini et al., 2018; Raman et al., 2018); however, some studies suggest that the increase in ADHD patient numbers may instead reflect improved diagnosis (Rydell et al., 2018; Song et al., 2019).

Sweden has a decentralized healthcare system that is managed either by the regions, the local authority, or municipality, and universal health coverage is provided for all residents (European Observatory on Health Systems and Policies, 2021; The National Board of Health and Welfare, 2018). Healthcare costs are mostly paid for by regional and municipal taxes, thus patients are only required to pay a small proportion of medical fees (Swedish Institute, 2022). In Sweden, ADHD is diagnosed by psychiatrists and pediatricians in specialized secondary care units. Patients who demonstrate signs and symptoms of ADHD undergo a neuropsychiatric investigation before their diagnosis is confirmed.

The annual prevalence of diagnosed ADHD in Sweden increased from 1.1 to 4.8 per 1,000 persons from 2006 to 2011 (Giacobini et al., 2018), and the annual incidence increased from 0.4 to 0.9 per 1,000 persons from 2007 to 2011 (Polyzoi et al., 2018). In approximately 60% of children with ADHD, self-reported symptoms persist into adulthood (Sibley et al., 2017), conferring a significant burden on both society and the individual. ADHD impacts negatively on employment, financial security, education, emotional well-being, social relationships, quality of life, and healthcare utilization (e.g., from increased risk of injury or smoking) (Ahnemark et al., 2018; Kooij et al., 2019; Polyzoi et al., 2018).

Additionally, recent studies have shown that around 50% of adults with ADHD have a psychiatric comorbidity, of which anxiety, depression, and substance use disorder are the most common (Ahnemark et al., 2018; Polyzoi et al., 2018). A Danish cohort study involving 2.9 million individuals (aged 10 years and upwards), found a five-fold higher rate of suicide attempts and a three-fold higher rate of death in individuals with ADHD versus those without; suicidal behavior increased substantially among those with ADHD and additional psychiatric comorbidities versus patients with ADHD only (Fitzgerald et al., 2019). Consequently, many patients also receive psychotropic medication, in addition to their ADHD medication (Polyzoi et al., 2018); this contributes to a substantial overall treatment burden.

In Swedish studies, conducted between 2006 and 2011, most patients diagnosed with ADHD received at least one pharmacologic treatment; methylphenidate (MPH, a psychostimulant) formulations were the most commonly prescribed medication for first- and second-line use (Giacobini et al., 2018; Polyzoi et al., 2018). The predominance of MPH is consistent with the Swedish guidelines and with prescribing in other European countries between 2005 and 2012 (Bachmann et al., 2017). The availability of new drugs in Sweden and other parts of Europe, however, has changed the treatment landscape for ADHD. Lisdexamfetamine dimesylate (LDX) is a long-acting pro-drug that was approved in Europe in 2013 for children/adolescents with ADHD after a clinically inadequate response to MPH and later also approved for use in adults. LDX is recommended as a second-line treatment in Sweden for children/adolescents and adults (Swedish Medical Products Agency, 2016). Dexamphetamine (DEX) was approved in 2015 for the treatment of ADHD in children/adolescents (6–17 years) for whom MPH treatment had failed (Electronic Medicines Compendium, 2020). Amphetamine (AMP) has been used in Sweden as a last treatment option since 2006 on a named-patient basis (Polyzoi et al., 2018). Atomoxetine (ATX; a non-stimulant selective noradrenaline re-uptake inhibitor) was approved in Europe in 2004 for children/adolescents, and in 2013 for adults with ADHD (Electronic Medicines Compendium, 2021). The non-stimulant agent, guanfacine (GXR, a centrally acting alpha_2A-adrenergic receptor agonist) became available in 2015 in a once-daily, extended-release formulation. GXR was approved for use in children/adolescents with ADHD for whom stimulants are either not suitable/not tolerated or ineffective (Electronic Medicines Compendium, 2023).

Consequently, there is a need to re-examine treatment options for the ADHD population, in order to understand any emerging trends that may reflect the availability and use of new medications. Ongoing evaluation of treatment patterns, both in children/adolescents and adults with ADHD, may help to inform clinical decision making and patient management.

The objectives of our study were to evaluate the epidemiology, treatment patterns, concomitant medications, and comorbidities for Swedish patients already diagnosed with ADHD between 2018 and 2021, as well as for those newly diagnosed.

Methods

Data Sources

This study used secondary data obtained from the Swedish National Patient Register (NPR) and the Prescribed Drug Register (PDR), between 2018 and 2021, for people with a registered diagnosis of ADHD. Both databases are part of the National Board of Health and Welfare (2018), Stockholm, Sweden. The NPR provides information on specialist inpatient and outpatient care, including patient characteristics (sex, age), date of visit, diagnoses, comorbidities, primary discharge diagnosis, and secondary diagnoses provided by the specialist care physician, in accordance with the World Health Organization International Statistical Classification of Diseases and Related Health Problems 10th revision (ICD-10) (WHO, 2010). By contrast, the PDR provides information on all medicines prescribed in Sweden since 2005, including those prescribed by general practitioners (Wallerstedt et al., 2016). Data were derived by linking these two national population-based registers using a unique anonymized number for each patient. Study approval was granted by the Swedish Ethical Review Agency. Patient informed consent was not sought in this retrospective study as data were de-identified; this was considered ethically acceptable by the review agency.

Study Design

This observational retrospective study included cross-sectional and longitudinal analyses, comprising different patient cohorts. Cohort A included all diagnosed patients identified from the NPR using WHO ICD-10 codes for ADHD (F90 and F98.8) between January 1, 2018, and December 31, 2020, and/or identified from the PDR as having had an ADHD prescription (Anatomical Therapeutic Chemical [ATC] codes: N06BA01, N06BA02, N06BA04, N06BA09, N06BA12, and C02AC02) between January 1, 2018, and August 31, 2021. Cohort A data were used for cross-sectional analyses to report prevalence, psychiatric comorbidities, and concomitant medications. A subgroup of Cohort A included all patients with an ADHD prescription in the PDR from January 1, 2018, until August 31, 2021 (Cohort A1); Cohort A1 data were used for cross-sectional analyses to report ADHD medications, treatment lines, treatment duration, and dosing pattern. A patient could be included in Cohort A more than once across different years. Cohort B included only newly diagnosed patients identified from the NPR using ICD-10 codes for ADHD and having their first diagnosis between January 1, 2018, and December 31, 2020, and/or were identified from the PDR as having their first ADHD prescription in the same time period. Cohort B data were used for longitudinal analyses and provided an evaluation of ADHD incidence. A subgroup of Cohort B included all patients newly diagnosed with ADHD (between January 1, 2018, and December 31, 2020) and receiving an ADHD prescription between January 1, 2018, and August 31, 2021 (Cohort B1). Cohort B1 data were used to evaluate time-to-initiation of treatment and time-to-switch, for up to 1 year after a patient’s diagnosis. All patients were followed for a maximum of 4 years after the index date of their diagnosis.

Epidemiology

Yearly prevalence and incidence (2018–2020) in Sweden were calculated, stratified by sex and age group, and expressed as a percentage. Incidence was calculated by dividing the number of newly diagnosed patients with population statistics for Sweden per year and region. Prevalence was calculated by dividing the total number of patients with population statistics for Sweden per year and region; total statistics were taken from Statistics Sweden (2021).

Treatment Patterns

Using data from individual dispensations, ADHD treatment lines and duration were evaluated and described by frequency (number/percentage of patients per regimen), as well as time-to-initiation and time-to-switching. Time-to-treatment initiation was defined as the time between diagnosis and the first dispensing of an ADHD medication (i.e., first-line treatment). Length of treatment was identified from the first date in the PDR that a prescribed ADHD treatment (DEX, AMP, ATX, GXR, LDX, or MPH) was dispensed, to supply end. If ≥90 days elapsed between the end of supply and next dispensation, this was considered a treatment discontinuation; gaps <90 days were considered as grace periods. Combination treatment was defined as dispensing of a new ADHD medication added to the first treatment with an overlap ≥90 days. Switching was defined as the transition to a new ADHD treatment after or shortly before the previous one was discontinued (switching to monotherapy or combination therapy, respectively). Mean daily dose (MDD) per patient (calculated for comparison with dosing guidelines) was defined as the total ADHD drug dose dispensed to the patient/total number of days on drug.

Comorbid Psychiatric Illnesses and Concomitant Medications

Common comorbidities (e.g., depression, anxiety disorder, and bipolar disorder) (Supplemental Table 1) of interest were identified from the NPR based on patients’ registered primary/secondary diagnoses. The analyses of comorbidities were conducted on the cross-sectional study data set (Cohort A) and for patients during ADHD medication (measured in “person-years,” which represent the aggregated number of years on treatment for each patient). Concomitant medication was identified as an entry in the PDR during the same period as ADHD medication or during the period of interest; the analyses of concomitant psychiatric medications were conducted on the cross-sectional study data set (Cohort A) and for patients during ADHD medication (defined as “person-years”).

Statistical Analysis

Statistical analyses were conducted using SAS version 9.4 and R3.5.2 (SAS Institute, Cary, NC, USA). Descriptive statistics were used to describe prevalence, incidence, comorbidities, and concomitant treatment in the longitudinal and cross-sectional study populations. Continuous data were expressed as the mean, standard deviation, and/or median, while categorical data were expressed as frequency and percentages. Where relevant, data were stratified by age group and sex. The use of each drug (overall and for each line of treatment) was presented as frequency and percentage. Analyses of time-to-treatment initiation (first line, without censoring), treatment duration, and time-to-treatment switch analyses were modeled using Kaplan–Meier estimates, in which censored individuals were considered to have the same prospect of being/not being on treatment as patients who continued to be followed. Estimates of time-to-treatment switch included newly diagnosed patients who received ≥2 lines (first to second line) and ≥3 lines of treatment (second to third line). Treatment duration was analyzed after adjusting for actual start and end date of treatment episodes, and evaluated on the basis of treatment line and stratified by sex and age group. Sankey diagrams were used to visualize treatment pathways, depict unique sequences of ADHD treatments and quantify patients via different pathways. Dosing analyses were conducted using the longitudinal dataset.

Results

Incidence and Prevalence

Between 2018 and 2020, the prevalence of ADHD in Sweden increased from 1.5% to 1.8% (Table 1), and incidence increased from 0.2% to 0.3% (Table 1). Diagnosis of ADHD occurred more frequently in children/adolescents and males, than in adults and females, respectively.

Table 1.

ADHD Prevalence and Incidence^a (Cohort A).

	2018	2019	2020
Prevalence for patients^b with either an ADHD diagnosis or a first ADHD medication prescribed, % (n)
Overall	1.5 (151,477)	1.6 (166,946)	1.8 (184,148)
0–17 years	2.7 (58,320)	3.0 (63,720)	3.2 (70,437)
≥18 years	1.2 (93,157)	1.3 (103,226)	1.4 (113,711)
Male	1.7 (87,818)	1.8 (95,685)	2.0 (104,375)
0–17 years	3.6 (40,070)	3.9 (43,429)	4.3 (47,493)
≥18 years	1.2 (47,748)	1.3 (52,256)	1.4 (56,882)
Female	1.3 (63,659)	1.4 (71,261)	1.6 (79,773)
0–17 years	1.8 (18,250)	1.9 (20,291)	2.2 (22,944)
≥18 years	1.1 (45,409)	1.3 (50,970)	1.4 (56,829)
Incidence of newly diagnosed ADHD, % (n)
Overall	0.2 (24,371)	0.3 (27,176)	0.3 (30,484)
0–17 years	0.6 (13,091)	0.7 (14,949)	0.8 (17,428)
≥18 years	0.1 (11,280)	0.2 (12,227)	0.2 (13,056)
Male	0.3 (13,548)	0.3 (15,229)	0.3 (16,743)
0–17 years	0.8 (8,202)	0.8 (9,310)	1.0 (10,639)
≥18 years	0.1 (5,346)	0.2 (5,919)	0.2 (6,104)
Female	0.2 (10,823)	0.2 (11,947)	0.3 (13,741)
0–17 years	0.5 (4,889)	0.5 (5,639)	0.6 (6,789)
≥18 years	0.2 (5,934)	0.2 (6,308)	0.2 (6,952)

Note. ATC = anatomical therapeutic chemical; ICD-10 = International Statistical Classification of Diseases and Related Health Problems 10th revision; NPR = National Patient Register; PDR = Prescribed Drug Register.

Percentage was calculated as the total number of patients with ADHD divided by the total number of the Swedish population that year.

All patients identified by ICD-10 codes (F90 and F98.8) in NPR between January 1, 2018, and December 31, 2020, and/or identified by ATC codes (N06BA01, N06BA02, N06BA04, N06BA09, N06BA12, and C02AC02) in PDR from January 1, 2018, until August 31, 2021, the latest date of data captured population in that specific year.

Treatment Patterns

A total of 243,790 patients were identified for Cohort A (comprising patients registered in the NPR between 2018 and 2020 and/or prescribed ADHD medication between 2018 and 2021), of whom 205,991 (84.5%) received an ADHD prescription between 2018 and 2021 (Cohort A1). Prescriptions for ADHD treatments were more common in adults (n = 119,588; 58.1%) than in children (n = 86,403; 41.9%) and in males (n = 117,771; 57.2%) than in females (n = 88,220; 42.8%). The newly diagnosed cohort comprised 96,951 patients with ADHD (Cohort B) of whom 57,297 (59.1%) were prescribed medication between 2018 and 2021. Table 2 highlights the ADHD medications dispensed for patients with ADHD between 2018 and 2021 (includes all patients with an ADHD prescription identified from the PDR from 2018 to 2021; Cohort A1). Overall, MPH was the most commonly dispensed medication (73.5% of patients), followed by LDX (48.5%), and ATX (14.5%). Fewer patients were prescribed DEX (9.2%), GXR (9.3%), or AMP (0.6%).

Table 2.

ADHD Medications for Patients^a with at Least One Dispensation of ADHD Medication, Stratified by Sex and Age Group (2018–2021, Cohort A1).

	Among patients with ADHD medications, n (%)^b
	Methylphenidate	Atomoxetine	Lisdexamfetamine	Guanfacine	Dexamphetamine	Amphetamine
Overall	151,472 (73.5)	29,878 (14.5)	99,864 (48.5)	19,189 (9.3)	18,933 (9.2)	1,142 (0.6)
0–17 years	72,590 (84.0)	16,172 (18.7)	37,323 (43.2)	13,864 (16.0)	2,712 (3.1)	3 (0.0)
≥18 years	78,882 (66.0)	13,706 (11.5)	62,541 (52.3)	5,325 (4.5)	16,221 (13.6)	1,139 (1.0)
Male	87,187 (74.0)	17,598 (14.9)	54,500 (46.3)	12,777 (10.8)	9,535 (8.1)	424 (0.4)
Female	64,285 (72.9)	12,280 (13.9)	45,364 (51.4)	6,412 (7.3)	9,398 (10.7)	718 (0.8)

Note. ATC = anatomical therapeutic chemical; PDR = Prescribed Drug Register.

All patients identified by ATC codes (N06BA01, N06BA02, N06BA04, N06BA09, N06BA12, and C02AC02) in PDR from January 1, 2018, until August 31, 2021, the latest date of data captured.

Percentages calculated as the number of patients with ADHD dispensed with that treatment, divided by the total number of patients with ADHD in that specific row.

Of the 205,991 patients who received an ADHD prescription between 2018 and 2021 (Cohort A1), 121,983 (59.2%) received a first-line medication, 94,796 (46.0%) received a second-line medication and 67,804 (32.9%) received a third-line medication (Table 3). The most common first-line treatments were MPH (81.6%), LDX (10.5%), and ATX (5.4%). MPH was prescribed at a similar frequency in males and females (82.6% vs. 80.2%, respectively), and more often in children/adolescents than in adults (88.7% vs. 73.5%, respectively), while LDX was used more often in adults (16.6%) than in children/adolescents (5.2%). ATX was prescribed for 6.8% of adults and 4.1% of children/adolescents in the first-line setting.

Table 3.

Frequency of First-, Second-, and Third-line ADHD Treatments for Patients^a Who had ADHD Medication Dispensed (2018–2021, Cohort A1): Overall, and Stratified by Sex and Age Group.

Number of patients (%^b)
Treatments by lines	Overall	Sex		Age group (years)
Treatments by lines		Male	Female	0–17	≥18
First-line treatment (n)	121,983	69,194	52,789	64,945	57,038
Amphetamine	386 (0.3)	151 (0.2)	235 (0.5)	4 (0.0)	382 (0.7)
Atomoxetine	6,560 (5.4)	3,633 (5.3)	2,927 (5.5)	2,662 (4.1)	3,898 (6.8)
Dexamphetamine	604 (0.5)	286 (0.4)	318 (0.6)	40 (1.0)	564 (1.0)
Guanfacine	1,699 (1.4)	1,046 (1.5)	653 (1.2)	1,118 (1.7)	581 (1.0)
Lisdexamfetamine	12,842 (10.5)	6,698 (9.7)	6,144 (11.6)	3,381 (5.2)	9,461 (16.6)
Lisdexamfetamine + dexamphetamine	101 (0.1)	56 (0.1)	45 (0.1)	3 (0.0)	98 (0.2)
Methylphenidate	99,497 (81.6)	57,176 (82.6)	42,321 (80.2)	57,598 (88.7)	41,899 (73.5)
Methylphenidate + lisdexamfetamine	141 (0.1)	56 (0.1)	85 (0.2)	34 (0.1)	107 (0.2)
Others	153 (0.1)	92 (0.1)	61 (0.1)	32 (0.1)	6 (0.0)
Second-line treatments (n)	94,796	53,367	41,429	49,897	44,899
Amphetamine	311 (0.3)	105 (0.2)	206 (0.5)	8 (0.0)	303 (0.7)
Atomoxetine	7,324 (7.7)	4,368 (8.2)	2,956 (7.1)	4,912 (9.8)	2,412 (5.4)
Atomoxetine + methylphenidate	228 (0.2)	149 (0.3)	79 (0.2)	157 (0.3)	71 (0.2)
Dexamphetamine	2,212 (2.3)	1,127 (2.1)	1,085 (2.6)	290 (0.6)	1,922 (4.3)
Guanfacine	3,229 (3.4)	2,177 (4.1)	1,052 (2.5)	2,639 (5.3)	590 (1.3)
Guanfacine + methylphenidate	82 (0.1)	55 (0.1)	27 (0.1)	64 (0.1)	18 (0.0)
Lisdexamfetamine	43,632 (46.0)	23,135 (43.4)	20,497 (49.5)	20,343 (40.8)	23,289 (51.9)
Lisdexamfetamine + guanfacine	116 (0.1)	72 (0.1)	44 (0.1)	76 (0.2)	40 (0.1)
Lisdexamfetamine + dexamphetamine	420 (0.4)	226 (0.4)	194 (0.5)	15 (0.0)	405 (0.9)
Lisdexamfetamine + methylphenidate	153 (0.2)	81 (0.2)	72 (0.2)	45 (0.1)	108 (0.2)
Methylphenidate	33,121 (34.9)	19,328 (36.2)	13,793 (33.3)	18,870 (37.8)	14,251 (31.7)
Methylphenidate + atomoxetine	681 (0.7)	499 (0.9)	182 (0.4)	608 (1.2)	73 (0.2)
Methylphenidate + dexamphetamine	64 (0.1)	36 (0.1)	28 (0.1)	7 (0.0)	57 (0.1)
Methylphenidate + guanfacine	761 (0.8)	570 (1.1)	191 (0.5)	681 (1.4)	80 (0.2)
Methylphenidate + lisdexamfetamine	2,273 (2.4)	1,317 (2.5)	956 (2.3)	1,056 (2.1)	1,217 (2.7)
Others	189 (0.2)	122 (0.2)	67 (0.2)	23 (0.1)	6 (0.0)
Third-line treatment (n)	67,804	38,524	29,280	36,943	30,861
Amphetamine	229 (0.3)	80 (0.2)	149 (0.5)	8 (0.0)	221 (0.7)
Atomoxetine	7,332 (10.8)	4,281 (11.1)	3,051 (10.4)	5,034 (13.6)	2,298 (7.5)
Atomoxetine + guanfacine	102 (0.2)	80 (0.2)	22 (0.1)	94 (0.3)	8 (0.0)
Atomoxetine + lisdexamfetamine	223 (0.3)	159 (0.4)	64 (0.2)	194 (0.5)	29 (0.1)
Atomoxetine + methylphenidate	148 (0.2)	117 (0.3)	31 (0.1)	133 (0.4)	15 (0.1)
Dexamphetamine	6,011 (8.9)	2,965 (7.7)	3,046 (10.4)	1,009 (2.7)	5,002 (16.2)
Dexamphetamine + lisdexamfetamine	80 (0.1)	51 (0.1)	29 (0.1)	3 (0.0)	77 (0.3)
Guanfacine + lisdexamfetamine	214 (0.3)	158 (0.4)	56 (0.2)	183 (0.5)	31 (0.1)
Guanfacine	4,890 (7.2)	3,288 (8.5)	1,602 (5.5)	3,940 (10.7)	950 (3.1)
Guanfacine + methylphenidate	93 (0.1)	68 (0.2)	25 (0.1)	86 (0.2)	7 (0.0)
Lisdexamfetamine	22,301 (32.9)	12,110 (31.4)	10,191 (34.8)	11,052 (29.9)	11,249 (36.5)
Lisdexamfetamine + atomoxetine	204 (0.3)	118 (0.3)	86 (0.3)	124 (0.3)	80 (0.3)
Lisdexamfetamine + dexamphetamine	527 (0.8)	282 (0.7)	245 (0.8)	86 (0.2)	441 (1.4)
Lisdexamfetamine + guanfacine	222 (0.3)	145 (0.4)	77 (0.3)	169 (0.5)	53 (0.2)
Lisdexamfetamine + methylphenidate	532 (0.8)	308 (0.8)	224 (0.8)	208 (0.6)	324 (1.1)
Methylphenidate	24,317 (35.9)	14,079 (36.6)	10,238 (35.0)	14,419 (39.0)	9,898 (32.1)
Methylphenidate + atomoxetine	78 (0.1)	51 (0.1)	27 (0.1)	45 (0.1)	33 (0.1)
Methylphenidate + lisdexamfetamine	93 (0.1)	54 (0.1)	39 (0.1)	52 (0.1)	41 (0.1)
Others	208 (0.3)	130 (0.3)	78 (0.3)	22 (0.1)	10 (0.0)

Note. ATC = anatomical therapeutic chemical; PDR = Prescribed Drug Register.

All patients identified by ATC codes (N06BA01, N06BA02, N06BA04, N06BA09, N06BA12, and C02AC02) in PDR from January 1, 2018, until August 31, 2021, the latest date of data captured.

Percentages calculated as the number of patients with ADHD who are on their first, second, or third line of treatment, divided by the overall number of patients with ADHD for first, second, or third line of treatment, respectively, for the given subgroup.

The above three treatment options remained the most frequently prescribed medications in the second- and third-line settings. For second-line treatment, LDX was most frequently prescribed (46.0%), followed by MPH (34.9%), then ATX (7.7%). For third-line treatment, MPH was most frequently prescribed (35.9%), followed by LDX (32.9%), then ATX (10.8%). GXR and DEX (1.4% and 0.5%, respectively) were rarely used as first-line monotherapy treatments, but more frequently prescribed in the second-line (3.4% and 2.3%, respectively) and third-line (7.2% and 8.9%, respectively) settings. Generally, across treatment lines, differences between males and females were small, although larger differences were found between adult and children/adolescent populations. Combination treatments were more often used in second-line (9/15 [60.0%]) and third-line (12/18 [66.7%]) settings, compared with the first line (2/8 [25.0%]) (Table 3).

Time-to-first-line treatment initiation (i.e., from diagnosis to dispensing [Cohort B; comprising patients with a first diagnosis and/or prescription for ADHD between 2018 and 2020]) was shortest for patients receiving MPH, LDX, and DEX monotherapy (median 0.5 months for all), and longest for patients receiving ATX or GXR monotherapy (median 0.7 and 0.6 months, respectively) (Supplemental Table 2). Overall, patients continued taking LDX for longer than other available medications (median 10.4 months; 95% CI [10.2, 10.6]), followed by AMP (median 9.1 months; 95% CI [8.0, 10.2]). Median treatment duration for GXR (median 6.0 months; 95% CI [5.8, 6.3]) and MPH (median 5.9 months; 95% CI [5.9, 6.0]) was similar, being slightly higher than for ATX (median 3.7 months; 95% CI [3.6, 3.8]) (Figure 1).

Figure 1.

Treatment duration for ADHD medications regardless of treatment line (months).

Unsurprisingly, the median treatment duration for each medication varied across treatment lines (Table 4). Median treatment duration for MPH decreased from 6.8 months during first-line treatment, to 5.2 and 4.2 months for second- and third-line treatment, respectively. Similarly, median treatment duration for AMP decreased from 13.2 months during first-line treatment to 12.3 months during second-line treatment. Interestingly, LDX treatment duration was similar during first-line (median 13.3 months) and second-line (13.7 months) treatment, decreasing to 9.0 months with third-line use. In contrast, the duration of GXR and DEX treatment increased from first to third line (GXR medians 5.2, 10.1, and 8.4 months; DEX medians 4.5, 4.9, and 5.1 months, respectively). Patient age also impacted treatment duration; for example, MPH, ATX, and GXR were all used for longer by children/adolescents than by adults, irrespective of treatment line. In contrast, LDX and DEX treatment duration was longer in adults than in children/adolescents across all treatment lines.

Table 4.

Treatment Durationa (Months) by ADHD Medication for Patientsb Who had at Least One ADHD Medication Dispensed (2018–2021, Cohort A1): Overall, and Stratified by Sex and Age Group.

		Sex		Age group, years
	Overall	Female	Male	0–17	≥18
	Median [95% CI]	Median [95% CI]	Median [95% CI]	Median [95% CI]	Median [95% CI]
First-line treatment
Amphetamine	13.2 [10.7, 18.3]	11.4 [9.6, 18.7]	15.1 [11.4, NA]	NA [NA, NA]	12.9 [10.6, 17.8]
Atomoxetine	3.5 [3.3, 3.7]	3.4 [3.2, 3.7]	3.6 [3.4, 3.8]	4.6 [4.2, 4.9]	2.7 [2.5, 2.9]
Dexamphetamine	4.5 [4.0, 5.0]	4.0 [3.2, 4.8]	4.9 [4.2, 5.7]	1.1 [NA, NA]	5.3 [4.8, 6.2]
Guanfacine	5.2 [4.7, 5.9]	3.8 [3.2, 4.5]	6.3 [5.5, 7.2]	7.5 [6.5, 8.6]	2.4 [2.1, 2.8]
Lisdexamfetamine	13.3 [12.9, 13.7]	13.5 [12.9, 14.1]	13.2 [12.7, 13.7]	9.4 [8.9, 9.8]	17.1 [16.5, 17.8]
Lisdexamfetamine + dexamphetamine	18.5 [14.1, 24.5]	14.1 [11.9, 19.2]	25.7 [16.8, NA]	36.8 [8.8, NA]	18.5 [14.1, 24.5]
Lisdexamfetamine + guanfacine	9.9 [6.7, 19.3]	13.3 [6.8, 27.2]	9.1 [5.8, 19.6]	9.1 [5.7, 19.3]	11.7 [6.3, 34.5]
Methylphenidate	6.8 [6.7, 7.0]	5.8 [5.7, 6.0]	7.8 [7.6, 8.0]	7.9 [7.7, 8.0]	5.4 [5.3, 5.6]
Methylphenidate + atomoxetine	9.2 [7.7, 12.0]	8.3 [6.3, 12.8]	9.5 [7.7, 13.1]	9.5 [7.7, 12.5]	9.0 [5.4, 13.9]
Methylphenidate + guanfacine	10.9 [9.3, 12.9]	10.4 [8.3, 12.9]	11.5 [9.5, 13.7]	10.9 [9.3, 13.6]	10.4 [6.6, 13.4]
Methylphenidate + lisdexamfetamine	4.5 [4.4, 4.7]	4.6 [4.4, 4.9]	4.5 [4.4, 4.7]	4.3 [4.1, 4.5]	4.9 [4.6, 5.2]
Second-line treatment
Amphetamine	12.3 [8.4, 23.1]	10.8 [7.9, NA]	23.1 [3.5, NA]	NA [NA, NA]	10.8 [8.1, 21.8]
Atomoxetine	4.3 [4.0, 4.5]	4.0 [3.7, 4.4]	4.5 [4.1, 5.0]	5.2 [4.8, 5.8]	2.7 [2.3, 3.1]
Dexamphetamine	4.9 [4.6, 5.6]	4.6 [4.0, 5.3]	5.6 [4.8, 6.7]	1.1 [NA, NA]	6.6 [5.9, 7.5]
Guanfacine	10.1 [8.8, 11.4]	7.8 [6.3, 8.7]	12.0 [10.1, 14.1]	13.1 [11.4, 16.3]	3.2 [2.5, 4.1]
Lisdexamfetamine	13.7 [13.3, 14.2]	13.3 [12.8, 14.0]	14.1 [13.4, 14.8]	9.3 [9.0, 9.7]	20.6 [19.3, 21.9]
Lisdexamfetamine + atomoxetine	10.4 [6.3, 23.0]	7.3 [4.8, 11.47]	13.1 [6.3, 25.9]	18.5 [5.1, NA]	7.3 [5.3, 13.1]
Lisdexamfetamine + dexamphetamine	10.7 [8.7, 12.3]	10.6 [8.3, 13.2]	10.7 [8.2, 14.5]	NA [10.3, NA]	10.3 [8.5, 11.4]
Lisdexamfetamine + guanfacine	11.2 [7.2, 16.8]	7 [4.6, 9.5]	18.3 [11.2, NA]	11.9 [7.2, NA]	8.0 [6.2, 13.2]
Methylphenidate	5.2 [5.0, 5.3]	4.6 [4.4, 4.8]	5.4 [5.3, 5.6]	5.3 [5.2, 5.5]	4.7 [4.4, 4.9]
Methylphenidate + atomoxetine	7.3 [6.3, 8.1]	7.3 [5.7, 8.8]	7.3 [6.3, 8.4]	7.0 [6.2, 7.8]	8.4 [5.7, 19.7]
Methylphenidate + guanfacine	9.4 [8.2, 11.2]	7.9 [6.5, 9.0]	10.7 [8.9, 13.2]	9.6 [8.4, 12.1]	6.7 [3.8, 10.6]
Methylphenidate + lisdexamfetamine	4.3 [4.1, 4.4]	4.3 [4.11, 4.5]	4.3 [4.1, 4.5]	4.2 [4.0, 4.3]	4.5 [4.2, 4.7]
Third-line treatment
Atomoxetine	3.8 [3.5, 4.1]	3.3 [2.9, 3.8]	4.2 [3.8, 4.8]	4.7 [4.2, 5.3]	2.3 [2.0, 2.7]
Dexamphetamine	5.1 [4.6, 5.7]	4.3 [3.6, 4.9]	6.3 [5.3, 7.3]	1.1 [NA, NA]	6.3 [5.7, 7.1]
Guanfacine	8.7 [7.5, 9.6]	4.9 [4.1, 6.3]	10.9 [9.2, 13.7]	10.6 [9.2, 13.0]	3.3 [2.7, 4.4]
Guanfacine + lisdexamfetamine	NA [18.7, NA]	NA [16.4, NA]	NA [18.7, NA]	NA [NA, NA]	10.5 [6.1, NA]
Lisdexamfetamine	9.0 [8.3, 9.6]	9.0 [8.1, 9.9]	9.0 [8.0, 10.0]	7.26 [6.7, 7.8]	12.5 [11.1, 14.5]
Lisdexamfetamine + dexamphetamine	NA [NA, NA]	NA [16.4, NA]	NA [25.9, NA]	NA [12.8, NA]	NA [28.9, NA]
Lisdexamfetamine + methylphenidate	24.6 [18.6, NA]	NA [15.1, NA]	22.3 [18.6, NA]	19.0 [4.9, NA]	NA [18.6, NA]
Methylphenidate	4.2 [3.9, 4.5]	3.6 [3.2, 3.8]	5.0 [4.5, 5.3]	4.8 [4.4, 5.3]	3.3 [3.0, 3.6]

Note. ATC = anatomical therapeutic chemical; NA = not applicable; PDR = Prescribed Drug Register.

Adjusted for actual start and end date of treatment episodes.

All patients identified by ATC codes (N06BA01, N06BA02, N06BA04, N06BA09, N06BA12, and C02AC02) in PDR from January 1, 2018, until August 31, 2021, the latest date of data captured.

The majority of patients treated with first-line MPH, LDX, and ATX switched treatment; of those given second-line MPH, LDX, and ATX, around half received third-line treatment, with most switching to a different medication. Around half of patients prescribed first-line MPH switched to second-line LDX; of those given second-line MPH, the most frequent third-line switch was to LDX. After first-line LDX, the most frequent second-line treatment was MPH; patients given second-line LDX switched to one of four third-line treatments (either MPH, ATX, DEX, or GXR). Following first-line treatment with ATX, MPH was the usual second-line treatment prescribed; after second-line ATX, prescribed third-line treatments varied (Figure 2). Dosing analyses indicated that the MDD for all drugs dispensed was largely in line with the recommended daily dose as advised by the WHO (2022). Most patients receiving above the maximum recommended dose were taking extended-release MPH (15% in children/adolescents and 25% in adults), with fewer excursions above the recommended dose using the other two MPH formulations (modified release [2% and 9%, respectively] and immediate release [rare and 3%, respectively]). Similar patterns were noted for LDX (3% in children/adolescents; 16% in adults) and DEX (rare in children/adolescents; 6% in adults).

Figure 2.

Treatment switching patterns.

Comorbid Psychiatric Illnesses and Concomitant Medications

Table 5 shows the psychiatric comorbidities that were diagnosed among the patients included in this analysis. In total, 9,292 (38.1%) of 24,371 patients newly diagnosed with ADHD in 2018 had a psychiatric comorbidity within 1 year of diagnosis. In 2019, 10,220 (37.6%) of 27,176 patients newly diagnosed with ADHD had a psychiatric comorbidity within 1 year of diagnosis. Psychiatric comorbidities were seen in ~30.0% of children/adolescents and 45.0% of adults. The most common condition (based on ICD-10 comorbidity codes listed in Supplemental Table 1) among children/adolescents was autism (46.1% and 45.2% of patients in 2018 and 2019, respectively). Depression was the most common comorbidity among adults (38.8% in 2018; 40.2% in 2019), followed by anxiety disorder (33.7% [2018]; 44.7% [2019]). In total, between 2018 and 2021, most patients (~60%) were taking concomitant psychiatric medication. Within 1 year of diagnosis in 2018 and 2019 (Table 6), hypnotics were the most commonly used overall (74.1% [2018] and 75% [2019] of patients), along with antidepressants (49.4% [2018] and 48.8% [2019]), which were most frequently used by females.

Table 5.

Psychiatric Comorbidities within 1 Year after Diagnosis for Newly Diagnosed Patients with ADHD,^a Stratified by Sex and Age Group (Total for Sweden, 2018–2019).

	Newly diagnosed patients with ADHD	Patients with comorbidities (n, %)	Substance-related disorder (n, %)	Schizophrenia (n, %)	Bipolar disorder (n, %)	Depression (n, %)	Anxiety disorder (n, %)	Obsessive -compulsive disorder (n, %)	Eating disorder (n, %)	Personality disorder (n, %)	Impulse control disorder (n, %)	Mild intellectual disabilities (n, %)	Autism (n, %)	Oppositional defiant disorder (n, %)	Combined vocal (n, %)
2018
Total	24,371	9,292 (38.1)	953 (10.3)	51 (0.5)	672 (7.2)	2,948 (31.7)	2,845 (30.6)	322 (3.5)	216 (2.3)	579 (6.2	58 (0.6)	358 (3.9)	2,964 (31.9)	427 (4.6)	163 (1.8)
Age 0–17 years	13,091	4,091 (31.3)	118 (2.9)	4 (0.1)	40 (1)	932 (22.8)	1,093 (26.7)	156 (3.8)	95 (2.3)	16 (0.4)	36 (0.9)	220 (5.4)	1,887 (46.1)	426 (10.4)	132 (3.2)
Age ≥18 years	11,280	5,201 (46.1)	835 (16.1)	47 (0.9)	632 (12.2)	2,016 (38.8)	1,752 (33.7)	166 (3.2)	121 (2.3)	563 (10.8)	22 (0.4)	138 (2.7)	1,077 (20.7)	1 (0)	31 (0.6)
Male	13,548	4,561 (33.7)	602 (13.2)	29 (0.6)	251 (5.5)	1,154 (25.3)	997 (21.9)	138 (3)	24 (0.5)	139 (3)	35 (0.8)	213 (4.7)	1,846 (40.5)	302 (6.6)	134 (2.9)
Female	10,823	4,731 (43.7)	351 (7.4)	22 (0.5)	421 (8.9)	1,794 (37.9)	1,848 (39.1)	184 (3.9)	192 (4.1)	440 (9.3)	23 (0.5)	145 (3.1)	1,118 (23.6)	125 (2.6)	29 (0.6)
2019
Total	27,176	10,220 (37.6)	1,048 (10.3)	52 (0.5)	639 (6.3)	3,263 (31.9)	3,171 (31)	405 (4)	220 (2.2)	561 (5.5)	63 (0.6)	429 (4.2)	3,314 (32.4)	525 (5.1)	164 (1.6)
Age 0–17 years	14,949	4,698 (31.4)	166 (3.5)	0 (0)	51 (1.1)	1,041 (22.2)	1,254 (26.7)	180 (3.8)	95 (2)	11 (0.2)	46 (1)	276 (5.9)	2,124 (45.2)	525 (11.2)	135 (2.9)
Age ≥18 years	12,227	5,522 (45.2)	882 (16)	52 (0.9)	588 (10.6)	2,222 (40.2)	1,917 (34.7)	225 (4.1)	125 (2.3)	550 (10)	17 (0.3)	153 (2.8)	1,190 (21.6)	0 (0)	29 (0.5)
Male	15,229	5,083 (33.4)	668 (13.1)	39 (0.8)	229 (4.5)	1,272 (25)	1,137 (22.4)	190 (3.7)	32 (0.6)	143 (2.8)	36 (0.7)	262 (5.2)	2,034 (40)	380 (7.5)	116 (2.3)
Female	11,947	5,137 (43)	380 (7.4)	13 (0.3)	410 (8)	1,991 (38.8)	2,034 (39.6)	215 (4.2)	188 (3.7)	418 (8.1)	27 (0.5)	167 (3.3)	1,280 (24.9)	145 (2.8)	48 (0.9)

Note. ATC = anatomical therapeutic chemical; ICD-10 = International Statistical Classification of Diseases and Related Health Problems 10th revision; NPR = National Patient Register; PDR = Prescribed Drug Register.

All patients identified by ICD-10 codes (F90 and F98.8) in NPR between January 1, 2018, and December 31, 2020, AND/OR identified by ATC codes (N06BA01, N06BA02, N06BA04, N06BA09, N06BA12, and C02AC02) in PDR from January 1, 2018, until August 31, 2021, who did not have any ADHD diagnosis or ADHD drug dispensations prior to January 1, 2018.

Table 6.

Concomitant Psychiatric Medications within 1 Year after ADHD Diagnosis for Newly Diagnosed Patients with ADHD,a Stratified by Sex and Age Group (Total for Sweden, 2018–2019).

	Newly diagnosed patients with ADHD	Patients with concomitant medications (n, %)	Antidepressants	Antipsychotics	Anxiolytics	Hypnotics	Promethazine	Lithium
2018
Total	24,371	14,600 (59.9)	7,211 (49.4)	1,936 (13.3)	3,601 (24.7)	10,824 (74.1)	5 (0)	229 (1.6)
Age 0–17 years	13,091	6,886 (52.6)	1,882 (27.3)	487 (7.1)	1,030 (15)	6,089 (88.4)	0 (0)	12 (0.2)
Age ≥18 years	11,280	7,714 (68.4)	5,329 (69.1)	1,449 (18.8)	2,571 (33.3)	4,735 (61.4)	5 (0.1)	217 (2.8)
Male	13,548	7,225 (53.3)	2,908 (40.2)	969 (13.4)	1,423 (19.7)	5,527 (76.5)	2 (0)	105 (1.5)
Female	10,823	7,375 (68.1)	4,303 (58.3)	967 (13.1)	2,178 (29.5)	5,297 (71.8)	3 (0)	124 (1.7)
2019
Total	27,176	16,432 (60.5)	8,021 (48.8)	2,046 (12.5)	3,714 (22.6)	12,320 (75)	6 (0)	249 (1.5)
Age 0–17 years	14,949	7,981 (53.4)	2,155 (27)	549 (6.9)	1,117 (14)	7,076 (88.7)	1 (0)	21 (0.3)
Age ≥18 years	12,227	8,451 (69.1)	5,866 (69.4)	1,497 (17.7)	2,597 (30.7)	5,244 (62.1)	5 (0.1)	228 (2.7)
Male	15,229	8,217 (54)	3,248 (39.5)	1,033 (12.6)	1,474 (17.9)	6,419 (78.1)	1 (0)	109 (1.3)
Female	11,947	8,215 (68.8)	4,773 (58.1)	1,013 (12.3)	2,240 (27.3)	5,901 (71.8)	5 (0.1)	140 (1.7)

Note. ATC = Anatomical therapeutic chemical; ICD-10 = International Statistical Classification of Diseases and Related Health Problems 10th revision; NPR = National Patient Register; PDR = Prescribed Drug Register.

All patients identified by ICD-10 codes (F90 and F98.8) in NPR between January 1, 2018, and December 31, 2020, AND/OR identified by ATC codes (N06BA01, N06BA02, N06BA04, N06BA09, N06BA12, and C02AC02) in the PDR from January 1, 2018, until August 31, 2021, who did not have any ADHD diagnosis or ADHD drug dispensations prior to January 1, 2018.

Discussion

This nationwide registry study, conducted in Sweden between 2018 and 2021, and involving almost a quarter of a million children/adolescents and adults with ADHD, provides real-life insights into the current epidemiology of ADHD and the changing treatment landscape for patients in Sweden. The sourcing of information from both the NPR and PDR ensured comprehensive datasets, and the

establishment of such registers has been shown to encourage an increased level of pharmacoepidemiologic research in Sweden (Wallerstedt et al., 2016).

Although the latter part of the study period coincided with the start of the COVID-19 pandemic, we did not observe a decrease in ADHD prevalence, which might have been expected as a result of reduced access to healthcare services during this time. Indeed, our data showed that ADHD prevalence increased in Sweden between 2018 and 2021, with rates increasing from 2.7% to 3.2% in children/adolescents and from 1.2% to 1.4% in adults. These prevalence rates were generally consistent with those found in earlier studies (Giacobini et al., 2018; Polyzoi et al., 2018), although prevalence does vary across geographic regions and countries (Posner et al., 2020). Such differences are likely to be related to methodologic issues between studies, such as in diagnostic criteria, information sources and, in some cases, the requirement for functional disability to be part of the ADHD diagnosis (Posner et al., 2020).

Among the 243,790 individuals with ADHD included in our study, 84.5% had at least one ADHD medication dispensed, with the median time-to-initiation of first-line treatment differing between medications (0.5–0.7 months). The delay in treatment initiation observed in this study may also have been related to delays in accessing prescribing specialists following diagnosis. Additionally, a small number of patients may have received medication in the clinic and not via the pharmacy (thus treatment would not have been captured in the PDR). Consistent with European and Swedish guidelines (Kooij et al., 2019; Swedish Medical Products Agency, 2016), MPH was the most commonly used medication among our population, and the most frequently used first-line treatment. Nevertheless, our data suggest that new ADHD medications are beginning to influence treatment patterns; LDX (unavailable in Sweden at the time of the study by Giacobini et al. (2018). Giacobini et al. (2018) was the next most commonly dispensed treatment and the most frequently used second-line treatment. Although LDX is currently only recommended as a second-line treatment, it was used by >10% of patients in the first-line setting. Additionally, neither GXR or DEX are approved for first-line treatment in children, but were used, respectively, in ~2% and ~5% of patients under the age of 18. These findings suggest that the provision of newer treatments is not always in alignment with national guidelines. This could reflect the need for updated treatment guidelines for ADHD in Sweden, in light of the changing treatment landscape. Initial non-pharmacologic management of ADHD is recommended before starting medication, particularly in children. Evidence has shown that structured psychoeducation programs can increase patients and their significant others’ knowledge about ADHD, and improve the quality of their relationships and psychological well-being (Kooij et al., 2019).

The availability of multiple treatment options allowed us to examine the duration of treatment and the frequency of switches with each drug. Treatment duration among all treated patients was longer for LDX and AMP compared with ATX, DEX, MPH, and GXR; patients who switched generally did so more quickly from taking MPH than they did from taking LDX. A recent study found that, among patients prescribed a stimulant first line, 24.0% switched to another agent within 60 days, mostly because of poor tolerability (Biederman et al., 2021). In a Danish study, among 55 children/adolescents with ADHD prescribed MPH first line, 36.0% switched treatments during the first 6 months (Warrer et al., 2016). A variety of factors likely contributed to the switch, including adverse effects, non-optimal day coverage, lack of efficacy, patient/parental preferences, and non-compliance (Warrer et al., 2016). Another Danish study found that, in 2000, 20.8% of patients discontinued ADHD medication (limited to MPH and ATX) within 6 months; this had reduced to 12.5% by 2012 (Pottegard et al., 2015). Hart et al. (2021) reported that adolescents tend to continue taking medication more often than young adults; 77.0% of patients aged 11 to 12 years compared with 52.0% aged 19 to 20 years (Hart et al., 2021). It seems that adolescents and young adults who have to progress from pediatric to adult services (17–18 years) continue less frequently with ADHD medication and it is well established that the management of this transition period could be improved to maintain the continuity of care in young people (Price et al., 2019).

Our study also confirms that psychiatric comorbidities are common in the ADHD population with psychotropic medications prescribed to a high proportion of these patients. The levels of psychiatric comorbidity recorded within 1 year after ADHD diagnosis in the present study were ~40%, which is comparable to observations from other datasets (Ahnemark et al., 2018; Polyzoi et al., 2018). In our study, depression and anxiety disorders were common psychiatric comorbidities, which were more frequent in women.

The strengths of this study include that it is an analysis of nationwide data, based on all patients with a registered ADHD diagnosis and/or their individual pharmacologic treatments, that has a long follow-up time (4 years). Limitations are that the study relied on accurate completion of patient records: data were collected from routine clinical practice, some data may be missing, and coding errors might have occurred. It is also not clear how relevant our findings are with respect to other European countries or other world regions, given that there may be significant differences in healthcare provision and funding between countries, along with cultural differences that may impact any direct comparison with the data presented here. An additional major limitation of this study is that the drugs used for treatment may differ based on the severity of the disorder in different patient populations. This must be considered when interpreting differences in outcomes, and results should be interpreted with caution.

Conclusions

In the evolving ADHD treatment landscape, this Swedish study provides some insights into how new medications are beginning to influence clinical practice and treatment patterns. Despite the greater proportion of patients still taking first-line MPH compared with newer ADHD medications, switching patterns suggest that patients receiving newer medications such as LDX or GXR may continue with their treatment longer and be less prone to switching.

Supplemental Material

sj-docx-1-jad-10.1177_10870547231177221 – Supplemental material for Epidemiology, Treatment Patterns, Comorbidities, and Concomitant Medication in Patients with ADHD in Sweden: A Registry-Based Study (2018–2021)

Supplemental material, sj-docx-1-jad-10.1177_10870547231177221 for Epidemiology, Treatment Patterns, Comorbidities, and Concomitant Medication in Patients with ADHD in Sweden: A Registry-Based Study (2018–2021) by MaiBritt Giacobini, Ewa Ahnemark, Emma Medin, Jonatan Freilich, Magnus Andersson, Yuanjun Ma and Ylva Ginsberg in Journal of Attention Disorders

Footnotes

Acknowledgements

Medical writing support for this manuscript was provided by Kate Bradford, PhD, of Parexel, under the direction of the authors, and was funded by Takeda Pharmaceuticals International AG. The authors thank Bengt Anell of Takeda for their involvement in discussion of the preliminary results, and Natalia Stelmaszuk of Parexel for analysis and quality control of the data.

Declaration of Conflicting Interests

The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: MG has served as a consultant for Eli Lilly, Janssen-Cilag and Shire (a Takeda company); has received speaker fees and reimbursement for travel costs from Nutricia; and has been a principal investigator for Novartis, Shire (a Takeda company), and Takeda. EA was employed by Shire Sweden AB (a Takeda company) at the time of this research. JF is employed by Parexel International, which has received funding from Shire (a Takeda company). EM and YM were also employed by Parexel International at the time of the study. YG has received reimbursement for travel costs, royalties, speaker fees from, and/or has served as a consultant for, Medscape, Shire (a Takeda company), and Studentlitteratur.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The original research for this study was funded by Shire Development LLC, which is now part of Takeda. The current analysis was funded by Takeda.

ORCID iD

MaiBritt Giacobini

Data Availability

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Supplemental Material

Supplemental material for this article is available online.

Author Biographies

MaiBritt Giacobini is a Senior Consultant in Child and Adolescent Psychiatry and Clinical Genetics. She is the founder of PRIMA Child and Adult Psychiatry, a healthcare company. She received her PhD in Basic Neuroscience and is affiliated with the Department of Molecular Medicine and Surgery at Karolinska Institutet, Stockholm, Sweden.

Ewa Ahnemark is a Specialist in Psychiatry, and has worked within the pharmaceutical industry for 16 years. Currently, Ewa is a Senior Psychiatrist at one of the biggest outpatient clinics in Stockholm, Sweden, where she specializes in Neuropsychiatry, mainly adult ADHD.

Emma Medin has been involved in registry-based epidemiological research for 15 years. She has supported pharmaceutical companies in various executive consultant roles for almost 20 years. Emma has a Medical Degree from Karolinska Institutet, Stockholm, Sweden, and an MSc in Economics from Stockholm University, Sweden.

Jonatan Freilich is a Senior Director at Parexel International, and acts as Principal Investigator for industry-sponsored, real-world evidence studies that use databases. Jonatan has an MSc and PhD from the Royal Institute of Technology, Stockholm, Sweden.

Magnus Andersson is a Pharmacist by training with many years’ experience working with registry studies, and has worked within the pharmaceutical industry for over 20 years. At the time of this study, Magnus was working as a Medical Advisor at Takeda; he is currently Medical Director at Merz Therapeutics Nordics.

Yuanjun Ma has been involved in drug development-related research for many years. She has a MSc in Biochemistry and a PhD in Medical Science, and is experienced in Biostatistics and Epidemiology.

Ylva Ginsberg is a Senior Consultant Psychiatrist and ADHD Researcher, and is affiliated with Karolinska Institutet, Stockholm, Sweden.

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Supplementary Material

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Epidemiology,Treatment Patterns,Comorbidities,and Concomitant Medication in Patients with ADHD in Sweden: A Registry-Based Study (2018–2021)

Abstract

Objective:

Method:

Results:

Conclusion:

Keywords

Introduction

Methods

Data Sources

Study Design

Epidemiology

Treatment Patterns

Comorbid Psychiatric Illnesses and Concomitant Medications

Statistical Analysis

Results

Incidence and Prevalence

Treatment Patterns

Comorbid Psychiatric Illnesses and Concomitant Medications

Discussion

Conclusions

Supplemental Material

sj-docx-1-jad-10.1177_10870547231177221 – Supplemental material for Epidemiology, Treatment Patterns, Comorbidities, and Concomitant Medication in Patients with ADHD in Sweden: A Registry-Based Study (2018–2021)

Footnotes

Acknowledgements

Declaration of Conflicting Interests

Funding

ORCID iD

Data Availability

Supplemental Material

Author Biographies

References

Supplementary Material