Abstract
Introduction
Pain problems are prevalent among people with ADHD. Previous research has reported that recurrent abdominal pain is associated with ADHD in children (Holmberg & Hjern, 2006) and that adults with ADHD experience higher levels of chronic and widespread pain than those without ADHD do (Kessler, Lane, Stang, & Van Brunt, 2009; Stray et al., 2013). Recent reviews have confirmed that children with ADHD are more likely to have comorbid headaches compared with those without ADHD (Paolino, Ferretti, Villa, & Parisi, 2015), and that headaches have disabling effects on children with ADHD (Parisi et al., 2014). Pain may negatively affect executive and attentional functions and therefore influence academic learning and daily activities in the long term (Moriarty, McGuire, & Finn, 2011; Riva et al., 2012). The results of previous studies support the conclusion that the experience of pain and its adverse impacts on physical and psychological well-being warrant routine monitoring among children and adolescents with ADHD.
Previous cross-sectional (Holmberg & Hjern, 2008; Yen, Yang, et al., 2014) and follow-up (Yang et al., 2013) community studies have identified children and adolescents with ADHD as a high-risk group for bullying victimization and perpetration. This not only increases the risks of depression and anxiety (Hu, Chou, & Yen, 2016) but also the risk of suicidality (Chou, Liu, Hu, & Yen, 2016) in youths with ADHD. Moreover, the experience of being the victim or perpetrator of bullying increases the likelihood of pain among adolescents (Yen, Lin, Liu, Hu, & Cheng, 2014). However, few studies have examined the relationship between bullying involvement and pain among children and adolescents with ADHD. A previous study found that bullying victimization increases the risks of abdominal pain and headaches among children with ADHD in a Swedish community (Holmberg, 2010), indicating the importance of evaluating the experiences of bullying involvement among children and adolescents with ADHD who report experiencing various forms of physical pain.
Several concerns regarding the relationships among pain, bullying involvement, and mental health problems in children and adolescents with ADHD require further study. First, previous studies on pain problems in youths with ADHD have focused on surveying the location of pain, such as the head and the abdomen, but have not evaluated youths’ perceptions of pain-induced functional impairment. An emphasis on subjective pain-induced functional impairment can improve the understanding of the viewpoints of people experiencing pain regarding the negative impacts of pain on their lives. Second, people can be the perpetrators or victims of physical, verbal, or relational bullying. Whether various types of involvement in bullying have different associations with pain in children and adolescents with ADHD has not been well documented. Third, both pain (Xie et al., 2012) and bullying involvement (Yen, Yang, et al., 2014) are significantly associated with mental health problems among children and adolescents. The question of whether pain has an independent relationship with mental health problems in youths with ADHD, after control for the effects of bullying involvement, requires further study. Fourth, a previous study on the relationship between pain and bullying involvement in children with ADHD was based on a community sample (Holmberg, 2010). Further study on children and adolescents with a clinical diagnosis of ADHD in different communities is warranted.
The aim of this study was to examine the relationships of pain and pain-induced functional impairment with various types of bullying involvement, as well as the relationships of pain and pain-induced functional impairment with mental health problems, including depression, anxiety, and poor sleep quality. We hypothesized that various types of bullying involvement have different relationships with pain and that pain is significantly associated with mental health problems after control for the effects of bullying involvement in children and adolescents with ADHD. We also hypothesized that compared with those who complain of pain but experience no significant pain-induced functional impairment, children and adolescents who report both pain and pain-induced functional impairment have more severe mental health problems.
Method
Participants
The participants in this study were recruited from two child and adolescent psychiatric outpatient clinics in Kaohsiung and Taipei, Taiwan. Children and adolescents aged between 6 and 18 years diagnosed with ADHD according to the diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; DSM-IV-TR; American Psychiatric Association [APA], 2000) were consecutively invited to participate in this study between November 2009 and July 2012. ADHD was diagnosed according to multiple data sources, including (a) an interview conducted by a child psychiatrist, (b) clinical observation of participants’ behaviors, (c) a history provided by the parents, and (d) the parent-report, shortened form of the Chinese version of the Swanson, Nolan, and Pelham, Version IV Scale (SNAP-IV; Gau, Shang, & Liu, 2008; Swanson et al., 2001). Children and adolescents who exhibited intellectual disability, schizophrenia, bipolar disorder, autistic disorder and difficulty in communicating, or any cognitive deficits that prevented them from understanding the study purpose or completing the questionnaires were excluded. A total of 579 children and adolescents diagnosed with ADHD were invited to participate in this study. Among them, 474 (81.9%) agreed to participate and were interviewed by the research assistants by using the research questionnaire. There was no significant difference in gender (χ2 = .417, p > .05) and age (t = .794, p > .05) between those who agreed and those who refused to participate. The study was approved by the Institutional Review Board of Kaohsiung Medical University and Chang Gung Memorial Hospital.
Measures
Pain
Self-reported levels of pain in the chest, abdomen, neck and shoulders, back and extremities, and head as well as pain-induced functional impairment in the month preceding the study were assessed using the Visual Analog Scale with ratings from 0 to 100. Those who rated their level of pain in any part of the body as 50 or higher were classified as experiencing significant pain. Those who rated their level of pain-induced functional impairment as 50 or higher were classified as experiencing significant functional impairment.
Chinese version of the School Bullying Experience Questionnaire (C-SBEQ)
The self-report C-SBEQ was used to evaluate participants’ involvement in school bullying in the previous year with 16 items answered on a 4-point Likert-type scale (Kim, Koh, & Noh, 2001; Yen, Kim, Tang, Wu, & Cheng, 2012).This scale is composed of four 4-item subscales evaluating whether the participant has been a victim of verbal or relational bullying (Items 1-4, including social exclusion, being called a mean nickname, and being spoken ill of), a victim of physical bullying (Items 5-8, including being beaten up, being forced to do work, and having money, school supplies, and snacks taken away), a perpetrator of verbal and relational bullying (Items 9-12), or a perpetrator of physical bullying (Items 13-16). Participants who answered 2 or 3 on any item among Items 1 to 4, 5 to 8, 9 to 12, and 13 to 16 were identified as self-reported victims of verbal and relational bullying, victims of physical bullying, perpetrators of verbal and relational bullying, and perpetrators of physical bullying, respectively. The results of a previous study examining the psychometrics of the C-SBEQ have been described elsewhere and supported the reliability and validity of the questionnaire (Yen et al., 2012).
Children’s Depression Inventory–Taiwanese version (CDI-TW)
The self-reported CDI-TW consists of 27 items assessing the severity of depressive symptoms in the month preceding the study among children and adolescents (Chen, 2008; Kovacs, 1992). Participants rate themselves on the basis of how they feel and think, with each statement being rated from 0 to 2 (Chen, 2008; Kovacs, 1992). A higher total score on the CDI-TW represents a more severe level of depressive symptoms. The psychometrics of the CDI-TW were examined in a previous study on Taiwanese youths (Chen, 2008). The Cronbach’s alpha for the CDI-TW in the present study was .83.
Taiwanese version of the Multidimensional Anxiety Scale for Children (MASC-T)
The self-report MASC-T consists of 39 items rated on a 4-point Likert-type scale (March, 1997; Yen, Yang, Wu, Hsu, & Cheng., 2010). A higher total score on the MASC-T represents a more severe level of anxiety symptoms in the month preceding the study. The psychometrics of the MASC-T were examined in a past study on Taiwanese youths (Yen, Ko, Yen, & Cheng, 2008). The Cronbach’s alpha for the MASC-T in the present study was .88.
Athens Insomnia Scale (AIS)
We used the Taiwanese version of the eight-item AIS (AIS-8) to assess the severity of subjective insomnia in the month preceding the study (Soldatos, Dikeos, & Paparrigopoulos, 2000; Yen et al., 2008). Higher total scores indicate more severe insomnia symptoms and subjective sleep-related distress. The psychometrics of the Taiwanese version of the AIS-8 have been described elsewhere (Yen et al., 2008). The Cronbach’s alpha for the AIS-8 in the present study was .77.
ADHD symptoms
The subscales of Inattention and Hyperactivity–Impulsivity on the shortened Chinese version of the SNAP-IV were used to assess the severity of core Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; APA, 1994)–derived ADHD in the month preceding the study (Gau et al., 2008; Swanson et al., 2001). Each item was rated on a 4-point Likert-type scale from 0 (not at all) to 3 (very much). The Cronbach’s alphas of the Inattention and Hyperactivity–Impulsivity subscales in this study were .86 and .90, respectively.
Procedure and Statistical Analysis
Research assistants performed interviews by using the research questionnaires to collect data from the children and adolescents. Parents completed the shortened Chinese version of the SNAP-IV. Data analysis was performed using SPSS 20.0 statistical software (SPSS Inc., Chicago, IL, USA). We used logistic regression analysis models to examine the association of bullying involvement with pain and pain-induced functional impairment by controlling for the effects of demographic characteristics and ADHD symptoms. We also used multiple regression analysis models to examine the association of pain and pain-induced functional impairment with depression symptoms, anxiety symptoms, and poor sleep quality after controlling for the effects of demographic characteristics, ADHD symptoms, and bullying involvement. The odds ratio (OR) and the 95% confidence interval (CI) of the OR were used to represent the significance of the logistic regression analysis. A two-tailed p value of less than .05 was considered statistically significant in multiple regression analysis.
Results
Participants’ demographic, ADHD and pain characteristics, experiences of bullying involvement, and severity of depression and anxiety symptoms and poor sleep quality are shown in Table 1. Among the participants, 378 (79.7%) were boys and 96 (20.3%) were girls. The mean age was 11.0 years (SD = 2.8 years). According to the definition provided in the “Methods” section, 138 (29.1%) participants experienced significant pain, 59 (12.4%) reported pain-induced functional impairment, and 50 (10.5%) reported significant pain with pain-induced functional impairment.
Demographics, ADHD Symptoms, Pain Characteristics, Bullying Involvement, and Mental Health Problems (N = 474).
Note. SNAP-IV = Swanson, Nolan, and Pelham, Version IV Scale; CDI-TW = Children’s Depression Index–Taiwanese version; MASC-T = Taiwanese version of the Multidimensional Anxiety Scale for Children; AIS = Athens Insomnia Scale.
The results of logistic regression analysis examining the association of bullying involvement with pain are shown in Table 2. The results revealed that after controlling for the effects of demographic and ADHD characteristics, both victims of verbal and relational bullying (OR = 2.411, 95% CI = [1.495, 3.887]) and victims of physical bullying (OR = 2.341, 95% CI = [1.289, 4.250]) were more likely than nonvictims to experience significant pain. Both victims of verbal and relational bullying (OR = 3.060, 95% CI = [1.633, 5.732]) and victims of physical bullying (OR = 2.127, 95% CI = [1.061, 4.263]) were also more likely to experience pain-induced functional impairment. In addition, perpetrators of verbal and relational bullying were more likely than nonperpetrators to report significant pain (OR = 2.359, 95% CI = [1.378, 4.038]).
Association Between Bullying Involvement and Pain.
Note. OR = odds ratio; CI = confidence interval.
Compared with those with significant pain without dysfunction.
The results of multiple regression analysis on the association of pain with depression, anxiety, and poor sleep quality are shown in Tables 3 to 5. The results indicated that those with significant pain reported more severe depression (p < .001) and anxiety (p < .001) and worse sleep quality (p < .001) than did those without significant pain. Those with pain-induced functional impairment experienced more severe depression (p < .001) and anxiety (p < .001) and worse sleep quality (p < .001) than those without pain-induced functional impairment did. Compared with those who experienced significant pain but no pain-induced functional impairment, those who experienced both significant pain and pain-induced functional impairment reported worse sleep quality (p = .004) and tended to have more severe depression (p = .052).
Association Between Pain and Depression.
Compared with those with significant pain but without pain-induced functional impairment.
Association Between Pain and Anxiety.
Compared with those with significant pain but without pain-induced functional impairment.
Association Between Pain and Poor Sleep Quality.
Compared with those with significant pain but without pain-induced functional impairment.
Discussion
The results of the present study showed that compared with participants with ADHD who did not report being bullied, participants with ADHD who were the victims of verbal and relational bullying and physical bullying were more likely to report significant pain and pain-induced functional impairment. Several mechanisms may account for the association between bullying victimization and pain in youths with ADHD. First, physical bullying may directly result in the physical pain symptoms of victims. However, this direct mechanism cannot be applied to victims of verbal and relational bullying. Second, animal studies have found that chronic social defeat may alter the functioning of the dopaminergic system (Novick et al., 2015; Novick, Forster, Tejani-Butt, & Watt, 2011). Dopaminergic system dysfunction was hypothesized to partially account for the overlap between ADHD and pain problems (Paolino et al., 2015). Third, according to the transactional model of coping (Lazarus & Folkman, 1984), the experience of bullying victimization is a potential cause of stress that may involve evaluations of whether the event is threatening. If victims consider their coping abilities and resources to be insufficient, they may develop responses that are emotional (such as depression and anxiety), behavioral (such as avoidance), cognitive (such as a negative self-attitude), and physiological (such as heightened muscle tone). Research found that markedly heightened muscle tone resulting from autonomic dysfunction is associated with pain in children with ADHD (Stray et al., 2009). Clinical and educational professionals should be aware of the possibility that youths may be bullied when pain complaints are presented.
The results of previous studies on the association between bullying perpetration and pain in youths have been mixed. Some studies have found that bullying perpetrators were more likely to report pain than those who did not perpetrate bullying (Fekkes, Pijpers, & Verloove-Vanhorick, 2004; Kaltiala-Heino, Rimpelä, Rantanen, & Rimpelä, 2000), whereas some studies did not find a significant association between bullying perpetration and pain (Gini, 2008; Natvig, Albrektsen, & Qvarnstrøm, 2001). Notably, the present study found that perpetration of verbal and relational bullying, but not perpetration of physical bullying, was significantly associated with pain in children and adolescents with ADHD. The results of the present study may partially explain the heterogeneity of the results of previous studies. Prior research has also demonstrated that the perpetrators of verbal and relational bullying reported more severe symptoms of physical anxiety than did nonperpetrators of verbal and relational bullying, whereas no difference in these symptoms was found between perpetrators and nonperpetrators of physical bullying (Yen et al., 2013). The results of both the present and previous studies should remind mental health and educational professionals of the different relationships that exist among various types of bullying perpetration and pain in children and adolescents with ADHD.
The present study found that after control for bullying involvement, pain and pain-induced functional impairment had independent associations with depression, anxiety, and poor sleep quality in children and adolescents with ADHD. A review of the empirical results of epidemiological studies also showed that pain was as strongly associated with anxiety as it was with depressive disorders and that the extent to which pain interfered with activities was one of the strongest predictors for depression (Von Korff & Simon, 1996). This study also showed that certain psychological symptoms (low energy, disturbed sleep, worrying) were prominent among patients experiencing pain, while others (guilt, loneliness) were not (Von Korff & Simon, 1996). In addition, chronic pain and depression have been proposed to share common biological pathways and neurotransmitters. For example, mesolimbic dopamine system dysregulation may be associated with both pain and depression (Finan & Smith, 2013). Research has also supported the presence of depression and pain dysfunction early in the natural history of pain, as well as the conclusion that depression may persist as pain-related dysfunction becomes chronic (Von Korff & Simon, 1996). Although this cross-sectional study did not determine the causal relationships of pain and pain-related dysfunction with mental health problems, the results of the present study demonstrate the necessity for clinicians to evaluate mood and sleep problems among children and adolescents who have been diagnosed with ADHD and experience pain.
Compared with those who had significant pain but no pain-induced functional impairment, participants who reported both significant pain and pain-induced functional impairment had worse sleep quality (p = .004) and tended to exhibit more severe depression (p = .052). The results indicated that clinicians must routinely assess not only the location and severity of pain but also the subjective functional impairment caused by pain among children and adolescents with ADHD.
This study is one of the first to examine the relationships of pain and pain-induced functional impairment with various types of bullying involvement, as well as the relationships between pain and mental health problems after controlling for bullying involvement among children and adolescents with ADHD. However, our investigation had several limitations that deserve attention. First, the cross-sectional research design of this study limited our ability to draw conclusions regarding the causal relationships of pain with bullying involvement and mental health problems. Second, the data were provided by the children and adolescents themselves. The problem of shared-method variance resulting from reliance on a single source of information requires careful consideration. Third, the time span varied among the measuring scales. For example, the experience of bullying involvement was measured during the previous year, whereas pain and mental health problems were assessed during the previous month. The discrepancy in the time span among the measurements may weaken the reliability of inferences related to pain, bullying involvement, and mental health problems. Last, the present study was based on a sample of children and adolescents with ADHD in psychiatric outpatient clinics. The results of the present study might not be applicable to youths who have been diagnosed with ADHD and have not received clinical services.
Conclusion
When managing pain problems among children and adolescents with ADHD, clinical and educational professionals should consider the possibility of patient involvement in bullying, depression, anxiety, and poor sleep quality, and subsequently provide psychological and pharmacological interventions to ameliorate depression and anxiety. Routine assessment of pain, pain-related dysfunction, and involvement in bullying might be beneficial for further understanding the mental health status of children and adolescents with ADHD.
Footnotes
Authors’ Note
Yi-Chun Yeh and Mei-Feng Huang contributed equally to this study.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was supported by Grant NSC 99-2314-B-037-028-MY2 awarded by the National Science Council, Taiwan (ROC).
