Drug induced psychosis

Clinical case scenario

You have a telephone consultation with the parents of a 19-year-old male, Ben, over his increasingly bizarre behaviour. He has no significant past mental health history. He has become more withdrawn and increasingly agitated in the last few weeks. You agree to do a home visit to review him.

During the visit it becomes apparent that he is suffering from delusions. Ben believes that he is being watched and under surveillance by his neighbours; he is afraid to leave his house and believes they are tracking him. Ben reports some intermittent auditory hallucinations and reveals he has been using cannabis to help keep him calm.

Given these features, you decide he needs further tests and organise an emergency psychiatric admission.

His parents are worried and ask you what is happening to Ben.

Psychosis

Psychosis is a complex multifactorial mental health condition that encompasses a variety of symptoms that distort an individual’s ability to interpret and perceive reality. This impacts day-to-day functioning, as well as affecting their thoughts, behaviours and feelings (NHS UK, 2019). Drug induced psychosis occurs either as a result of the drug’s direct chemical effect, or due to exacerbation of an underlying known or unknown mental health condition. As many of half of people with psychosis also have a substance use disorder, and thus determining cause and effect is challenging.

Symptoms

The presentation of psychosis can vary based on the underlying cause; however, key features include hallucinations, delusions and altered thought processes. Hallucinations are altered sensory perceptions of an auditory, tactile or a visual nature. Delusions are fixed irrational beliefs that persist despite the presence of contradictory evidence. These are out of line with the patient’s cultural or social beliefs and can include persecutory thoughts, jealously-related delusions, or grandiose beliefs.

Not all individuals will present with overt symptoms. In primary care, individuals may present with a slow onset of subtle features such as a decreased ability to function in life, poorer concentration, higher paranoia, or poor self-care. They may also present with worsening mood, social isolation or poor sleep. A family member may raise a concern, rather than the patient if they notice a decline in both the mental and physical state (Archinigas, 2015).

Pathophysiology

Dopamine is suspected to increase the activity within the limbic regions leading to mislabelling of stimuli, inducing hallucinations and creating altered sensory states. Many antipsychotics work by inhibiting or lowering the dopamine within the mesolimbic pathway (Ham et al., 2017).

Causes

Psychosis can arise due to a single event, such as acute drug use, or have multifactorial causes. Pre-existing mental health disorders are associated with psychotic episodes, in particular depression, bipolar disorder, schizophrenia, schizoaffective disorder and delusional disorder. There is a genetic component to psychosis risk; having a first-degree relative with a psychotic disorder increases an individual’s lifetime risk of developing psychosis from 1% to 10%. Adverse life events can also contribute, such as a recent bereavement or adverse childhood experiences.

Some medical conditions are associated with psychotic episodes. Examples include human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS), malaria, Alzheimer’s disease, Lewy-body dementia, encephalitis, Parkinson’s disease, systemic lupus erythematosus, Huntington’s disease, multiple sclerosis, Wilsons disease and certain cancers (Archinigas, 2015). Childbirth is also associated with an increased risk of psychosis. Postpartum psychosis affects up to 1/1000 women within the first 2 weeks of birth (NHS UK, 2019).

Drug induced psychosis

Drug induced psychosis presents with similar symptoms as described, but may also present with signs of drug ingestion, withdrawal, or dependency. These may also present with post use features of sleep disturbance, headaches, paranoia, hallucinations, confusion, memory issues, mood lability, anxiety and depression, which can make it hard to distinguish from the onset of a mental health disorder. Prescription medications that can cause psychosis include dopamine agonists (levodopa) as well as the cessation of dopamine antagonists such as aripiprazole. Other causes include opioids steroids, antiepileptic drugs, antimalarial drugs and antiretroviral medications. Medication-induced psychosis is rare. Drug-induced psychosis is typically associated with recreational drug use, and these drugs are outlined below. It is worth noting that although alcohol is not formally discussed within this article it can exacerbate the effects of recreational drugs.

Clinical case discussion (continued)

You take a detailed history from Ben and conduct a mental health examination.

You are concerned that Ben is displaying signs and symptoms of a psychotic episode and he lacks insight into his condition. You conduct a risk assessment and Ben says he would not hurt others but feels very overwhelmed when he is hearing voices and sometimes wants to hurt himself to make them stop.

You refer him urgently to the mental health crisis team. A psychiatrist confirms a provisional diagnosis of a psychotic episode and that this may be related to cannabis used. He is commenced on an antipsychotic medication, and once stable, is discharged for community follow up.

Ben’s parents are worried about long-term treatment and complications. They wish to discuss this with you.

Diagnosis

A detailed history and mental state examination are vital when a patient presents with possible psychosis. These are outlined in Box 1 and Box 2, respectively. Box 1.

History for psychosis - consider examples.

Useful questions to consider during the consultation:

What are the key features of this episode?

When did this episode start?

Are there any softer features of neglect?

 ○ Self-neglect

 ○ Poor sleep

 ○ Poor concentration

 ○ Increasing paranoia or social isolation

Are there any hallucinations present?

 ○ If so, auditory, visual, tactile: Are they threatening?

 ○ What do they say? What do they see?

Are there any delusions present?

Is the patient at risk to themselves or others?

 ○ Any history of self-harm or suicide attempts

     ○  Any current self-harm or suicidal attempts or thoughts?

 ○ If there any hallucinations or delusions, on which they may be compelled to act?

 ○ Any family or social support or triggers?

 ○ Are there any unintentional risks due to neglect or poor judgement?

 ○ Is there a safeguarding required?

 ○ Any risk to others, domestic violence?

Does the patient have insight?

Any substance misuse history?

 ○ What substance? Quantity? Frequency? When last ingested?

  ○ Route? Other drugs? Any alcohol?

  ○ Past historical use of drugs?

Past medical history and mental health history

Is there any family history of mental health?

Is there any other Medication used?

 ○ Any anticonvulsant, steroids, dopamine agonists?

Are there any recent psycho-social triggers?

 ○ Recent bereavement? Poor sleep?

     ○   Sexual abuse domestic violence – historical or present?

The history should review current and historic substance misuse, see Box 1. It is also important to consider psychosocial aspects that may have contributed to the episode such as domestic violence, sexual abuse or other psychosocial stressors. The history should incorporate an assessment of risk, including intent or awareness of any danger to themselves or others and any violent delusions.

A mental state examination is vital to establish diagnosis, to further assess risk and to determine whether the individual has capacity or not (National Institute for Health and Care Excellence (NICE) 2021). See Box 2 for further details.

Individuals with suspected psychosis need to have bloods, urine cultures, a urine drug screen and neuro imaging to exclude organic pathology that may be treatable or reversible. Suggested blood tests include a full blood count, urea and electrolytes, thyroid function tests, liver function tests and C reactive peptide, a HIV screen and syphilis screen may also be considered, as these conditions can present with neuropsychiatric features (NICE, 2021).

Management

In all cases of suspected psychosis there is a need for early referral to the early intervention in psychosis or crisis teams, depending on local service pathways.

Mental health teams organise a detailed assessment via an approved mental health professional to make an initial diagnosis, review if a psychiatrist is required and consider if detention is needed under the Mental Health Act. For those aged less than 18 years old, same-day referral to child and adolescent mental health services is required. Pregnant women or those considering a pregnancy with a history of psychosis should be managed in secondary care, given the risk of deterioration in pregnancy.

If inpatient treatment is required, voluntary admission is encouraged. If this not feasible or is refused, then admission can occur under the Mental Health Act under sections 2 and 4, as described in Box 3. Box 3.

Mental Health Act classification 1983.

This Act governs the compulsory admission, detention, and treatment of patients with suspected mental health conditions in their best interests.

Section 2. An assessment section to establish a diagnosis which requires two doctors and is applied for by AMHP. Lasting for 28 days it cannot be extended but may be converted to a section 3 for treatment.

Section 3. A treatment section which requires a known diagnosis in order for application and again requires two doctors. Lasting for 6 months initially but can be extended for another 6 months.

Section 4. An emergency admission section only used within hospital wards while waiting for a section 2 to be applied for and lasts only 72 hours

Section 5. An emergency admission section only used by a nurse within hospital wards while waiting for a doctor and allows detention for a maximum of 6 hours only

Section 135. This enables the police to enter a patient’s home and take them to a place of safety for assessment within a 24 hour period. It needs a warrant which is applied for by approved mental health professional (AMPH).

Section 136. This enables police to take a patient to a place of safety (hospital, care home or a police station) from anywhere outside of the house. It does not require a warrant, but does need a doctor and AMPH and lasts for 24 hours again.

It is important to tell individuals that they must not drive during an acute episode of psychosis and must notify the Driver and Vehicle Licensing Agency (DVLA) about their illness (NICE, 2021).

Long-term complications and challenges for GPs

Individuals with episodes of psychosis are associated with increasing rates of suicide and self-harm, as well as an increased risk of further relapses of both the psychosis and of any associated substance abuse. They are also at a higher risk of violence during these episodes and safeguarding must always be assessed, particularly, if there are any children or other vulnerable adults present within the family structure.

Given mental health incidence is increasing and contributing towards a large proportion of primary care workload, it is important to be able to place these individuals on the appropriate registers for regular reviews and to consider the impact on their carers and family members. It is also worth setting up additional searches on the practice register to check for compliance with medication and attendance for health reviews.

Key points