Jon Spear,
Department of Psychiatry, University of Western Australia and Fremantle Hospital;
Deirdre Alderton,
Alma Street Centre, Fremantle Hospital, South Metropolitan Health Service, Perth, Australia:
Dexamphetamine may be prescribed for adult Attention Deficit Hyperactivity Disorder (ADHD) [1]. Adult ADHD is associated with mood disorders, anxiety disorders and substance use disorders [2]. Psychosis is considered a rare consequence of prescribed dexamphetamine use [1]. This view is inconsistent with our clinical experience; six patients with psychoses associated with prescribed dexamphetamine use were admitted to a public mental health hospital over a 3-month period.
Patient 1:
A 25-year-old man presented with depressed mood, suicidal thoughts, insomnia, weight loss and delusions. He had a history of alcohol abuse and was prescribed dexamphetamine 30 mg/day and doxepin 50 mg/day by a private psychiatrist for ADHD and depressive disorder. On admission he was given the diagnosis of first episode psychosis.
Patient 2:
A 22-year-old man presented with loosening of associations, thought disorder and impaired judgement. He was taking dexamphetamine prescribed by a private psychiatrist for ADHD. The treating team made a diagnosis of disorganized schizophrenia.
Patient 3:
An 18-year-old woman presented with agitation, visual and auditory hallucinations, incoherent speech and disorientation. She was taking dexamphetamine 50 mg/day prescribed concurrently by two private psychiatrists. She had a family history of bipolar disorder. She was given the diagnosis of dexamphetamineinduced psychosis.
Patient 4:
A 25-year-old woman presented twice with verbal abuse, homicidal threats and auditory hallucinations. She was taking dexamphetamine prescribed by a private psychiatrist. She had abused amphetamines as a teenager and had a previous diagnosis of personality disorder. She was diagnosed with brief psychotic episode for the first admission and drug-induced psychosis for the second.
Patient 5:
A 41-year-old man presented with aggressive behaviour, labile mood, irritability, delusions and agitation. He was taking dexamphetamine 40 mg/day prescribed by a private psychiatrist. He had a past history of intravenous drug use and cannabis use. On admission he was diagnosed with hypomania.
Patient 6:
A 37-year-old man presented with selfneglect, reduced volition, insomnia, poor concentration and suicidal thoughts. He was taking dexamphetamine for ADHD, prescribed after he separated from his wife. He was noted to have avoidant personality traits and was initially diagnosed with drug-induced psychosis although this was later changed to adjustment disorder.
All the patients, except patient 2, improved within days of ceasing dexamphetamine and commencing antipsychotic medication. This case series is not able to demonstrate a causal association between prescribed dexamphetamine and psychotic disorder, but does highlight the need for caution when considering dexamphetamine for patients with a history of psychosis, bipolar disorder, personality disorder or substance use.
