Aims: The aim of the study was to investigate antipsychotic use and associated factors in persons with substance-induced psychosis (SIP) and compared them with persons with other first-episode psychosis (FEP).

Methods: Incident Swedish SIP cases (n = 7320) during 2006–2016 were identified from health care registers and matched 1:1 with persons with FEP (n = 7320) by age, gender, and calendar year of diagnosis. Prevalence of antipsychotic use was assessed as point prevalence every 6 months, from 3 years before until 3 years after the first diagnosis. Factors associated with antipsychotic use among SIP were analysed with multivariable logistic regression including information on sociodemographic and work-related background, including disability pension and sickness absence, SIP types, and psychiatric diagnoses.

Results: Among SIP and FEP, the prevalence of antipsychotic use was low before the first diagnosis (3%–7% in SIP, 8%–16% in FEP), peaked 6 months after the first diagnosis (23% in SIP, 54% in FEP) and stabilized after that. After 3 years of first diagnosis, 19% of persons with SIP and 45% of persons with FEP used antipsychotics. Antipsychotic use 1 year after diagnosis among SIP was associated with previous substance use disorder, depression, anxiety, and personality disorder diagnoses, being on disability pension or on long-term sickness absence (>90 days), and cannabis- or multi-substance-induced psychosis.

Conclusion: Patients with FEP were using more frequently antipsychotics compared to SIP except for long-acting antipsychotics substance-induced psychoses are considered to be short-lived, antipsychotic use after an incident SIP episode is relatively common, especially among those with cannabis- or multi-substance-induced psychoses. Previous psychiatric comorbidity and poorer ability to work seem to increase the odds of antipsychotic medication use.