Characteristics and outcomes of young people with substance induced psychotic disorder

Substance induced psychotic disorders (SIPD) have been historically considered as associated with better clinical and functional outcomes than other psychotic diagnoses. As a result, treatments for those with SIPD are often considerably less intensive, yet this is not based on evidence. The present study aimed to examine whether differences exist between those with SIPD and other first episode psychosis (FEP) diagnoses in regards to demographic and clinical factors, and to determine the symptomatic, clinical and functional outcomes in those with SIPD.

This study included all young people aged 15-24 who presented with a FEP to the Early Psychosis Prevention and Intervention Centre between 01/01/2011 and 31/12/2013. Group differences were analysed with independent samples t-tests and chi-square analyses and equivalent non-parametric tests as appropriate. Where applicable, odds ratios were calculated.

544 young people presented with a FEP and 10.3% (N = 56) were diagnosed with SIPD. Individuals with SIPD were more likely to be male, unemployed, and have a comorbid substance use disorder. There were no significant differences between groups regarding duration of untreated psychosis, severity of psychotic symptoms, time to remission, or rates of relapse. Those with SIPD were less likely to be employed or engaged in study at discharge and 35.7% of those with SIPD had a change of diagnosis to a schizophrenia spectrum or bipolar disorder after a median of 84 weeks.

Young people diagnosed with SIPD should be an important focus of early intervention services and receive comparable treatment to those with other psychotic diagnoses.