Cannabis use in children and adolescents with first episode psychosis: Influence on psychopathology and short-term outcome (CAFEPS study)

Abstract 

Objective

To know the prevalence of substance use and its relationship with psychopathology at onset and after six months in children and adolescents with first episode psychosis (FEP).

Method

110 FEP patients, aged 9–17, were assessed for substance use, and with the Positive and Negative Syndrome Scale (PANSS) and other psychopathological and general functioning scales at baseline and after a six-month follow-up.

Results

Patients' substance use at baseline was: tobacco (30.9%), cannabis (29.1%), alcohol (21.8%), cocaine (8.2%), amphetamines (2.7%), LSD (1.8%) and opiates (0.90%). Six months later, there was a decrease in patients' use of cannabis (p=0.004) and other drugs, except tobacco. Patients were divided, according to their baseline cannabis use, into 32 cannabis users (CU) and 78 non-cannabis users (NCU). CU were older (p=0.002) and had higher PANSS positive scores (p=0.002) and lower PANSS negative (p<0.001), PANSS general (p=0.002) and PANSS total (p=0.007) scores than NCU. At six months, CU had significantly lower PANSS positive (p=0.010), negative (p=0.0001), general (p=0.002) and total (p=0.002) scores than NCU. When we divided CU at six months into previous CU (n=16) and current CU (n=15), previous CU had the best outcome, NCU the worst and current CU had an intermediate profile.

Conclusions

Cannabis use may be related to higher positive symptom scores for FEP patients, with greater improvement after six months for those who cease using cannabis.

Keywords: Cannabis use, First episode psychosis, Substance use, Children and adolescents, Outcome