People who continue illegal substance use are much less likely to recover from first-episode psychosis
Stavanger, Norway - Research from Norway presented at this year’s International Early Psychosis Conference in Tokyo, Japan, shows that persistent and regular users of illegal substances (mostly cannabis or amphetamines or both) are far less likely to recover from a first episode of psychosis (FEP) than those who have stopped using or never used these drugs. The research, by Dr Melissa Weibell, Stavanger University Hospital and University of Stavanger, Norway, and colleagues, presents a strong argument against the legalisation of cannabis.
Little is known about the effect of different patterns of substance use on outcomes in FEP. This new study investigated different patterns of substance use in an epidemiological first-episode psychosis (FEP) sample, with the researchers predicting that persistent use would predict poorer outcomes compared to never users or users that had stopped.
The study included 301 patients aged 16-65 with first episode non-affective psychosis included (1997-2001) from three separate catchment areas in Norway and Denmark. Four patterns of substance use were defined; never used (153 patients), persistent use (43), completely stopped use having previously used (36), and on-off use (48) during the first 2-years of follow-up. 184 patients were followed up at 10 years and compared using symptom levels and remission status.
The researchers found patients who stopped using within the first two years of entering treatment had similar 10-year outcomes as patients who had never used with significantly lower symptom levels (including depressive symptoms) compared to patients with on-off or persistent use.
There was a trend for persistent users showing increasing negative symptoms over time. Importantly, there was a large and significant difference in remission rates, with 57% of never users and 63% of ‘stop’ users achieving remission at 10 years compared to 32% for on-off users and 34% for persistent users.
The authors say: “Our results show that substance use cessation in FEP is associated with similar outcomes to FEP patients who never used any substances; on-off use may be almost as detrimental to mental health as persistent use. The harmful effects of substance use in FEP can be substantially reduced if clinicians are able to assist patients to stop using altogether early on in the course of treatment.”
They add: “There are few longitudinal studies with long-term follow-up of FEP patients with regards to substance use, so this study is really exciting and has a strong and easy to follow clinical take-home message for FEP patients: stop using drugs early on and you will probably do better in the long-term. For clinicians, we need to focus on stopping use as early as possible and probably at the same time that we are treating the initial psychosis. This study also presents a strong argument against the legalisation of cannabis.”