Patients with first-episode psychosis (FEP) who also present with substance abuse have a higher rate of hospitalisation after 12 months than their peers who do not, an Italian study reports.
The difference remained significant even in patients who stop using substances after psychosis onset, the study researchers note.
“The identification of a ‘potentially modifiable’ environmental predictor of the course of the illness such as substance use at psychosis onset allows us to envisage the possibility of ameliorating the course of the illness by managing this factor,” say lead author Ilaria Tarricone (Bologna University) and colleagues.
They carried out a 12-month follow-up study of an incidence cohort of 163 patients who presented with FEP at one of three community mental health centres in Bologna between January 2002 and December 2009. Patients fell into four diagnostic groups: affective psychoses, non-affective psychoses, schizophrenia (including schizoaffective disorder) and substance-induced psychoses.
Tarricone and co-workers found that the 50 patients who used substances were significantly more likely to be hospitalised during follow-up than non-users, with 32 (64%) requiring hospitalisation compared with 27 (24%).
The odds of hospitalisation were 5.8 times greater for substance users, after adjusting for age, gender, being single and duration of untreated psychosis., factors which also significantly influenced the chance of compulsory hospitalisation.
And even if patients stopped using substances after the onset of FEP, they still had a significantly higher rate of hospitalisation compared with non-users, at 61% versus 24%.
Substance use was not only associated with an increased likelihood of hospitalisation, but also of compulsory hospitalisation, with rates of 35% versus 12% for non-users.
Male gender and being single were found to be associated with a higher rate of hospitalisations, and substance abuse seemed to affect particularly male, native Italian patients.
Writing in Schizophrenia Research, the researchers conclude: “The identification of potentially modifiable environmental predictors, such as substance use, on the course of the illness and of a specific group of patients who more frequently present this factor, such as native young men in Bologna, allows us to envisage a preventive approach to chronicity in psychotic disorders.”
This article first appeared on News Medical on 25 February, 2014.