EPA-0281 – Life Time Diagnosis of Cannabis Abuse Affects Psychopathology of First-episode Schizophrenia

Abstract

Introduction:

There is no doubt that cannabis abuse contributes to the development of schizophrenia. However, the influence of cannabis on schizophrenia psychopathology remains unclear.

Aim of the study:

This study aimed at investigating the association between life time diagnosis of cannabis abuse (LTCA) and psychopathological manifestation of first-episode schizophrenia (FES).

Methods:

We recruited 45 FES patients. Schizophrenia was diagnosed based on DSM-IV and ICD-10 criteria, and confirmed using Operational Criteria for Psychotic Illness (OPCRIT). Additionally, all patients were assessed using Positive and Negative Syndrome Scale (PANSS). Patients with drug and/or alcohol abuse within one year of onset of psychotic symptoms were excluded.

Results:

Assessment with OPCRIT revealed that LTCA is associated with longer duration of excessive (p = 0.044) and reckless activity (p = 0.023), reduced need for sleep (p = 0.023), other primary delusions (p = 0.046), as well as thought withdrawal (p = 0.01) and thought broadcast (0.01). There was no significant difference in the total score of PANSS subscales (i.e. positive, negative and general). However, FES patients with LTCA experienced significantly more severe excitement (p = 0.031) and grandiosity (p = 0.018), as well as poorer impulse control (p = 0.008).

Conclusions:

Our results indicate that LTCA has a differential influence on psychopathology of FES exacerbating delusions of thought broadcast and withdrawal, affective symptoms and behavioural manifestation of experienced psychotic symptoms.