There is an extensive literature on the link between psychosis and substance use. The nature of this association has been a matter of controversy for the last 2 decades, especially the possible cause effect relationship that may be involved in this association. The differential diagnosis of substance-induced psychotic disorder and primary psychotic disorder is particularly challenging during an acute admission when psychotic symptoms are the most severe and the identification of possible markers of these disorders could simplify their recognition and treatment.
The main objective of the current study was to compare the clinical picture between a sample of patients with substance-induced psychosis (SIP) and patients with primary psychosis, as regards the phenomenological aspects and to study the different correlates affecting their clinical picture.
Materials and Methods:
A comparative cross-sectional study including 22 patients with first-episode psychotic disorder recruited from the inpatient wards of the Institute of Psychiatry Ain-Shams University. All patients were interviewed between 1 week and 1 month of onset of symptoms using Structured Clinical Interview for DSM-IV (SCID-I) and Positive and Negative Syndrome Scale (PANSS). Patients were labeled into 2 groups according to diagnosis, group I: patients fulfilling criteria of brief psychotic episode. Group II: patients fulfilling criteria of substance-induced psychotic disorder.
No statistical difference between the 2 studied groups as regard PANSS score positive, negative, and general psychopathology, as well as the severity of symptoms. However, further analysis of the PANSS score components showed SIP group to have significantly higher P4 (excitement) score (P=0.02), G10 (disorientation) score (P=0.03), and G11 (poor attention) score (P=0.004).
This study adds to a growing body of literature highlighting the differences between SIP and primary psychosis. It provides set of variables that distinguish the substance-induced and primary psychosis groups from one another, which should be an area for further studies.