Factor structure of the Cannabis Experiences Questionnaire in a first-episode psychosis sample.

AIM: The Cannabis Experiences Questionnaire (CEQ) was developed to measure the subjective experiences of cannabis use both during and after intoxication. Despite the need to better understand the nature of the complex and significant relationship between cannabis use and early psychosis, this questionnaire has rarely been used in individuals with first-episode psychosis. METHODS: We conducted a set of factor analyses using CEQ data from 194 first-episode psychosis patients who used cannabis in order to uncover the underlying factor structure of the questionnaire and thus the overarching types of psychological experiences during/after using cannabis in young people with psychotic disorders. RESULTS: Our exploratory factor analysis identified 4 subscales, including: Distortions of Reality and Self-Perception (Factor 1), Euphoria Effects (Factor 2), Slowing and Amotivational Effects (Factor 3), and Anxiety and Paranoia Effects (Factor 4). CONCLUSIONS: Elucidating the underlying factor structure of the CEQ in first-episode psychosis samples could help researchers move towards a deeper understanding of the types of experiences associated with cannabis intoxication among young adults with first-episode psychosis and could inform the development of programs designed to reduce use, improve the course of illness, and possibly delay or prevent the onset of psychotic symptoms in those at risk.

Development and validation of the cannabis experiences questionnaire - Intoxication effects checklist (CEQ-I) short form.

OBJECTIVE: To develop and validate a short form of the Cannabis Experiences Questionnaire - Intoxication Effects (CEQ-I), a 42-item scale which measures the euphoric and paranoid-dysphoric effects of cannabis intoxication. METHOD: Exploratory and confirmatory factor analyses were conducted among 604 past-month cannabis users to develop the short form. The factor structure was replicated in a second sample of 146 past-month cannabis users. The concurrent validity of the scale was also examined. RESULTS: Consistent with previous research, two factors were identified (paranoid-dysphoric; euphoric), and were replicated with confirmatory factor analyses. The most parsimonious scale consisted of 13 items. Correlations of short-form subscales with corresponding original subscales were high. The paranoid-dysphoric subscale was also moderately positively correlated with measures of psychotic-like experiences (PLEs) and psychological distress. CONCLUSIONS: The revised and validated CEQ-I short form can be used to explore the euphoric and paranoid-dysphoric effects of cannabis intoxication in young cannabis users, and whether these experiences increase their risk of developing cannabis use and psychotic disorders. The CEQ-I short form has the potential to aid in the identification of young cannabis users at risk of the paranoid-dysphoric effects of cannabis intoxication and may assist in the development of early intervention strategies targeting cannabis users with PLEs.