Addiction Vulnerability: Exploring Relationships Among Cigarette Smoking, Substance Misuse, and Early Psychosis.

OBJECTIVE: Smoking rates in adolescents at risk for psychosis are significantly greater than in those who are not at risk. Recent research suggests that cigarette smoking in adolescence may be a potential marker of transition to psychosis, although the exact relationship between the two remains unclear. Our aim was to examine whether tobacco smoking is a potential marker of transition to psychosis or subsequent episodes of psychosis, independently of other substance use, or alternatively whether smoking is essentially a general marker of later mental illness episodes.

METHODS: This substudy was conducted as part of an audit of a specialized early psychosis community mental health service, the Psychological Assistance Service (PAS). A multilayered audit over 10 years (January 1997 to December 2007) of PAS presentations was conducted (N = 1997), which documented baseline sociodemographic and clinical characteristics and subsequent illness episodes and service usage. Among clients with baseline smoking status information (n = 421, mean age = 18.3 years), this study examined predictors of transition to or subsequent episodes of psychosis, substance misuse, and affective disorder.

RESULTS: A recent psychosis episode at baseline and receiving ongoing treatment from PAS predicted transition to or subsequent psychosis episodes; however, baseline ultra-high-risk status was not predictive. In addition, baseline smoking/substance misuse status was a significant predictor, with smokers being twice as likely to experience a subsequent episode of psychosis, even after controlling for other baseline comorbidity. Baseline smoking status also independently predicted subsequent substance misuse episodes, but not subsequent affective disorder. Among clients experiencing post-PAS comorbid substance misuse and psychosis, the majority (80.3%) reported smoking at baseline.

CONCLUSIONS: Smoking status at service presentation appeared to function as a general proxy for addiction vulnerability among young help seekers and thereby as a potential marker for the development of severe mental illness (including psychosis) and associated health problems. Routine evaluations of presenting problems need to incorporate comprehensive assessments of early substance misuse and tobacco smoking. Adjunctive lifestyle interventions promoting smoking cessation, physical health, and well-being need to be offered in conjunction with conventional mental health interventions tailored to key presenting problems, recovery, and psychological strengthening.