Profiles and mental health correlates of alcohol and illicit drug use in the Canadian population: an exploration of the J-curve hypothesis.

OBJECTIVE: Alcohol and (or) illicit drug use (AIDU) problems are associated with mental health difficulties, but low-to-moderate alcohol consumption may have mental health benefits, compared with abstinence. Our study aimed to explore the hypothesis of a nonlinear, or J-curve, relation between AIDU profiles and psychological distress, psychiatric disorders, and mental health service use in the general Canadian population.

METHODS: Data were collected from a representative sample of the Canadian population (n = 36 984). Multiple correspondence analyses and cluster analyses were used to extract AIDU profiles. Sociodemographics, psychological distress, psychiatric disorders, and mental health service use were assessed and compared between profiles.

RESULTS: Seven AIDU profiles emerged, including 3 involving risky or problematic AIDU that correlate with major affective disorders, anxiety disorders, suicidal behaviours, and higher levels of psychological distress. No J-curve relation was found for psychiatric disorders and mental health service use. The lifetime-abstainer profile correlates with the lowest rates of psychiatric disorders and mental health service use. Lifetime abstainers are also more often female, immigrant, and unemployed. Compared with other profiles, spirituality is more important in their life.

CONCLUSIONS: The hypothesis of a nonlinear relation between psychiatric disorders and AIDU was not supported. Lifetime AIDU abstainers have specific sociodemographic and cultural background characteristics in Canada.