A self-determination theory perspective of motivations for cannabis-related harm reduction behaviours: evaluation of an expanded and adapted Treatment Self-Regulation Questionnaire.

OBJECTIVE

We sought to evaluate an expanded and adapted version of the Treatment Self-Regulation Questionnaire (TSRQ) to assess the internalization continuum of motivation per self-determination theory (SDT) for responsible cannabis use and cannabis protective behavioural strategies (PBS).

METHODS AND MEASURES

We recruited 1,196 college students (Study 1) and 1,409 adults (Study 2) who reported past-month cannabis to complete online surveys; a random sample of 501 adults in Study 2 completed a follow-up survey one month later.

RESULTS

We found support for a 3-factor exploratory structural equation model of a 26-item TSRQ representing autonomous motivation, controlled motivation, and amotivation. Associations of the TSRQ with cannabis outcomes were consistent with SDT such that greater autonomous motivation was associated with more frequent cannabis PBS use (e.g. 'Limit use to weekends'). In contrast, greater controlled motivation and amotivation were associated with more negative cannabis-related consequences and more severe cannabis use. Differences emerged for instructions referencing responsible cannabis use versus cannabis PBS in Study 1.

CONCLUSIONS

The results support the use of the expanded and adapted TSRQ to assess motivations per SDT for cannabis harm reduction behaviours. These findings warrant replication and suggest that responsible cannabis use is conceptualized to be distinct from cannabis PBS.