This study is the first to assess preferences for cannabis-specific harm reduction interventions in people with EP who use cannabis. Results suggested that participants were more likely to choose an intervention if it: featured shorter sessions (e.g., 10 min), less frequent sessions (e.g., monthly), shorter intervention durations (e.g., 1 month) and was technology-based. Participants strongly preferred participating in a shorter booster (e.g., 1 month). Individual preference differences were identified, with women, gender-diverse people and people with higher education levels preferring technology-based interventions.

The findings from the DCEs and the non-DCE questionnaire were congruent, indicating a proclivity for shorter interventions. While patients preferred the briefest intervention options, it may be that interventions that effectively promote change may require more than a single 10-min session. Likewise, an intervention of low efficacy which integrates population preferences into its design may be moderately effective due to other factors (e.g., appeal, engagement). The evidence regarding optimal duration and its relationship to treatment efficacy remains unclear. There is evidence supporting long- over short-duration cannabis interventions (i.e., >4 sessions vs. <4 sessions) in people with CUD. ⁴⁰ Preliminary evidence supports brief psychosocial interventions (e.g., 7 weekly sessions) for people with psychosis on other clinical outcomes^41,42 and for brief cannabis-specific interventions (e.g., single session) in the general population. ⁴³ A review of MI interventions for individuals with dual diagnoses did not find an association between treatment length and efficacy for substance use. ⁴⁴ Our results raise the question of whether shorter interventions would translate into clinical benefits (e.g., efficacy/effectiveness), underscoring the need for thorough evaluation (including acceptability, feasibility and clinical effectiveness) before implementation. It also highlights the challenge of striking a careful balance between patient preferences (which may contribute to intervention acceptability) and what is recommended based on efficacy data.

This study highlighted a strong preference for technology-based harm reduction interventions, consistent with prior research indicating openness to technology-based services among people with EP.^34,45 The potential of technology-based interventions as an alternative to in-person interventions has been documented. ⁴⁶ Whether this translates to intervention adherence or efficiency remains to be studied. Considering the scarcity of cannabis-specific interventions, the challenge of engagement, and the potential for technology-based interventions to enhance well-being in individuals with EP, ⁴⁷ developing cannabis-focused, technology-based interventions offer an opportunity to enhance health services. While over 60 technology-based interventions exist for individuals with psychosis, none focus on managing cannabis use, and high-quality clinical trials evaluating efficacy are lacking. ⁴⁷ More research on technology-based interventions specifically addressing cannabis use and their implementation in clinical settings is needed.

Nearly half of the participants indicated their preferred primary goal for a harm reduction intervention as reducing use, rather than using cannabis in less harmful ways or avoiding risky cannabis-related situations. It is worth noting that half of our sample had a CUD but did not want CUD treatment, instead preferring harm reduction interventions. This seeming discrepancy is also documented in the MI literature, recognizing that a participant's motivation to change (e.g., their stage of change) may not directly translate into actionable change. Consequently, motivational interventions are recommended to bridge the gap between contemplation and commitment. ⁴⁸ Our findings underscore the pertinence of developing harm reduction interventions that meet participants at their stage of change, and that provide built-in flexibility regarding cannabis goals, including proposing diverse cannabis-related objectives. As the question on preferred primary goal was non-DCE data, another possible explanation may relate to social desirability bias: participants may have chosen the more “appropriate” response, which aligned with the commonly-emphasized goal in clinical care of cannabis cessation or reduction.

Previously, DCEs have been conducted to quantify preferences and identify segments of people expressing distinct preferences.^23,49 While not designed for this purpose, our results too suggest differences in preferences based on certain characteristics; future research could explore whether specific profiles correspond to particular preferences. DCE 1 suggested that technology-based interventions were specifically preferred by women and gender-diverse people; DCE 2 suggested education-based differences in preferences. The non-DCE questionnaire results suggested varied preferences for therapeutic approaches, with participants split between cognitive-behavioral therapy, MI and brief psychoeducation interventions. Another study also noted gender differences in technology use, finding women with EP more likely to use smartphones, while men preferred phones without internet. ⁵⁰ Collectively, findings of preference differences highlight the need for further research to explore factors influencing the receptiveness and effectiveness of harm reduction interventions among subgroups of participants and/or the need to offer diverse interventions to better personalize treatment.