Understanding the role of cannabis in patients with suicidal ideation presenting to the emergency department: systematic chart review.

Background: The association between cannabis use and suicidality has been established, but details on impacts of legalisation, as well as long-term service use, have had limited attention.

Aims: To examine if changes are present in suicide presentations with access to legal cannabis.

Method: This study employed administrative database and medical record reviews to identify two cohorts of patients presenting with suicidal ideation/attempts and cannabis use to emergency departments, for two periods: 17 October 2018 to 30 April 2019, and 17 October 2020 to 30 April 2021. Demographic and clinical outcome data were obtained, and emergency department healthcare usage for 2 years before and 2 years after index encounter were compared, to further understand emergency department presentations for the same complaint.

Results: Number of emergency department encounters following the index visit and number of emergency department encounters specifically relating to suicidality following the index visit were significantly different between cohorts (t = 2.05, P = 0.042; t = 2.23, P = 0.027, respectively), with the immediate post-cannabis legalisation period demonstrating greater numbers of subsequent emergency department visits for suicidality. Additional associations were found between personality disorders and repeat emergency department visits related to cannabis use.

Conclusions: There appears to be stability in the patient profile of those presenting to the emergency department with a complaint relating to suicide while reporting cannabis use from the period directly following legalisation in Canada, to a similar time frame 2 years later despite reported increased use of cannabis in the general population over this period. Despite the rising potency and access to legal cannabis, suicide risk remains stable, although concerning.