A research report to meet the requirements of the master of medicine in psychiatry at the University of Cape Town

Swartz, Michelle

A research report to meet the requirements of the master of medicine in psychiatry at the University of Cape Town

Thesis / Dissertation

2025

Abstract

Background: Cannabis is the most widely used substance worldwide and its use is much higher amongst adolescents. However, adolescents are at higher risk of negative sequelae secondary to this use, including poorer developmental outcomes and the possible development of mental disorders. On 31 March 2017, the South African High Court ruled that cannabis use by an adult in a private dwelling should be decriminalized. Aim: The aim of this study is to determine the clinical profile of adolescents who use cannabis, that present to a tertiary hospital in Cape Town, South Africa, before and after the high court ruling in 2017. Setting The study was conducted reviewing folders of adolescents admitted at Groote Schuur Hospital (GSH) in the Emergency Psychiatric Unit, Ward C23 in Cape Town, South Africa. Methods: This study was a retrospective folder review of adolescents admitted from April 2015 to March 2019. Results:The study included 266 participants and the total number of adolescents using cannabis admitted during the study period was 116. Cannabis use was the most commonly used substance in the study, with increased use seen post-ruling (n = 75; 65%). The most common frequency of cannabis use reported was daily use (n = 43; 57%). When comparing psychiatric diagnoses between cannabis users and non-cannabis users, a significantly higher proportion of patients who used cannabis pre-ruling had psychotic disorder (p < 0.001) and substance use disorder (p = 0.01). Post–ruling, the significance was p < 0.001 for psychotic and substance use disorders. The most common DSM-5 diagnoses in cannabis users pre-ruling were psychotic disorders (n = 27; 65.9%); post-ruling, it was psychotic disorders (n =36; 48%) and trauma and stressor-related disorders (n = 31; 41.3%). Conclusion: The study showed an increasing prevalence of cannabis use in adolescents admitted with mental illness after the high court ruling in 2017. This study also demonstrates that adolescents remain a vulnerable population to the effects of cannabis. This highlights the need for more focused adolescent interventions and services.