Differences in alcohol and cannabis use amongst substance use disorder patients with and without comorbid attention-deficit/hyperactivity disorder

BACKGROUND: Substance use disorders (SUDs) continue to be a public health problem. Attention-deficit/hyperactivity disorder (ADHD) is seen as a risk factor for SUD. Prevalence of alcohol and cannabis use amongst adults with SUD and comorbid ADHD impacts both disorders cognitively and behaviourally. AIM: Our study aimed to compare alcohol and cannabis use between treatment-seeking SUD patients with ADHD and SUD patients without ADHD symptomatology. SETTING: Various rehabilitation centres, including the South African National Council on Alcoholism and Drug Dependence (SANCA) Centres, and Private and Provincial Government Substance Abuse Treatment Centres. METHODS: A cross-sectional study of adults on drug rehabilitation was conducted. Data on socio-demographic information and alcohol and cannabis use from 185 post-detox inpatients were collected. Diagnoses were based on DSM-IV criteria. Attention-deficit/hyperactivity disorder diagnosis was confirmed by the Diagnostic-Interview for ADHD in Adults (DIVA 2.0). SUD+ADHD (n = 52) and SUD-ADHD (n = 128) groups were compared on alcohol and cannabis use as a function of gender. RESULTS: No significant differences in the use of alcohol between the SUD+ADHD and SUD-ADHD groups were found. However, the SUD+ADHD group showed increased cannabis consumption. Especially, the SUD+ADHD females showed an earlier age of onset of cannabis use than the SUD-ADHD females and revealed that they use cannabis for a longer period compared with the SUD-ADHD females and SUD+ADHD and SUD-ADHD males. CONCLUSION: The results revealed the relationship between ADHD and cannabis use, especially amongst females with ADHD and reinforce the need to consider ADHD in cannabis use SUD in clinical interventions.