Age, comorbid SUDs modify mental health risks linked to cannabis use disorder

Mental health risks associated with cannabis use disorder (CUD) differ by age and comorbid substance use disorders (SUDs), suggests a study.

A team of investigators used the TriNetX Research Network to identify patients with SUDs and no preceding mental disorders. They also compared adult patients with CUD only vs those with other SUDs, paediatric patients with CUD only vs those with other SUDs, and adult patients with CUD plus another SUD vs those with comorbid noncannabis SUDs.

The investigators then performed propensity score matching on demographic characteristics and 24 risk factors or comorbidities, as well as assessed the subsequent diagnosis of schizophrenia and other common mental disorders.

Adults with noncomorbid CUD, compared with individuals with other SUDs, showed a lower risk of schizophrenia (0.34 percent vs 0.42 percent; relative risk [RR], 0.81, 95 percent confidence interval [CI], 0.75‒0.88), depression (1.35 percent vs 1.74 percent; RR, 0.78, 95 percent CI, 0.75‒0.81), and psychotic disorders (0.36 percent vs 0.52 percent; RR, 0.68, 95 percent CI, 0.63‒0.73).

Individuals with CUD, compared with paediatric patients with other SUDs, were at greater risk of schizophrenia (0.29 percent vs 0.19 percent; RR, 1.52, 95 percent CI, 1.06‒2.19), depression (1.65 percent vs 1.27 percent; RR, 1.30, 95 percent CI, 1.13‒1.51), and anxiety disorders (8.13 percent vs 6.71 percent; RR, 1.21, 95 percent CI, 1.14‒1.29).

Finally, patients with CUD and a comorbid SUD had a lower risk of schizophrenia (1.94 percent vs 2.25 percent; RR, 0.86, 95 percent CI, 0.83‒0.90), depression (3.98 percent vs 5.67 percent; RR, 0.70, 95 percent CI, 0.68‒0.72), bipolar disorder (4.23 percent vs 5.60 percent; RR, 0.76, 95 percent CI, 0.74‒0.78), and anxiety disorders (16.20 percent vs 21.36 percent; RR, 0.76, 95 percent CI, 0.75‒0.77) than adult patients with other SUDs.

“CUD-associated mental health risks varied by age and comorbid SUDs, possibly due to earlier onset of mental disorders in cannabis users or age-related differences in CUD effects,” the investigators said.