Adolescents who use marijuana have significant differences in orbitofrontal cortex (OFC) connectivity associated with mood and anxiety compared with adolescents with no marijuana use, according to research published in the Journal of Affective Disorders.
Marijuana usage is increasing in adolescents, and the rate of comorbidity with mood and anxiety disorders is high. These findings may aid in identifying adolescents who are potentially at risk.
The study enrolled 43 marijuana-using and 31 non-using adolescents who completed the Hamilton Anxiety Scale (HAM-A) and Hamilton Depression Rating Scale (HAM-D) and underwent resting-state a functional magnetic resonance imaging (fMRI) scan.
Marijuana users exhibited increased depressive symptoms associated with increased connectivity between the left OFC and left parietal regions. Lower anxiety ratings were associated with increased connectivity between the right and left OFC and the right occipital and temporal regions. The results shed light on the neural correlatives that modulate the relationship between comorbid marijuana use and mood disorders, potentially aiding in the development of preventative and treatment measures.
Because the rates of comorbidity between mood and anxiety disorders and substance abuse are high, the clinical implications of these findings are significant. “The current study provides a preliminary framework toward identifying potential biomarkers such as OFC connectivity using neuroimaging techniques that could be targeted for early identification of individuals at risk for mood and substance use disorders,” The researchers noted. They additionally suggest the use of HAM-A and HAM-D in clinical practice to gain additional insight into possible vulnerabilities.
The study was limited by the disproportionate number of male participants. Researchers noted that future research should address potential sex differences in connectivity patterns related to depression and anxiety symptoms.
Subramaniam P, Rogowska J, DiMuzio J, et al. Orbitofrontal connectivity is associated with depression and anxiety in marijuana-using adolescents. Journal of Affective Disorders. 2018;239:234-241.