cannabis

Cannabis Use in Adolescence Affects Later Mood, Mental Health

Escalating cannabis use in adolescent men was associated with negative functional connectivity linked to increased depression symptoms and low educational attainment in early adulthood, according to a recent study.

The study enrolled 158 young men from the Pitt Mother and Child Project who underwent functional magnetic resonance imaging and completed substance use data at 20 years of age. Latent class growth analysis was used to determine trajectories of cannabis use frequency from 14 to 19 years of age, and psychophysiological interaction analysis was used to measure functional connectivity between the nucleus accumbens (NAcc) and the prefrontal cortex (PFC). In addition, researchers evaluated the potential association between functional connectivity and depressive symptoms, anhedonia, and educational attainment at age 22.
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Participants were categorized based on trajectories of adolescent cannabis use as stable high, escalating, or stable low. The trajectory of cannabis use had a significant effect on NAcc functional connectivity to the medial PFC, with young men in the escalating trajectory group displaying a negative connectivity pattern between the NAcc and medial PFC. Negative functional connectivity was linked to higher levels of depressive symptoms, anhedonia, and lower education attainment at age 22.

“Pattern of cannabis use frequency across adolescence in US youth could have consequences for mood symptoms and educational attainment in early adulthood via altered function in neural reward circuitry,” the researchers concluded.1

“The findings highlight that understanding marijuana use across the entire period of adolescence, which we know is an extremely vulnerable developmental phase, may tell us much more about detrimental long-term impacts than knowing about overall or one time use.”2

—Melissa Weiss

Reference:

Lichenstein SD, Musselman S, Shaw DS, Sitnick S, Forbes EE. Nucleus accumbens functional connectivity at age 20 is associated with trajectory of adolescent cannabis use and predicts psychosocial functioning in young adulthood [published July 25, 2017]. Addiction. doi:10.1111/add.13882.