Source: Gut  |  Posted 10 years ago

More research is needed to identify characteristics of cannabis users that account for their higher risk of depression.

This study in Baltimore, Maryland, United States, sought to estimate the degree to which cannabis abuse is a risk factor for depressive symptoms rather than an effort to self-medicate depression.

Participants were 1,920 people from the 1980 Baltimore Epidemiologic Catchment Area (ECA) study who were reassessed between 1994 and 1996 as part of a follow-up study.

Researchers focused their analysis on two cohorts: 849 people who reported no depressive symptoms at baseline and another 1,837 people with no diagnosis of cannabis abuse at baseline.

Symptoms of depression, cannabis abuse and other psychiatric disorders were assessed via the Diagnostic Interview Schedule.

Among people with no baseline depressive symptoms, those with a baseline diagnosis of cannabis abuse were four times more likely than those with no baseline cannabis abuse to have depressive symptoms at the follow-up assessment.

This remained the case after researchers took into account such factors as age, gender, antisocial symptoms and other baseline covariates.

In particular, these subjects were more likely to have experienced suicidal ideation and anhedonia during the follow-up period.

Among those participants who had no diagnosis of cannabis abuse at baseline, baseline depressive symptoms did not significantly predict cannabis abuse at the follow-up assessment.

Further research is needed to identify characteristics of individuals who abuse cannabis that account for their higher risk of depression to estimate the degree of impairment resulting from their depression, these authors conclude.