Alcohol dependence signs include an inability to stop drinking, failure to meet normal expectations due to drinking, and feeling a need to drink after a heavy session, as well as harmful effects such as drink-related memory loss.
The researchers found that people who appeared to be dependent on alcohol at age 18 (or at any age from 17 to 22) were more likely than their peers to have depression at age 24. Those with a score of zero on the alcohol dependence scale at age 18 face an 11% probability of depression by age 24, compared to 15% for those with a score of one on the scale (an increase from zero to one on the alcohol dependency scale represents a 28% increase in the probability of not being able to stop drinking once started and a 33% increase in the probability of failing to do what was normally expected of you). This relationship remained after they adjusted for potential confounding factors such as substance use and depressive symptoms at age 16, suggesting that there may be a causal relationship between alcohol dependence and subsequent depression that is not explained by poor overall mental health in adolescence.
The researchers found that consumption levels alone were not associated with an increased risk of depression, which they say may be partly due to the fact that drinking in late adolescence is often tied with social contact and reflects social norms. Problematic drinking patterns could be a warning sign of future mental health problems, so helping young people to avoid problematic alcohol use could have long-term benefits to their mental health.
Paper: ‘The association of alcohol dependence and consumption during adolescence with depression in young adulthood: a prospective cohort study in England’ by Gemma Hammerton, Gemma Lewis, Jon Heron, Gwen Fernandes, Matthew Hickman, Glyn Lewis in The Lancet Psychiatry