Does alcohol consumption influence the risk of depression? A recent meta-analysis1, published in the scientific journal Addiction, finds a J-shaped relation: low alcohol consumption is associated with a lower risk of depression, and with high alcohol consumption the risk increases, although insignificantly. But the risk of depression increases by almost 60% for people with alcohol use disorder.
What is already known? The relation between alcohol consumption and depression is complex. Some studies find a lower risk of depression with moderate alcohol consumption2, while others find none3. Excessive alcohol consumption and heavy drinking often coexists with depression, but whether this is a causal relation remains unclear.
What does this study add? This meta-analysis only includes longitudinal studies, and makes a clear distinction between different levels of alcohol consumption and alcohol use disorder.
The meta-analysis includes 42 cohort studies, resulting in more than 338.000 participants.
Data show the well-known J-shape: light to moderate alcohol consumption is associated with a significant decreased risk of depression while heavy drinking does not lead to a significant increase of depressive symptoms compared to non-drinkers (see Figure).
Heavy drinking versus alcohol use disorder
The main focus of the article is whether there is a difference in risk of depressive symptoms between heavy drinking and having alcohol use disorder (AUD). For this meta-analysis, heavy alcohol consumption is defined as drinking more than 168 grams of alcohol per week, which are about 14 alcoholic consumptions. AUD goes beyond a high level of alcohol consumption. People with AUD crave alcohol and build up a tolerance to alcohol which means they have to drink more to get the same effect. They have a tendency to continue drinking, despite of the physical and psychosocial problems, and exhibit withdrawal symptoms when they stop drinking.
In this analysis, heavy drinking is not significantly associated with depressive symptoms after adjusting for potential confounders such as socioeconomic status – including income, employment, education and marital status – and lifestyle factors such as physical activity and drug abuse. The authors suggest that the association between heavy alcohol consumption and depressive symptoms is most probably attributed to the shared confounding factors instead of the alcohol itself.
However, for people with AUD there was still a 60% increased risk to develop depression due to alcohol consumption after adjusting for potential confounders. The added AUD characteristics beyond high alcohol consumption might contribute to this association.
About 265 million people suffer from depression world-wide and the WHO predicts that it will be the second leading cause of global burden of disease by 20304,5.
- Only cohort studies included
- Adjusted for many confounders
- Dose-response analysis
- Distinction between heavy alcohol consumption and AUD
- Not adjusted for sick-quitters (although studies were only included when patients with depression at baseline were excluded)
1 Li, J., Wang, H., Li, M., Shen, Q., Li, X., Zhang, Y., … & Peng, Y. (2019). Effect of Alcohol Use Disorders and Alcohol Intake on the Risk of Subsequent Depressive Symptoms: A Systematic Review and Meta‐Analysis of Cohort Studies. Addiction.
2 Gémes, K., Forsell, Y., Janszky, I., László, K. D., Lundin, A., Ponce de Leon, A., … & Moller, J. (2019). Moderate alcohol consumption and depression–a longitudinal population‐based study in Sweden. Acta Psychiatrica Scandinavica, 139(6), 526-535.
3 Boden, J. M., Foulds, J. A., & Horwood, L. J. (2016). Examination of a possible J-shaped relationship between alcohol consumption and internalizing disorders in a longitudinal birth cohort. Drug and alcohol dependence, 162, 88-91.
4 World Health Orgaization. Fact Sheet: Depression. Geraadpleegd op january 2020
5 Mathers, C. D., & Loncar, D. (2006). Projections of global mortality and burden of disease from 2002 to 2030. Plos med, 3(11), e442.