The hypothetical links between depression and substance-use disorder

Several lines of evidence have shown that patients with depression have higher rates of substance-use disorders than the general population^1,2

The presence of a major depressive episode increases the risk of drug dependence by 4.3 times,³ however, the relationship between substance-use disorder and MDD is bidirectional⁴

One meta-analysis, including 48 studies and 348,550 people, found a prevalence of substance-use disorder in men with MDD of 36%, and in women of 19%⁵

In an analysis of the STAR*D study data, patients with MDD and comorbid substance-use disorder were more likely to:^{6 6}

• Have earlier onset of depression
• Experience greater depressive symptomatology
• Experience greater functional impairment
• Have a greater suicide risk

MDD=major depressive disorder; STAR*D=Sequenced Treatment Alternatives to Relieve Depression