Studies have shown many mood disorders, including depression may increase the risk of drug addiction. Evidence has also indicated the opposite, in that the use of drugs may lead to depression and increase the negative effects associated with stress. A study conducted by the chair of neuroscience, Eric J. Nestler of Mount Sinai School of Medicine in a recent report, found a link between drug abuse and depression.
The results according to the study show that when mice were given cocaine each day for a week to simulate chronic drug abuse similar to humans, the mice were more likely to display depressive behaviors as opposed to the mice that did not receive cocaine doses. The mice appeared to display depression symptoms following social stressful situation that involved an intimidating and aggressive mouse. The mice receiving the drugs became lethargic and showed reluctance to interact with other mice.
Reports from the study also show that the researchers found changes in the molecules of the nucleus accumbens, the region prone to depression and stress in mice. Although it is more difficult to conduct the same testing in humans, results did show that postpartum tissue of humans, who had been diagnosed with depression, also had defects in the nucleus accumbens. The findings from the study have provided clues as to the relationship between increased depression and drug abuse.