Living environment can influence the effect of antidepressants


Antidepressants are drugs used to treat major depression and other conditions, including anxiety, obsessive compulsive disorder, eating disorder, and chronic pain.

Currently, the most common antidepressants are selective serotonin reuptake inhibitors (SSRIs, the best known is Prozactm). The drug influences mood by changing immune functions.

However, the effects of SSRIs on depression are contradictory. Sometimes, the drugs do not work in patients. In a recent study, scientists report that living environment can strongly change the drugs’ effect. The finding is published in Brain, Behavior, and Immunity.

Researchers from University of Modena and Reggio Emilia in Italy, University of Rome, Institut du Cerveau et de la Moelle épinière in France, Centre de recherche du CHU de Québec in Canada, University of Zurich, and Sapienza University of Rome conducted the study.

They first exposed mice to chronic stress to induce a depression-like symptom, and then treated the mice with SSRIs while putting them in either an enriched or a stressful condition.

In the enriched living condition, the mouse shelters had various colors and shapes. In the stressful living condition, there were several stressors, such as no shelter, new social groups, hard to get water, etc.

At the end of treatment (21 days), researchers measured the effects of SSRIs on the depression symptom.

They found that the drug effects were dependent on the quality of living environment. In the enriched condition, mice showed an increase in the expression of pro-inflammatory cytokines and decreased anti-inflammatory-related genes, as well as less signs of depression.

On the other hand, in the stressful condition, mice showed the opposite effect and more sings of depression.

This finding suggests that to cure depression, antidepressants may not be enough. Living environment can change the response to antidepressants and influence recovery.

A comfortable environment may enhance the drug effects and help patients recover from depression, but a stressful environment may reduce the drug effects and maintain the depression symptoms.

Citation: Alboni S, et al. (2016). Fluoxetine treatment affects the inflammatory response and microglial function according to the quality of the living environment. Brain, Behavior, and Immunity, published online. doi: 10.1016/j.bbi.2016.07.155.
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