Damping down depression

Reducing the brain levels of ceramide-a fatty acid molecule found in the body-has an antidepressant effect in mouse models of the disease, reports a study published online this week in Nature Medicine.The findings suggest a potential new therapeutic approach to more effectively treating depression in humans.

Ceramide is a molecule released when an enzyme cleaves sphingomyelin, a lipid enriched in membranes of brain cells.

Erich Gulbins and colleagues found that mice exposed to stress had increased brain ceramide concentrations compared with non-stressed mice. Commonly used antidepressant drugs, such as amitriptyline and fluoxetine, normalized ceramide levels and reduced depressive behavior in treated mice. Furthermore, Gulbins and colleagues reported that injection of ceramide into the brain of normal mice, or overexpression of the enzyme that cleaves sphingomyelin, could induce depressive behaviors, whereas fendiline, an inhibitor of the enzyme, had antidepressant properties.