High-fat diet may cause changes in the brain that lead to anxiety and depression

A new study in mice reveals that increased body weight and high blood sugar as a result of consuming a high-fat diet may cause anxiety and depressive symptoms and measurable changes in the brain.

Also, the beneficial effects of an antidepressant were blunted in mice fed a high-fat diet. "When treating depression, in general there is no predictor of treatment resistance," said Dr. Bruno Guiard, senior author of the British Journal of Pharmacology study. "So if we consider metabolic disorders as a putative treatment resistance predictor, this should encourage psychiatrists to put in place a personalized treatment with antidepressant drugs that do not further destabilize metabolism."

On the other hand, taking mice off a high-fat diet completely reversed the animals' metabolic impairments and lessened their anxious symptoms. "This finding reinforcing the idea that the normalization of metabolic parameters may give a better chance of achieving remission, particularly in depressed patients with type 2 diabetes," said Dr. Guiard.

The results set the tone for future investigations on potential mechanisms that may link metabolic and psychiatric disorders.