New research suggests that a high-fat diet may trigger anxiety and depression.

A new study in mice suggests 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. They also found that the beneficial effects of an antidepressant were diminished in mice fed a high-fat diet.

"When treating depression, in general there is no predictor of treatment resistance," Dr. Bruno Guiard, senior author of the study, said in a statement. "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," Guiard said.

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

The findings, detailed in "High fat diet-induced metabolic disorders impairs serotonergic function and anxiety-like behaviors in mice," are published in the British Journal of Pharmacology.