Alpha lipoic acid: a novel treatment for depression

Insulin resistance has been associated with people diagnosed with depressio n. Conversely, it has also been documented that diabetics have an increased risk of depression. Evidence suggests that insulin activity prays a role i n serotonergic activity by increasing the influx of tryptophan into the bra in. This increased influx of tryptophan has been shown to result in an incr ease in serotonin synthesis. In accordance with the serotonin theory of dep ression,it may be possible to treat depression by increasing insulin activi ty. The antioxidant alpha lipoic acid has been shown to increase insulin se nsitivity and is used to treat people with diabetes. Therefore, the nutrien t alpha lipoic acid should be clinically tested as an adjunct treatment for depression. (C) 2000 Harcourt Publishers Ltd.