As much as half of all cases of depression have a physical, rather than emotional or psychological, cause (Am J Psychiatry, 1981; 138: 629-35). Two conditions that are often missed by doctors are common:
* Hypothyroidism. Up to 25 per cent of depressed individuals, most of them women, suffer from subclinical hypothyroidism, a subtle dysfunction of the thyroid gland (Curr Psychiatry Rep, 2003; 5: 384-90; Thyroid, 1998; 8: 951-6). The condition can be missed by the standard screening tests, so consider a thyrotrophin-releasing hormone (TRH) stimulation test, or one that looks for antithyroid antibodies. Once diagnosed, the use of thyroid hormones can alleviate depression.
* Reactive hypoglycaemia. Compulsive snacking or bingeing on sweet or starchy food may be part of a cycle of reactive hypoglycaemia (Nutrition, 1997; 13: 503-14). Once you reduce or remove carbohydrates, your moods should even out.