A patient asks for your help with fatigue, which she has been experiencing for the past several weeks. She says she is having increasing difficulty carrying out her daily responsibilities, lacks motivation and energy, and is irritable and discouraged. She reports trouble sleeping, is often late to her scheduled responsibilities, is not performing as well as previously in her job and other roles, and has had several minor injuries and mild headache and back pain.

If you are a family doctor or general practitioner, you would suspect that this woman has a major depressive disorder (MDD), although the likelihood that a depressed patient would actually present her symptoms in such a clear and obvious fashion is extraordinarily low. However, if you are a sports doctor and the patient is a competitive athlete, you may label her as being burned out, overtrained or stale, depending on your personal nomenclature for this problem. You may carry out a routine battery of laboratory tests, often including measuring a variety of immunological, hormonal, and haematological variables, consult with the athlete's coach about a modified training schedule, and suggest the athlete consider a trial of rest which may even include cessation of all training and competition. On the other hand, …