Usefulness of a standard battery of laboratory tests in investigating chronic fatigue in adults.

Twenty-two adults with chronic fatigue were studied to determine the clinical usefulness of commonly applied laboratory tests. Subjects with the chief complaint of fatigue persisting for more than one year were followed for an average of seven months at a university family health centre. During this time a group of commonly recommended tests were carried out and the patients had repeated physical examinations. Physical diseases and laboratory abnormalities were few, and patients with abnormal values and active problems were followed until their fatigue resolved or their abnormalities reverted to normal following therapy. The study demonstrated that the presence of an abnormal laboratory result in a fatigued individual does not necessarily indicate the cause of fatigue. A psychiatric history was also performed and patients were tested with the symptom check list 90-R (SCL-90-R), a 90-item psychological symptom check list. Seven patients were receiving psychotherapy when they enrolled in the study. Two additional subjects entered therapy after the start of the study. Results on the symptom check list for the study group were largely abnormal, with a majority scoring in the highest quartile for depression, paranoid ideation and psychoticism. It is concluded that the investigation of patients with fatigue which has lasted for longer than one year should focus on psychological causes. In this group of patients laboratory abnormalities are not useful in guiding evaluation or treatment for their fatigue.