Biologic tests in depression

Although abnormalities in many biologic measures are far more frequent in depressed patients than in healthy controls, their presence in other neuropsychiatnc and general medical disorders severely limits their clinical usefulness. Despite these drawbacks, some of the proposed biologic “tests” for depression may be useful in monitoring recovery, predicting relapse, or delineating special patient subpopulations (eg, impulsive and suicidal patients). The authors examine the current status of work with these tests. Considerable further research is needed before their possible utility in clinical practicecan be accurately determined.