Approaches used in biomedical psychiatry to evaluate depressed mood provide ambiguous information about possible underlying biological or other causes. Conventionally trained psychiatrists rely on structured interviews to obtain salient information about medical, psychiatric, family and social history that may be related to a patient’s complaint of depressed mood. The Mini-mental state exam, Beck Depression Inventory, and Hamilton Depression Inventory are structured interview tools commonly used to assess the relative severity of symptoms as well as social and psychodynamic factors associated with depressed mood. In addition to the clinical interview, laboratory screening studies are sometimes used to assess possible endocrinological, infectious, or metabolic causes of depressed mood. Bioassays that identify underlying medical causes of depressed mood include thyroid studies (FT4 and TSH), fasting blood glucose, liver enzymes, complete blood count (CBC), serum iron levels, serum electrolytes, BUN, and urinary creatinine. When an underlying medical problem, substance abuse or medication side effects contribute to mood changes, these problems are treated directly. When depressed mood does not resolve after a suspected medical cause has been treated, assessment continues until underlying psychological or medical causes are adequately addressed.
Conventional biomedical psychiatric assessment is limited by flawed standardized symptom rating instruments and poorly defined criteria for “response,” “remission,” and “recovery” when describing treatment outcomes in depression. For example a meta-analysis of 70 studies on the Hamilton depression scale suggests that this standardized instrument is conceptually flawed and does not reliably measure treatment outcomes. The response rates of most patients to conventional antidepressants are not well defined because most studies do not quantify treatment outcomes using formal criteria. Furthermore, relatively few psychiatrists are aware of, or regularly employ stringent research criteria to assess clinical outcomes when treating depressed patients.