The present invention pertains to a method of diagnosing patients having chronic pain as medically unexplained symptoms, or somatization, in order to assess a probability of relief of such pain through medical treatment. The present invention is a self-reporting diagnostic test that identifies and quantifies psychological and behavioral factors that can affect treatment outcome for a patient sensitive to somatization, that might have a bearing on a decision by a physician to operate or otherwise medically treat a patient, and the problems that could occur post-operatively or after treatment. The method of the present invention diagnoses a probability of pain relief through medical treatment in a patient by administration of a test comprised of declarative statements of validity factors comprising defensiveness, predictiveness and carelessness, and clinical factors comprising somatic concern, depressed mode, passive personality, compulsive/obsessive personality, hypomania, and ego integrative defect. From the raw scores for each of the six (6) clinical factors, a scoring value of standard deviations above the normative group mean is calculated, enabling the clinician to produce a single numerical index score indicating and measuring the effect of somatization on the patient.