Schizophrenia and severe affective illness alternating over time in some patients: a hypothesis.

: There is a small portion of psychiatric patients whose symptom patterns at one point in their lives suggest a severe affective disorder and at another point a diagnosis of schizophrenia. Shifting symptom patterns such as this have heretofore been explained as misdiagnosis or dual diagnosis. An alternate hypothesis is offered--that in some patients, mental illness may be expressed in different and discrete ways at different points in their lives, depending upon intrapersonal, interpersonal, and biological processes. The rationale for the hypothesis derives from selected follow-up and family studies, treatment and drug effects, and the observed similarity of abnormal physiological measures in both diagnostic groups. Clinical implications are that one cannot always rely on family history to support a specific diagnosis on a patient's first presentation. Furthermore, if a patient subsequently presents with a significant change in symptom pattern, the therapist may wish to consider a modification of the original treatment regimen. The notion of shifting symptom patterns does not diminish the usefulness of descriptive diagnostic categories. Rather, it challenges the concept that these categories need be immutable within individuals. Compelling support for the hypothesis will necessitate prospective study of patient charts over time.