Background: Knowledge is limited concerning somatic symptoms that cannot be accounted for by detectable somatic illness among schizophrenia patients. This study aimed to explore the prevalence, correlates, and predictors of somatization among schizophrenia patients.

Method: Initial data on all consecutively admitted adult patients with DSM-IV schizophrenia, schizoaffective disorder, major depressive disorder, or bipolar disorder were collected between August 1998 and August 2000. Standardized measures of psychopathology, somatization, emotional distress, adverse effects, insight, and stress process-related (psychosocial) variables were administered to 237 schizophrenia patients at admission and at least 12 months thereafter (N = 148). Partial correlation and multiple regression analyses were performed.

Results: The frequency of somatization, defined as the presentation of 5 or more medically unexplained somatic symptoms (Somatic Symptom Index-5), among the inpatient population (27%) did not change significantly after at least 12 months (30%; p = .61). Regression analysis showed that somatization scores were best predicted by the combination of scores for emotional distress attributed to psychopathology and side effects, expressed emotion, and insight. This combined model explains at least 40% of the variance in somatization scores. Self-esteem and social support showed negative association with somatization scores. Somatization scores were not associated with gender, age, education, age at onset, observed severity of psychopathology, subtype and duration of illness, number of admissions and treatment settings, or type and dose of antipsychotic agents.

Conclusions: Somatization is a prevalent problem among schizophrenia patients and is associated with emotional distress attributed to psychopathology, side effects of antipsychotic agents, and family members' attitudes toward schizophrenia patients. This study suggests that insight, self-esteem, and social support may protect against somatization in schizophrenia patients.

J Clin Psychiatry 2003;64(11):1370-1378