Characterization of pain and somatization and its relationship with psychopathology in early onset psychosis☆

Background: Early onset psychosis (EOP) frequently presents with a severe clinical phenotype and poor long-term prognosis. Clinical experience suggests that individuals with EOP have abnormal pain and somatosensory processing, yet relative to adult-onset psychosis, pain and somatic sensory processing in EOP have rarely been studied. Methods: The history of two characteristic patients is described to illustrate clinical presentations of pain in EOP patients. Furthermore, 31 patients with EOP were studied with self-reported questionnaires informing on pain severity, pain catastrophizing, central sensitization, and somatization. Structured clinical interviews were administered to confirm Diagnostic and Statistical Manual of Mental Disorders-5 EOP diagnosis and the patient's dimensions of psychopathology were measured by the Brief Psychiatric Rating Scale (BPRS). Results: Out of 31 EOP patients, 22 reported distressing pain, where higher pain severity corresponded with greater BPRS total and affectivity and resistance subscale scores. The degree of psychopathology was associated (N = 31; p < 0.05, FDR-corrected) with the magnitude of pain catastrophizing, central sensitization, and somatization. Multivariate analysis revealed relationships (N = 31; p < 0.05, FDR-corrected) between BPRS subscale (negative symptoms and activation) scores with somatization severity. The observed associations occurred independent of antipsychotic medication usage as quantified by chlorpromazine equivalent doses. Conclusions: Pain and somatosensory symptoms could be a frequent cause of distress in patients with EOP and their severity associated with the degree of psychopathology. Future studies should determine if treating pain and somatic symptoms in EOP patients can lead to better control of psychosis as well as improve quality of life.