Perceived stress and life events in patients affected by schizophrenia and schizoaffective and bipolar disorder: Is there a role for self-reported basic symptoms?

Introduction: The stress-diathesis model of psychotic disorders describes, in vulnerable individuals, the role of psychosocial stress in the onset and exacerbation of psychotic symptoms. Another interesting approach to the study of vulnerability in the development of psychosis is represented by the basic symptoms concept. Objective: The present study aims at proposing an integration between these two models and investigating possible associations between psychotic symptoms, basic symptoms, perceived stress, and life events in a sample of patients affected by schizophrenia (SZ), schizoaffective (SA), and bipolar disorder with and without psychotic symptoms. Methods: 112 patients were recruited in two university hospitals. Severity of psychiatric symptoms (Positive and Negative Syndrome Scale, PANSS), basic symptoms (Frankfurt Complaint Questionnaire, FCQ), perceived stress (Stress-related Vulnerability Scale, SVS), and life events (Paykel's interview for recent life events) were assessed. Results: Patients affected by bipolar disorder (both with and without psychotic symptoms) showed a higher number of independent life events (p < 0.01) and tended to report more frequently at least 1 life event in the previous 6 months (p < 0.01) than patients affected by SZ or SA disorder. No differences emerged between the study groups in perceived stress nor in measures of basic symptoms. In the whole sample, a logistic regression analysis showed that the SVS total score (p < 0.05) and PANSS total score (p < 0.001) were associated with the presence of psychotic symptoms. Conclusions: In the study sample, life events and basic symptoms did not play a major role in influencing psychotic symptoms, compared to the subjective perception of stress and the severity of psychopathology. Taken together, these results can be informative for rehabilitation therapies aimed at enhancing resilience and coping strategies in this vulnerable group of patients.