Psychiatry Research EG

Background Negative symptoms of schizophrenia, account vastly for its functional disability and often persist despite pharmacological treatment. Aim The aim of the study was to detect cases of resistant negative schizophrenia in institutionalized patients, compare between groups of resistant and nonresistant cases, formulate comprehensive criteria for resistant schizophrenia with different positive and negative symptoms, and find predictors of resistance. Patients and methods According to DSMIV-SCID, 95 chronic schizophrenia patients were examined by BPRS, PANSS, CGIS, and MMSE. Clinical data, treatment history, and medical state were collected. Operational definition for negative resistant schizophrenia was acquired from PANSS and CGIS scores, and Modified Kane’s criteria for resistant schizophrenia. Cases were divided into four groups: resistant schizophrenia with predominant negative symptoms (n= 26), resistant schizophrenia (modified Kane’s criteria) (n= 25), overlapped resistant cases (n= 11), and nonresistant cases (n= 33). Results Resistant schizophrenia patients and cases with predominant negative symptoms scored significantly higher (P= 37.19± 7.3) on mean negative scores (P= 0.000), as well as all resistant groups (n= 62) compared to nonresistant cases (n= 33) (P= 0.000, mean 34.08± 8.9). Resistant negative schizophrenia group scored significantly lower on MMSE (P= 0.05). The most powerful predictors for resistant negative schizophrenia were cognitive deficits presented by low score in MMSE, high score on disorientation and lack of attention items. Conclusion Presence of subgroup of patients with predominant negative symptoms, and not included in the definition of resistant schizophrenia, indicates that the available diagnostic criteria need to be reviewed. Cognitive dysfunction linked to negative schizophrenia suggests a bidirectional effect and possibility of a biological predisposition behind resistance other than social or environmental factors. Keywords: cognitive dysfunction in schizophrenia, negative schizophrenia, resistant schizophrenia