Schneiderian first-rank symptoms in schizophrenia and methamphetamine psychosis: a comparative study

• Main Author: Shelly, James Bradly
• Other Authors: Temmingh, Henk
• Format: Dissertation
• Language: English
• Published: University of Cape Town 2016
• Subjects: Psychiatry
• Online Access: http://hdl.handle.net/11427/16725

Includes bibliographical references === Objective: To determine the occurrence and associations of Schneiderian first-rank symptoms in patients diagnosed with schizophrenia and methamphetamine psychosis using structured clinical interviews for DSM-IV (SCID-I). Method: Data from SCID-I interviews collected on two samples of patients, diagnosed with schizophrenia and with methamphetamine psychosis, as part of two separate research projects, was retrieved from the respective databases and compared. The two groups were compared on the presence of any one first rank symptom, those who had two first-rank symptoms, and those who had more than two first-rank symptoms. We calculated the prevalence of different first-rank symptoms in schizophrenia and methamphetamine psychosis. We further performed a logistic regression and calculated adjusted and unadjusted odds ratios for the association between first-rank symptoms and diagnosis. Results: One hundred and two patients fulfilled inclusion criteria for the study, 33 from the methamphetamine psychosis sample, and 69 from the schizophrenia sample. Prevalence of one, two, and more than two first-rank symptoms in the methamphetamine psychosis and schizophrenia groups was calculated as 69.6% and 69.7%, 21.2% and 20.3 %, and 27.3% and 27.5% respectively. After adjusting for covariates, thought broadcasting occurred significantly more often in patients with schizophrenia compared to those with methamphetamine psychosis (Odds ratio=3.61; 95% CI: 1.26-10.33; p<0.05). In turn, the odds of having auditory hallucinations in the form of voices conversing was significantly lower in patients with schizophrenia compared to those with methamphetamine psychosis (Odds ratio=0.27; 95% CI: 0.1-0.75; p<0.05). We found no significant association between any other first-rank symptoms as measured by the SCID-I and a diagnosis of schizophrenia or methamphetamine psychosis. Conclusion: The symptom of thought broadcasting was significantly more likely to occur in patients diagnosed with schizophrenia than in patients diagnosed with methamphetamine psychosis. Auditory hallucinations of voices heard conversing was significantly less likely to occur in patients with schizophrenia than in those with methamphetamine psychosis. Overall, there was a significant overlap of first-rank symptoms and a diagnosis of either schizophrenia or methamphetamine psychosis, but this study did not show that patients with a diagnosis of schizophrenia are more likely to have first-rank symptoms when compared to those with methamphetamine psychosis.