Verbal working memory deficits predict levels of auditory hallucination in first-episode psychosis.

BACKGROUND Auditory verbal hallucinations are a characteristic symptom in schizophrenia. Recent causal models of auditory verbal hallucinations propose that cognitive mechanisms involving verbal working memory are involved in the genesis of auditory verbal hallucinations. Thus, in the present study, we investigate the hypothesis that verbal working memory is a specific factor behind auditory verbal hallucinations. METHODS In the present study, we investigated the association between verbal working memory manipulation (Backward Digit Span and Letter-Number Sequencing) and auditory verbal hallucinations in a population study (N=52) of first episode psychosis. The degree of auditory verbal hallucination as reported in the P3-subscale of the PANSS interview was included as dependent variable using sequential multiple regression, while controlling for age, psychosis symptom severity, executive cognitive functions and simple auditory working memory span. RESULTS Multiple sequential regression analyses revealed verbal working memory manipulation to be the only significant predictor of verbal hallucination severity. CONCLUSIONS Consistent with cognitive data from auditory verbal hallucinations in healthy individuals, the present results suggest a specific association between auditory verbal hallucinations, and cognitive processes involving the manipulation of phonological representations during a verbal working memory task.