Emotional discomfort and impairments in verbal memory in schizophrenia

Research has demonstrated that impairments in verbal memory in schizophrenia are linked with psychosocial deficits. Less is known, however, about their relationship to clinical features of illness. This study explores the hypothesis that impairments in verbal memory, particularly forms of memory requiring deeper levels of encoding, are uniquely linked to symptoms of dysphoria or emotional discomfort. Accordingly, we examined the association between concurrent measures of symptoms and verbal memory for 84 subjects with schizophrenia. Measures of positive, negative, cognitive, excitement and emotional discomfort symptoms were derived from factor scores of the Positive and Negative Syndrome Scale. Verbal memory was assessed using two tests requiring relatively superficial levels of encoding: The Hopkins Verbal Memory Test and the Digit Span subtest; and one test requiring deeper levels of encoding: the Logical Memory subtests I and II. As predicted, multiple regressions controlling for age, education and attention revealed that poorer performance on Logical Memory was strongly associated with greater levels of emotional discomfort (R(2)=0.22 and 0.25, respectively) while performance on the Hopkins test was related to cognitive symptoms scores (R(2)=0.08 and 0.09, respectively). Implications for the conceptualization of verbal memory deficits in schizophrenia are discussed.