Faculty Bibliography

While it is recognized that depression frequently can occur together with fundamental symptoms of schizophrenia, estimates of the prevalence of schizophrenia-related depression have been very variable. This variability may be due in part to the difficulty in clearly separating depressive symptoms from negative symptoms. A more valid method of assessing depression might combine evaluations from multiple vantage points. This study, which involved 26 hospitalized schizophrenic patients, tested the proposition that complete assessment of depression requires three separate sources of input: self-rating (subjective mood state), clinician rating (affective state), and observer rating (behavioral manifestations). In the present study, patients were evaluated on self-rating instruments for mood states, clinician-rated scales including the Hamilton Rating Scale for Depression, and observer-rated scales. These vantage points, though overlapping in some respects, were found to provide independent information on the experience of depression in schizophrenia. Clinician-rated and observer-rated assessments tended to correlate significantly, while self-rated subjective reports were discordant, thus complementing the assessments from the other two vantage points

This study investigates the occurrence of depression and related psychopathological features in chronic schizophrenics and attempts to examine whether depressive symptoms are independent of negative symptoms. We found that 54% of our sample of 240 chronic schizophrenics exhibited moderate to severe depression. Independent t tests showed that those high in depression tended to exhibit significantly more positive symptoms as defined by the Positive and Negative Syndrome Scale (PANSS). Those with high depression do not exhibit significantly worse negative symptoms compared with low depression, clearly differentiating depression from negative symptoms. Results and the relationship to a previous factor-analytic study of schizophrenic symptoms are discussed.

Current models of schizophrenia postulate that different symptom complexes, including the positive and negative, may relate to fundamental underlying neurobiological distinctions. However, the premise of an underlying stability to the psychopathological profile has not been systematically investigated, particularly in response to pharmacological intervention. The present work aimed to study this issue in 14 chronic schizophrenic inpatients by comparing their symptom clusters before and after a 20-week course of clozapine treatment. The results indicated significant improvement on all eight symptom dimensions, as well as in severity of general psychopathology. Despite the clinical gains, most dimensions remained highly stable, with correlations between prestudy and clozapine week 20 ranging up to .91 (P less than .0001) for the positive-negative composite score. These findings of stability over time, even in response to potent treatment, support the validity and importance of schizophrenic psychopathology dimensions, which appeared to possess fundamental traitlike characteristics.

Enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescent-antibody assay (IFA), and Western immunoblot were used to test serum samples from 128 dogs for the presence of antibody to Borrelia burgdorferi. Sera included 72 samples from dogs suspected of having Lyme disease, 32 samples from dogs residing in areas in which Lyme disease was not considered endemic, and 24 samples from dogs with clinical and serologic evidence of immune-mediated disease (n = 10), Rocky Mountain spotted fever (n = 5), or leptospirosis (n = 9). Results of Western immunoblotting were used as the standard against which performances of ELISA and IFA were measured. ELISA was significantly more sensitive than IFA (84.8 versus 66.7%), although both tests were equally specific (93.5%). Eight samples that were positive by Western immunoblot were simultaneously negative by ELISA and IFA. Of these eight, four were from dogs suspected of having immune-mediated disease, two were from dogs suspected of having leptospirosis, and two were from dogs suspected of having Lyme disease. These results may indicate that sera from dogs with immune-mediated disease, and to a lesser extent sera from those with leptospirosis, cross-react with B. burgdorferi antigens. Alternatively, Western immunoblot results may not truly reflect Lyme disease status, particularly in the case of dogs with immune-mediated diseases. At present, however, the use of Western immunoblotting as a diagnostic standard for dogs offers the best alternative to a clinical definition of disease.