The effects of hypertension and body mass index on diffusion tensor imaging in schizophrenia.

Recently, the negative effects of hypertension and elevated body mass index on cognitive functioning in schizophrenia have been reported (Friedman et al., 2010). Data suggests that cognitive changes in hypertensive patients from the general population may be mediated, in part, by white matter damage. Therefore, we performed diffusion tensor imaging (DTI) in the same subjects studied by Friedman et al. (2010) to investigate the effects of hypertension and elevated body mass index on the fractional anisotropy (FA) of several major white matter tracts. Significant interactions between a diagnosis of schizophrenia and hypertension on FA in several white matter regions were detected. Hypertension was associated with lower FA in the schizophrenic group and higher FA in the same tracts in the non-schizophrenic subjects. These results suggest hypertension-induced compensatory mechanisms in the brains of non-schizophrenic patients with hypertension which may be impaired in persons with schizophrenia.

Pimozide augmentation of clozapine inpatients with schizophrenia and schizoaffective disorder unresponsive to clozapine monotherapy.

Despite its superior efficacy, clozapine is helpful in only a subset of patients with schizophrenia unresponsive to other antipsychotics. This lack of complete success has prompted the frequent use of various clozapine combination strategies despite a paucity of evidence from randomized controlled trials supporting their efficacy. Pimozide, a diphenylbutylpiperidine, possesses pharmacological and clinical properties distinct from other typical antipsychotics. An open-label trial of pimozide adjunctive treatment to clozapine provided promising pilot data in support of a larger controlled trial. Therefore, we conducted a double-blind, placebo-controlled, parallel-designed 12-week trial of pimozide adjunctive treatment added to ongoing optimal clozapine treatment in 53 patients with schizophrenia and schizoaffective disorder partially or completely unresponsive to clozapine monotherapy. An average dose of 6.48 mg/day of pimozide was found to be no better than placebo in combination with clozapine at reducing Positive and Negative Syndrome Scale total, positive, negative, and general psychopathology scores. There is no suggestion from this rigorously conducted trial to suggest that pimozide is an effective augmenting agent if an optimal clozapine trial is ineffective. However, given the lack of evidence to guide clinicians and patients when clozapine does not work well, more controlled trials of innovative strategies are warranted.

The effects of hypertension and body mass index on cognition in schizophrenia.

OBJECTIVE: In recent years there has been a greater appreciation of the elevated prevalence of cardiovascular risk factors in the schizophrenia population and the liability some treatments have for their development. These vascular risk factors are in turn important risk factors in the development of dementia and more subtle cognitive impairments. However, their impact on the cognitive functions of patients with schizophrenia remains underexplored. The authors investigated whether vascular risk factors influence the cognitive impairments of schizophrenia and whether their effects on cognition in schizophrenia are different from those observed in nonpsychiatric comparison subjects. METHOD: The authors compared 100 patients with schizophrenia and 53 comparison subjects on cognitive test performance in 2×2 matrices composed of individual vascular risk factors and group (schizophrenia patients and comparison subjects). RESULTS: Hypertension exerted a significant negative effect on immediate delayed and recognition memory in both groups. Patients with schizophrenia and hypertension were adversely affected in recognition memory, whereas comparison subjects were not. A body mass index above 25 was associated with negative effects on delayed memory in both groups, although the association fell short of statistical significance. CONCLUSIONS: Given that patients with schizophrenia have a higher prevalence of vascular risk factors than the general population and are undertreated for them, treatment of these risk factors may significantly improve cognitive outcome in schizophrenia.

A pilot study of adjunctive atomoxetine treatment to second-generation antipsychotics for cognitive impairment in schizophrenia.

Relationships between altered prefrontal cortical dopamine, norepinephrine, and some of the cognitive impairments of schizophrenia support an approach for pharmacological remediation of cognitive symptoms through manipulations of prefrontal cortical dopamine and norepinephrine. Atomoxetine, a selective norepinephrine reuptake inhibitor, produces a widespread increase in brain norepinephrine and a secondary and selective increase in prefrontal dopamine. Given this, we evaluated atomoxetine's cognitive effects in a pilot placebo-controlled trial in patients with schizophrenia. Moreover, a functional magnetic resonance imaging investigation was undertaken to assess the neural mechanisms underlying the cognitive effects of atomoxetine. Twenty participants with schizophrenia were randomized to treatment with placebo or atomoxetine 80 mg daily for an 8-week parallel-designed treatment trial. Cognitive performance was assessed with the Brief Assessment of Cognition in Schizophrenia. No significant cognitive improvement was associated with atomoxetine treatment. However, atomoxetine treatment was associated with significantly greater increases in working memory-related activation of the left dorsolateral prefrontal and left posterior cingulate cortices. The negative results of this study conflict with the effectiveness of amphetamine in enhancing the cognitive abilities of schizophrenic patients and may be related to the differential pattern of cortical activation and deactivation produced by amphetamine.

The effect of citalopram adjunctive treatment added to atypical antipsychotic medications for cognitive performance in patients with schizophrenia.

Cognitive enhancement in patients with schizophrenia is a major treatment priority. Because serotonergic approaches have been suggested as a possible mechanism to enhance cognition and many patients with schizophrenia are treated with selective serotonin reuptake inhibitor antidepressants, we evaluated a serotonin reuptake inhibitor, citalopram, as adjunctive therapy to atypical antipsychotic treatment for its cognitive enhancing effects in schizophrenic patients. Nineteen schizophrenic patients were treated in a randomized, placebo-controlled, crossover-designed 24-week study. In phase 1, subjects were randomized equally to 40 mg of citalopram or placebo and were evaluated prior to initiation of pharmacotherapy and at the end of phase 1 (after 12 weeks of treatment with double-blind agent). At the beginning of phase 2, subjects were crossed over to the other treatment and subsequently assessed after 12 weeks of treatment for symptom severity and cognitive performance. There were no statistically significant differences between citalopram 40 mg/d and placebo treatment on any clinical or cognitive measures. These results indicate that citalopram adjunctive treatment to atypical antipsychotics produces no significant cognitive improvement in patients with schizophrenia. Because the subjects in this study were all treated with atypical antipsychotics, it is possible that the pharmacologic profiles of atypical antipsychotic medications at serotonin receptors may have complicated the effects of citalopram augmentation. Further research on alternative serotonergic approaches to cognitive enhancement in schizophrenia is warranted.