Faculty Bibliography

Cognitive impairment is a prominent and debilitating feature of schizophrenia. Genetic predisposition likely accounts for a large proportion of these cognitive deficits. Direct associations between candidate genes and cognitive dysfunction have been difficult to establish, however, largely due to the subtle effects of these genes on observable behavior. Neuroimaging techniques can provide a sensitive means to bridge the neurobiology of genes and behavior. Here we illustrate the use of neuroimaging-genetics paradigms to elaborate the relationship between genes and cognitive dysfunction in schizophrenia. After reviewing principles important for the selection of genes, neuroimaging techniques, and subjects, we describe how imaging-genetics investigations have helped clarify the contribution of five candidate genes (COMT, GRM3, G72, DISC1, and BDNF) to cognitive deficits in schizophrenia. The potential of this approach for improving patient care will depend on its ability to predict outcomes with greater accuracy and sensitivity than current clinical measures

OBJECTIVE: Schizophrenia patients consistently show impairments on tasks requiring inhibition such as the antisaccade task. Deficits in performance monitoring including the detection of errors and subsequent adjustments to performance may contribute to such impairments. We examined whether immediate error-related performance adjustments during the antisaccade task were intact in schizophrenia. METHOD: We compared 21 schizophrenia patients and 14 healthy control subjects on the following measures: 1) error-related, trial-by-trial adjustments in reaction time (pre-error speeding, faster errors and post-error slowing); 2) the speed-accuracy trade-off (SATO) function; and 3) the frequency and type of error self-correction. RESULTS: Although antisaccade performance in schizophrenia was characterized by increased errors and latency of correct responses, measures of immediate error-related performance adjustments were intact. CONCLUSION: Schizophrenia is characterized by intact immediate error-related performance adjustments, even in the context of impaired antisaccade performance. It is possible that deficiencies in other aspects of error processing, indexed by electrophysiological and hemodynamic markers, contribute to antisaccade and other cognitive deficits in schizophrenia

INTRODUCTION: Patients with schizophrenia show deficits in facial affect and facial identity recognition and exhibit structural and neurophysiological abnormalities in brain regions known to mediate these processes. Functional neuroimaging studies of neural responses to emotional facial expressions in schizophrenia have reported both increases and decreases in medial temporal lobe (MTL) activity in schizophrenia. Some of this variability may be related to the tasks performed and the baseline conditions used. Here we tested whether MTL responses to human faces in schizophrenia are abnormal when unconstrained by a cognitive task and measured relative to a low-level baseline (fixation) condition. METHODS: 15 patients with schizophrenia and 16 healthy control subjects underwent functional magnetic resonance imaging (fMRI) while passively viewing human faces displaying fearful, happy, and neutral emotional expressions. RESULTS: Relative to control subjects, the patients demonstrated (1) significantly greater activation of the left hippocampus while viewing all three facial expressions and (2) increased right amygdala activation during the initial presentation of fearful and neutral facial expressions. CONCLUSIONS: In schizophrenia, hippocampal and amygdala activity is elevated during the passive viewing of human faces

OBJECTIVE: We studied a sample of schizophrenia out-patients to test the hypotheses that serum homocysteine concentrations would correlate positively with measures of glucose metabolism. METHOD: Subjects underwent a nutritional assessment and fasting plasma, serum insulin and homocysteine tests. RESULTS: Males had a significantly higher homocysteine levels than females (7.69 +/- 1.42 microM vs. 6.63 +/- 1.40 microM; P = 0.02). Comparing subjects with normal fasting glucose (NFG) (glucose < 100 mg/dl) and impaired fasting glucose (IFG) (> or = 100 mg/dl) subjects with IFG (mean 8.2 +/- 1.5 microM) had significantly higher homocysteine levels than those with NFG (mean 7.2 +/- 1.4 microM, P = 0.03). IFG was also associated with greater mean values for a Homeostatic Model Assessment-Insulin Resistance (HOMA-IR) (P = 0.002) and diastolic blood pressure (P = 0.045). CONCLUSION: The group with IFG had higher fasting serum homocysteine concentrations than those with NFG which supports a connection to an important cardiovascular risk factor.

OBJECTIVE: We conducted this 6-week open-label trial to examine the effects of adjunctive aripiprazole in clozapine-treated subjects on weight, lipid and glucose metabolism, as well as positive and negative symptoms of schizophrenia. METHOD: Ten clozapine-treated subjects received aripiprazole augmentation; eight completed the 6-week trial and two ended at week 4. Eighty percent were male, the mean age was 38.7 +/- 8.9 years and the mean clozapine dose was 455 +/- 83 mg daily. RESULTS: There was a significant decrease in weight (P = 0.003), body mass index (P = 0.004), fasting total serum cholesterol (P = 0.002) and total triglycerides (P = 0.04) comparing baseline to study endpoint. There was no significant change in total Positive and Negative Syndrome Scale scores. CONCLUSION: This combination may be useful for clozapine-associated medical morbidity and must be studied in placebo-controlled double-blind randomized trials to determine efficacy and safety.

This study examined clinical predictors of client and therapist alliance ratings early in therapy, the relationship between client and therapist alliance ratings, and the psychometric properties of the Working Alliance Inventory in individuals with schizophrenia receiving manual-based treatment. Assessment of clinical symptoms and social functioning were conducted at baseline, and alliance ratings were obtained at 5 weeks. The Working Alliance Inventory had high internal consistency, but there were low correlations between client and therapist ratings. Results also indicated that social functioning and the activation and autistic preoccupation factors on the Positive and Negative Syndrome Scale were significant predictors of therapists' alliance ratings. There were no significant relationships between clinical predictors and clients' therapeutic alliance ratings. The findings indicate that client interpersonal factors are significant predictors of the therapist-rated alliance in the treatment of schizophrenia. Low correlations between clients' and therapists' ratings of the alliance should be examined in future research.

OBJECTIVE: Standardized mortality rates are elevated in schizophrenia compared to the general population. The incidence of coronary heart disease (CHD) and the relative contribution of CHD to increased mortality in schizophrenia patients are not clear, despite recent concerns about metabolic complications of certain atypical antipsychotics. METHOD: Ten-year risk for CHD was calculated for 689 subjects who participated in the Clinical Trials of Antipsychotic Treatment Effectiveness (CATIE) Schizophrenia Trial at baseline using the Framingham CHD risk function and were compared with age-, race- and gender-matched controls from the National Health and Nutrition Examination Survey (NHANES) III. RESULTS: Ten-year CHD risk was significantly elevated in male (9.4% vs. 7.0%) and female (6.3% vs. 4.2%) schizophrenia patients compared to controls (p = 0.0001). Schizophrenia patients had significantly higher rates of smoking (68% vs. 35%), diabetes (13% vs. 3%), and hypertension (27% vs. 17%) and lower HDL cholesterol levels (43.7 vs. 49.3 mg/dl) compared to controls (p < 0.001). Only total cholesterol levels did not differ between groups. Ten-year CHD risk remained significantly elevated in schizophrenia patients after controlling for body mass index (p = 0.0001). CONCLUSIONS: These results are consistent with recent evidence of increased cardiac mortality in schizophrenia patients. While the impact of cigarette smoking is clear, the relative contributions to cardiac risk of specific antipsychotic agents, diet, exercise, and quality of medical care remain to be clarified

One important risk factor for cardiovascular disease is the metabolic syndrome (MS), yet limited data exist on its prevalence in US patients with schizophrenia. METHODS: Using baseline data from the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) Schizophrenia Trial, assessment of MS prevalence was performed based on National Cholesterol Education Program (NCEP) criteria, and also using a fasting glucose threshold of 100 mg/dl (AHA). Subjects with sufficient anthropometric data, data on use of antihypertensives, hypoglycemic medications or insulin, and fasting glucose and lipid values >8 h from last meal were included in the analysis. Comparative analyses were performed using a randomly selected sample from NHANES III matched 1:1 on the basis of age, gender and race/ethnicity. RESULTS: Of 1460 CATIE baseline subjects, 689 met analysis criteria. MS prevalence was 40.9% and 42.7%, respectively using the NCEP and AHA derived criteria. In females it was 51.6% and 54.2% using the NCEP and AHA criteria, compared to 36.0% (p = .0002) and 36.6% (p = .0003), respectively for males. 73.4% of all females (including nonfasting subjects) met the waist circumference criterion compared to 36.6% of males. In a logistic regression model with age, race and ethnicity as covariates, CATIE males were 138% more likely to have MS than the NHANES matched sample, and CATIE females 251% more likely than their NHANES counterparts. Even when controlling for differences in body mass index, CATIE males were still 85% more likely to have MS than the NHANES male sample, and CATIE females 137% more likely to have MS than females in NHANES. CONCLUSIONS: The metabolic syndrome is highly prevalent in US schizophrenia patients and represents an enormous source of cardiovascular risk, especially for women. Clinical attention must be given to monitoring for this syndrome, and minimizing metabolic risks associated with antipsychotic treatment