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People with schizophrenia demonstrate impairments in selective attention, working memory, and executive function. Given the overlap in these constructs, it is unclear if these represent distinct impairments or different manifestations of one higher-order impairment. To examine this question, we administered tasks from the basic cognitive neuroscience literature to measure visual selective attention, working memory capacity, and executive function in 126 people with schizophrenia and 122 healthy volunteers. Patients demonstrated deficits on all tasks with the exception of selective attention guided by strong bottom-up inputs. Although the measures of top-down control of selective attention, working memory, and executive function were all intercorrelated, several sources of evidence indicate that working memory and executive function are separate sources of variance. Specifically, both working memory and executive function independently contributed to the discrimination of group status and independently accounted for variance in overall general cognitive ability as assessed by the MATRICS battery. These two cognitive functions appear to be separable features of the cognitive impairments observed in schizophrenia.

BACKGROUND: Morbidity and premature mortality is high in schizophrenia. Poor diets, low rates of physical activity, substance use, and lack of preventative care predispose patients to poor physical health and comorbid medical diseases. Women with schizophrenia have distinct preventative and physical health needs which poses and even greater burden on disease risk. We evaluated laboratory measures and health indices in women with schizophrenia having antipsychotic-induced hyperprolactinemia. METHODS: This study includes data from a one-time fasting laboratory screening visit in women treated with prolactin elevating antipsychotics (N=43). Laboratories were drawn in the follicular phase of the menstrual cycle if possible. Women were between the ages of 18–50 years and had a known high prolactin level (

Background: Hyperprolactinemia, a side effect of antipsychotic treatment, causes amenorrhea, oligomenorrhea, galactorrhea, gynecomastia, and sexual dysfunction. These side effects increase risk of antipsychotic nonadherence and pose significant problems in the long-term management, particularly in women with severe mental illness.

Objective: We examined perceived consequences/benefits of cigarette smoking and motivation for quitting in nontreatment-seekingsmokerswhohadschizophreniaorschizoaffective disorder (N 5 100) or had no Axis I psychiatric disorder (normals, N 5 100). Methods: Participants completed questionnaires and provided a breath carbon monoxide (CO) sample 10–15 minutes after smoking 1 preferredbrand cigarette. Primary assessments included the Smoking Consequences Questionnaire-Adult, the Reasons for Quitting Scale, and the Stages of Change. Results: There were no differences between the schizophrenia and control group in mean age of smoking onset (16.2 5.4 vs 15.6 5.5 y, P 5 .44), number of cigarettes daily (17.9 11.6 vs 17.0 7.9, P 50.51),orinbreathCO(28.0 14.5vs22.9 8.0ppm,P 5 .61).Comparedwithnormals,peoplewithschizophreniareportgreater stimulation/state enhancement (P

The levels of kynurenic acid (KYNA), an astrocyte-derived metabolite of the branched kynurenine pathway (KP) of tryptophan degradation and antagonist of α7 nicotinic acetylcholine and N-methyl-D-aspartate receptors, are elevated in the prefrontal cortex (PFC) of individuals with schizophrenia (SZ). Because endogenous KYNA modulates extracellular glutamate and acetylcholine levels in the PFC, these increases may be pathophysiologically significant. Using brain tissue from SZ patients and matched controls, we now measured the activity of several KP enzymes (kynurenine 3-monooxygenase [KMO], kynureninase, 3-hydroxyanthranilic acid dioxygenase [3-HAO], quinolinic acid phosphoribosyltransferase [QPRT], and kynurenine aminotransferase II [KAT II]) in the PFC, ie, Brodmann areas (BA) 9 and 10. Compared with controls, the activities of KMO (in BA 9 and 10) and 3-HAO (in BA 9) were significantly reduced in SZ, though there were no significant differences between patients and controls in kynureninase, QPRT, and KAT II. In the same samples, we also confirmed the increase in the tissue levels of KYNA in SZ. As examined in rats treated chronically with the antipsychotic drug risperidone, the observed biochemical changes were not secondary to medication. A persistent reduction in KMO activity may have a particular bearing on pathology because it may signify a shift of KP metabolism toward enhanced KYNA synthesis. The present results further support the hypothesis that the normalization of cortical KP metabolism may constitute an effective new treatment strategy in SZ.

Use of placebo-controlled trials in medical and psychiatric research has been controversial, although a consensus is emerging about conditions under which placebo-controlled trials are ethical. In schizophrenia research, the paradigm of slow onset of antipsychotic effects has led to a model in which placebo-controlled trials of 6-8 weeks duration have been used to demonstrate efficacy. Recent evidence that the largest symptom reductions are typically seen in the first weeks of treatment suggests that shorter placebo-controlled studies to demonstrate antipsychotic efficacy are possible. In a pilot study of the feasibility of shortening placebo-controlled studies, we reanalyzed data from placebo-controlled registry trials of olanzapine and risperidone and found that trials as short as 4 weeks could have similar power to longer term 6-8 week studies, given the estimated time course of treatment effects. Although fuller evaluation is required, the results suggest future antipsychotic trials could be shortened from 6-8 weeks to 3-4 weeks with a relatively low increase in sample size requirements. Shortening placebo-controlled trials would reduce patient burden and ethical objections to prolonged administration of placebo and reduce potential bias due to high dropout rates in longer clinical trials.

Research suggests that first-degree relatives and individuals with schizophrenia spectrum personality disorders (SSPD) may represent nonpenetrant carriers of the genetic diathesis for schizophrenia. This study examined visuospatial working memory (SWM) as a cognitive endophenotype of schizophrenia by expanding the concept of risk for pathophysiological dysfunction beyond overt psychosis. Risk was thus defined by familial status and the presence or absence of SSPD. SWM was assessed in the following groups, in order of decreasing likelihood of genetic vulnerability: 23 patients with schizophrenia, 17 SSPD relatives of patients with schizophrenia, 23 non-SSPD relatives of patients with schizophrenia, 14 SSPD community members with no family history of psychosis, and 36 non-SSPD community members. SWM performance during a computer task was quantified by A-Prime. Relative risk ratios for SWM deficits were compared among the groups. Compared with community non-SSPD volunteers, relative risk (RR) of SWM deficits was significantly elevated in patients with schizophrenia (RR = 3.76, p = .002) and SSPD family members (RR = 2.97, p = .027), but not in the family non-SSPD (RR = 1.88, p = .241) or community SSPD (RR = 1.03, p = .971) groups. The pattern of SWM performance deficits reflected the proposed model of latent genetic liability, upholding SWM as a viable cognitive endophenotype. The results underscore the importance of including both familial liability and the schizophrenia spectrum when considering risk for schizophrenia and schizophrenia-related traits. This is particularly relevant for research efforts to identify pathophysiological components of the disease.

There is considerable evidence that schizophrenia spectrum personality (SSP) disorders mark genetic risk for schizophrenia. Use of the spectrum phenotype in genetic and neurophysiological studies may prove informative. However, the degree to which the current diagnostic criteria correspond with genetic risk is unclear. This can be assessed by observing how measures of liability among SSP subjects change as a function of diagnostic criteria. In this study the generalized estimating equation method was used to assess changes in eye-tracking performance among SSP and non-SSP family and community groups employing various diagnostic criteria. Eye-tracking deficits among SSP relatives remained statistically higher compared with the other groups across progressively more liberal SSP criteria. The results suggest that fewer traits than are used in clinical diagnoses can effectively identify the spectrum phenotype among relatives of schizophrenia patients. Thus, reduced criteria may be used in research to increase "high risk" sample size and power to detect neurophysiological and genetic differences. Our results provide suggestive evidence that the use of clinical criteria in research may, in fact, underidentify at-risk individuals--potentially distorting genetic and neurophysiological findings.