Is schizophrenia a syndrome of accelerated aging?

Dedifferentiation and substitute strategy: deconstructing the processing-speed impairment in schizophrenia

BACKGROUND

Recent research has identified impairment in processing speed, measured by the digit-symbol substitution task, as central to the cognitive deficit in schizophrenia. However, the underlying cognitive correlates of this impairment remain unknown.

METHODS

A sample of cases (N=125) meeting DSM-IV criteria for schizophrenia and a sample of community controls (N=272) from the same geographical area completed a set of putative measures of processing-speed ability to which we implemented confirmatory factor and structural regression modelling in order to elucidate the latent structure of processing speed. Next, we tested the degree to which the structural and relational portions of the model were equal across groups.

RESULTS

Processing-speed ability was best defined, in both controls and cases (χ(2)=38.59(26), p=0.053), as a multidimensional cognitive ability consisting of three latent factors comprising: psychomotor speed, sequencing and shifting, and verbal fluency. However, cases exhibited dedifferentiation (i.e., markedly stronger inter-correlations between factors; χ(2)=59.94(29), p<.01) and a reliance on an alternative ensemble of cognitive operations to controls when completing the digit-symbol substitution task.

CONCLUSION

Dedifferentiation of processing-speed ability in schizophrenia and subsequent overreliance on alternative (and possibly less than optimal) cognitive operations underlies the marked deficit observed on the digit-symbol substitution task.

Assessing clinical and functional outcomes in a gene-environment interaction study in first episode of psychosis (PEPs)

The PEPs study is a multicenter, naturalistic, prospective, longitudinal study designed to evaluate clinical, neuropsychological, neuroimaging, biochemical, environmental and pharmacogenetic variables in a sample of nearly 350 first episode of psychosis patients and 250 healthy controls. The PEPs project was conducted in Spain from January 2009 to December 2011. This article describes the rationale for the measurement approach adopted, providing an overview of the selected clinical and functional measures. The main objectives are: a) the thorough clinical and neurocognitive characterization of a sample of first episodes of psychosis, and b) the study of the interactions between the genetic and environmental variables selected to predict clinical and brain structural outcomes, and to determine the relationship of genetic polymorphisms involved in the pharmacokinetics and pharmacodynamics, and the responses and adverse effects of treatment.

Brain maturation: predicting individual BrainAGE in children and adolescents using structural MRI

BACKGROUND

Neural development during human childhood and adolescence involves highly coordinated and sequenced events, characterized by both progressive and regressive processes. Despite a multitude of results demonstrating the age-dependent development of gray matter, white matter, and total brain volume, a reference curve allowing prediction of structural brain maturation is still lacking but would be clinically valuable. For the first time, the present study provides a validated reference curve for structural brain maturation during childhood and adolescence, based on structural MRI data.

METHODS AND FINDINGS

By employing kernel regression methods, a novel but well-validated BrainAGE framework uses the complex multidimensional maturation pattern across the whole brain to estimate an individual's brain age. The BrainAGE framework was applied to a large human sample (n=394) of healthy children and adolescents, whose image data had been acquired during the NIH MRI study of normal brain development. Using this approach, we were able to predict individual brain maturation with a clinically meaningful accuracy: the correlation between predicted brain age and chronological age resulted in r=0.93. The mean absolute error was only 1.1 years. Moreover, the predicted brain age reliably differentiated between all age groups (i.e., preschool childhood, late childhood, early adolescence, middle adolescence, late adolescence). Applying the framework to preterm-born adolescents resulted in a significantly lower estimated brain age than chronological age in subjects who were born before the end of the 27th week of gestation, demonstrating the successful clinical application and future potential of this method.

CONCLUSIONS

Consequently, in the future this novel BrainAGE approach may prove clinically valuable in detecting both normal and abnormal brain maturation, providing important prognostic information.

After six months of anti-psychotic treatment: Is the improvement in mental health at the expense of physical health?

INTRODUCTION

The morbidity and mortality due to cardiovascular causes in patients with schizophrenia is higher than in the general population, a fact that has been observed more since second generation anti-psychotics came into general use.

OBJECTIVES

To determine the incidence of metabolic syndrome in patients with a previously untreated first psychotic episode, as well as the prospective changes in the parameters that define the criteria of metabolic syndrome.

METHOD

An observational study with a prospective cohort design including patients who were admitted to the Acute Unit of Donostia Hospital.

RESULTS

A total of 21 patients were included in the study, of which 19 completed it. Just over one-quarter (26.3%) of the patients developed a metabolic syndrome at six months. Statistically significant differences were observed in the following parameters: 1) abdominal perimeter measurement with an increase of 14.6 cm at six months (P=.001); 2) triglyceride levels with a mean increase over the initial measurement of 48.99 mg/dl (P=.039); and 3) fasting blood glucose levels with a mean increase of 10.72 mg/dl (P=.001).

CONCLUSIONS

Significant changes were observed in metabolic parameters in a short period with the subsequent risk of associated cardiovascular events in a group of young patients. Actions are required directed at ensuring appropriate monitoring of these patients in order to measures to minimise the risks.

Impact of the Reelin signaling cascade (ligands-receptors-adaptor complex) on cognition in schizophrenia

Our previous neurocognitive studies of schizophrenia outlined two clusters of affected subjects--cognitively spared (CS) and cognitive deficit (CD), the latter's characteristics pointing to developmental origins and impaired synaptic plasticity. Here we investigate the contribution of polymorphisms in major regulators of these processes to susceptibility to schizophrenia and to CD in patients. We examine variation in genes encoding proteins at the gateway of Reelin signaling: ligands RELN and APOE, their common receptors APOER2 and VLDLR, and adaptor DAB1. Association analysis with disease outcome and cognitive performance in the Western Australian Family Study of Schizophrenia (WAFSS) was followed by replication analysis in the Australian Schizophrenia Research Bank (ASRB) and in the Health in Men Study (HIMS) of normal aging males. In the WAFSS sample, we observed significant association of APOE, APOER2, VLDLR, and DAB1 SNPs with disease outcome in the case-control and CD-control datasets, and with pre-morbid intelligence and verbal memory in cases. HIMS replication analysis supported rs439401 (APOE regulatory region), and rs2297660 and rs3737983 (APOER2), with an effect on memory performance in normal aging subjects consistent with the findings in schizophrenia cases. APOER2 gene expression analysis revealed lower transcript levels in lymphoblastoid cells from cognitively impaired schizophrenia patients of the alternatively spliced exon 19, mediating Reelin signaling and synaptic plasticity in the adult brain. ASRB replication analysis produced marginally significant results, possibly reflecting a recruitment strategy biased toward CS patients. The data suggest a contribution of neurodevelopmental/synaptic plasticity genes to cognitive impairment in schizophrenia.

A critical review of major mortality risk factors for all-cause mortality in first-episode schizophrenia: clinical and research implications

A bibliographical search was performed to identify and evaluate the impact in first-episode schizophrenia of the major mortality risk factors as described by the World Health Organisation (2009). We found that at first diagnosis rates of diabetes were only slightly increased, although lipid abnormalities, mild hypertension and being overweight were commonly reported. Levels of drug and alcohol abuse were high, as were pre-diagnosis rates of smoking, physical inactivity and poor cardiorespiratory fitness. During the first year of antipsychotic treatment, there were significant increases in the rates of hyperglycaemia/diabetes, obesity, lipid abnormalities and hypertension, but no changes in fitness levels, smoking or drug and alcohol abuse. In chronic schizophrenia, excess cancer and cardiac deaths seem linked in part to availability and quality of care. Innate risk factors such as abnormal reelin and raised prolactin may also be important. New evidence, such as an inverse relationship between body mass index and suicide in the general population, suggests accepted wisdom may not apply to patients at high risk of ending their own lives. With current knowledge emphasis needs to be placed by early intervention services on physical fitness, smoking and other substance misuse, diabetes and hypertension, as well as focusing on weight reduction only in the obese.

Restoration of synaptic plasticity and learning in young and aged NCAM-deficient mice by enhancing neurotransmission mediated by GluN2A-containing NMDA receptors

Neural cell adhesion molecule (NCAM) is the predominant carrier of the unusual glycan polysialic acid (PSA). Deficits in PSA and/or NCAM expression cause impairments in hippocampal long-term potentiation and depression (LTP and LTD) and are associated with schizophrenia and aging. In this study, we show that impaired LTP in adult NCAM-deficient (NCAM(-/-)) mice is restored by increasing the activity of the NMDA subtype of glutamate receptor (GluN) through either reducing the extracellular Mg2+ concentration or applying d-cycloserine (DCS), a partial agonist of the GluN glycine binding site. Pharmacological inhibition of the GluN2A subtype reduced LTP to the same level in NCAM(-/-) and wild-type (NCAM(+/+)) littermate mice and abolished the rescue by DCS in NCAM(-/-) mice, suggesting that the effects of DCS are mainly mediated by GluN2A. The insufficient contribution of GluN to LTD in NCAM(-/-) mice was also compensated for by DCS. Furthermore, impaired contextual and cued fear conditioning levels were restored in NCAM(-/-) mice by administration of DCS before conditioning. In 12-month-old NCAM(-/-), but not NCAM(+/+) mice, there was a decline in LTP compared with 3-month-old mice that could be rescued by DCS. In 24-month-old mice of both genotypes, there was a reduction in LTP that could be fully restored by DCS in NCAM(+/+) mice but only partially restored in NCAM(-/-) mice. Thus, several deficiencies of NCAM(-/-) mice can be ameliorated by enhancing GluN2A-mediated neurotransmission with DCS.

The efficacy of supported employment for middle-aged and older people with schizophrenia

OBJECTIVE

Supported employment is the evidence-based treatment of choice for assisting individuals with severe mental illness to achieve competitive employment, but few supported employment programs specifically target older clients with psychiatric illness. The purpose of this study was to evaluate the efficacy of supported employment for middle-aged or older people with schizophrenia.

METHOD

Participants included 58 outpatients with schizophrenia or schizoaffective disorder aged 45 or older who were recruited from a community mental health clinic. Participants were randomly assigned to receive Individual Placement and Support (IPS; the manualized version of supported employment) or conventional vocational rehabilitation (CVR) for one year, and completed assessments at baseline, six months, and twelve months.

RESULTS

IPS was superior to CVR on nearly all work outcome measures, including attainment of competitive employment, weeks worked, and wages earned. Fifty-seven percent of IPS participants worked competitively, compared with 29% of CVR participants; 70% of IPS participants obtained any paid work, compared with 36% of CVR participants. Within the IPS group, better baseline functional capacity (as measured by the UCSD Performance Based Skills Assessment) and more recent employment were modestly associated with better work outcomes.

CONCLUSIONS

Middle-aged and older adults with schizophrenia are good candidates for supported employment services.

Schizophrenia as segmental progeria

Schizophrenia is associated with a variety of physical manifestations (i.e. metabolic, neurological) and despite psychotropic medication being blamed for some of these (in particular obesity and diabetes), there is evidence that schizophrenia itself confers an increased risk of physical disease and early death. The observation that schizophrenia and progeroid syndromes share common clinical features and molecular profiles gives rise to the hypothesis that schizophrenia could be conceptualized as a whole body disorder, namely a segmental progeria. Mammalian cells employ the mechanisms of cellular senescence and apoptosis (programmed cell death) as a means to control inevitable DNA damage and cancer. Exacerbation of those processes is associated with accelerated ageing and schizophrenia and this warrants further investigation into possible underlying biological mechanisms, such as epigenetic control of the genome.

Testosterone in newly diagnosed, antipsychotic-naive men with nonaffective psychosis: a test of the accelerated aging hypothesis

OBJECTIVE

Schizophrenia has been associated with age-related abnormalities, including abnormal glucose tolerance, increased pulse pressure, increased inflammation, abnormal stem cell signaling, and shorter telomere length. These metabolic abnormalities and other findings suggest that schizophrenia and related disorders might be associated with accelerated aging. Testosterone activity has a progressive decline with increasing age.

METHODS

We tested the hypothesis that circulating biologically active testosterone is lower in newly diagnosed, antipsychotic-naive male patients with nonaffective psychosis than in matched control subjects.

RESULTS

Patients (n = 33) were matched to control subjects (n = 33) for age, sex, body mass index, socioeconomic status of the family of origin, and smoking. The free androgen index, a measure of biologically active testosterone, was significantly lower in the psychosis group (mean [standard deviation] = 57.7% [26.1]) than in control subjects (71.6% [27.0], p = .04), with an effect size of 0.53. Multivariate analysis also supported the findings. In the psychosis group, free androgen index had a significant negative correlation with the conceptual disorganization item (r = -0.35, p = .049) but not with reality distortion (r = -0.21, p = .24), negative symptoms (r = 0.004, p = .98), or depression (r = -0.014, p = .94).

CONCLUSIONS

Lower testosterone level is consistent with accelerated aging in nonaffective psychosis, but further testing of this hypothesis is needed.

Antioxidants, redox signaling, and pathophysiology in schizophrenia: an integrative view

Schizophrenia (SZ) is a brain disorder that has been intensively studied for over a century; yet, its etiology and multifactorial pathophysiology remain a puzzle. However, significant advances have been made in identifying numerous abnormalities in key biochemical systems. One among these is the antioxidant defense system (AODS) and redox signaling. This review summarizes the findings to date in human studies. The evidence can be broadly clustered into three major themes: perturbations in AODS, relationships between AODS alterations and other systems (i.e., membrane structure, immune function, and neurotransmission), and clinical implications. These domains of AODS have been examined in samples from both the central nervous system and peripheral tissues. Findings in patients with SZ include decreased nonenzymatic antioxidants, increased lipid peroxides and nitric oxides, and homeostatic imbalance of purine catabolism. Reductions of plasma antioxidant capacity are seen in patients with chronic illness as well as early in the course of SZ. Notably, these data indicate that many AODS alterations are independent of treatment effects. Moreover, there is burgeoning evidence indicating a link among oxidative stress, membrane defects, immune dysfunction, and multineurotransmitter pathologies in SZ. Finally, the body of evidence reviewed herein provides a theoretical rationale for the development of novel treatment approaches.

Divergent trajectories of physical, cognitive, and psychosocial aging in schizophrenia

Aging is not a uniform process. In the general population, there is a paradox of aging: age-associated decline in physical and some cognitive functions stands in contrast to an enhancement of subjective quality of life and psychosocial functioning. This paradox is even more striking in people with schizophrenia. Compared with the overall population, individuals with schizophrenia have accelerated physical aging (with increased and premature medical comorbidity and mortality) but a normal rate of cognitive aging, although with mild cognitive impairment starting from premorbid period and persisting throughout life. Remarkably, psychosocial function improves with age, with diminished psychotic symptoms, reduced psychiatric relapses requiring hospitalization and better self-management. Many older adults with schizophrenia successfully adapt to the illness, with increased use of positive coping techniques, enhanced self-esteem and increased social support. Although complete remission is uncommon, most individuals with schizophrenia experience significant improvement in their quality of well-being. Cohort effect and survivor bias may provide a partial explanation for this phenomenon. However, the improvement also may reflect some brain changes that are beneficial for the course of schizophrenia along with neuroplasticity of aging. The proposed hypothesis has several implications. As significant medical morbidity in schizophrenia takes years to develop, studies of changes in sensitive biomarkers of aging during the course of illness may point to new treatments aimed at normalizing the rate of biological aging in schizophrenia. At the same time, effective psychotherapeutic interventions can affect brain structure and function and produce lasting positive behavioral changes in aging adults with schizophrenia.

A longitudinal study on the impact of antipsychotic treatment on serum leptin in schizophrenia

OBJECTIVE

The study objective was to explore the biological basis for link between antipsychotic-induced weight gain and therapeutic response in schizophrenia by examining longitudinal changes in serum leptin level after antipsychotic treatment.

METHODS

We examined serum leptin in schizophrenia patients at antipsychotic-naive baseline status as well as after 3 months of antipsychotic treatment. For baseline analyses, the patients were compared with healthy controls matched for anthropometric measures and physical activity.

RESULTS

At baseline, schizophrenia patients had significantly lower levels of leptin in comparison with controls. After treatment, body mass index and levels of leptin increased significantly in patients. The magnitude of increase in leptin had a significant positive correlation with magnitude of increase in body mass index; the magnitude of reduction in SANS total score showed significant positive correlation with the magnitude of increase in leptin level.

CONCLUSION

The study findings suggest a potential role for leptin to mediate the link between antipsychotic-induced weight gain and beneficial therapeutic response in schizophrenia.

Different characteristics of cognitive impairment in elderly schizophrenia and Alzheimer's disease in the mild cognitive impairment stage

We compared indices of the revised version of the Wechsler Memory Scale (WMS-R) and scaled scores of the five subtests of the revised version of the Wechsler Adult Intelligence Scale (WAIS-R) in 30 elderly schizophrenia (ES) patients and 25 Alzheimer's disease (AD) patients in the amnestic mild cognitive impairment (aMCI) stage (AD-aMCI). In the WMS-R, attention/concentration was rated lower and delayed recall was rated higher in ES than in AD-aMCI, although general memory was comparable in the two groups. In WAIS-R, digit symbol substitution, similarity, picture completion, and block design scores were significantly lower in ES than in AD-aMCI, but the information scores were comparable between the two groups. Delayed recall and forgetfulness were less impaired, and attention, working memory and executive function were more impaired in ES than in AD-aMCI. These results should help clinicians to distinguish ES combined with AD-aMCI from ES alone.

Factors associated with response to clozapine in schizophrenia: a review

BACKGROUND

Clozapine has been serving as the gold standard medication for patients with treatment-resistant schizophrenia who failed to respond to other antipsychotics. However, factors affecting response to this medication have not been comprehensively reviewed recently.

METHODS

In order to find factors associated with response to clozapine in schizophrenia, a literature search was conducted using PubMed through January 2011 with keywords of clozapine, response, and schizophrenia. Cross-referencing of relevant articles was also performed. Factors were arbitrarily classified into the following: demographic/clinical, oral dosage/pharmacokinetic, biochemical, (electro)physiological, genetic, imaging, and combinations.

RESULTS

A synthesis from 280 articles indicated that demographic and clinical variables such as high baseline symptoms and low premorbid functioning have not been particularly useful in predicting response to clozapine. Pharmacokinetic evidence points to a threshold clozapine level of 350 ng/ml but in a context of significant inter- as well as intra-individual variability. Pharmacokinetic perspectives appear to have more implication in special situations including poor response, suspected toxicity and nonadherence. A number of laboratory-based studies have reported on many potential candidates for response prediction to clozapine, however, reproducibility, specificity, robustness of the findings, as well as clinical feasibility and cost-effectiveness all pose a significant practical challenge, in relation with the fact that pathophysiological bases of treatment resistance in schizophrenia largely remain to be elucidated.

CONCLUSIONS

No unequivocal factors to clozapine response were found despite a relatively rich body of the literature, which calls for more works on this important topic. Clozapine level of 350 ng/ml appears to be useful in case of nonresponse.

The paradox of premature mortality in schizophrenia: new research questions

The life expectancy of patients with schizophrenia is reduced by between 15 and 25 years. Those patients dying of natural causes die of the same diseases as in the general population. In 2009 the World Health Organization (WHO) identified underlying global risk factors for mortality in the general population. However, there is little evidence in the literature assessing their validity in those with schizophrenia. The WHO report on global health risks (2009) identifies hypertension, smoking, raised glucose, physical inactivity, overweight and obesity, and high cholesterol as the six leading global mortality risk factors. Currently, there are minimal data on the contribution to mortality that these risk factors make in schizophrenia, and their optimum management. Both short and long-term studies are needed to address these gaps. New research has raised important questions about risk balance with regards to ideal body mass, with some studies showing that being overweight is associated with lower all-cause mortality and lower suicide rates. Cardiorespiratory fitness is being recognized as a more powerful predictor of mortality than smoking, hypertension or diabetes in men. However, there are virtually no published data on assessment of fitness levels in schizophrenia. New studies have raised concerns about the quality of physical care for patients with schizophrenia, which is another important avenue of future research. A greater biological understanding of the relationship between these disorders and schizophrenia would inform clinical practice. Low birth weight has been associated with increased risk for schizophrenia, and it will be important to explore this risk factor for both physical and mental health outcomes.

Are there modifiable risk factors which will reduce the excess mortality in schizophrenia?

The 2009 World Health Organization report on global health risks identifies hypertension, smoking, raised glucose, physical inactivity, obesity and dyslipidaemia, in that order, as being the top six modifiable global mortality risk factors. Patients with schizophrenia have high levels of all these risk factors. There are a small number of studies showing that interventions can improve these, but prospective long-term studies are not available to show their impact on mortality. A number of studies are now supporting the view that patients with schizophrenia may be dying prematurely as they are not gaining access to or receiving the same medical care as the general population. The literature now suggests that low cardiorespiratory fitness and muscle strength are among the strongest predictors of all-cause mortality in the general population. Smoking is still one of the largest risk factors for premature all-cause mortality. The literature supports the thesis that lifestyle intervention programmes addressing exercise, smoking cessation and compliance with medication are likely to have significant impact on mortality in schizophrenia. It will be important to ensure that all patients with schizophrenia have advocates to ensure appropriate treatment and avoid prejudice, and to establish fitness standards in schizophrenia.

Cancer and schizophrenia: is there a paradox?

People with schizophrenia are more likely to die prematurely than the general population from both suicide and physical ill health. Published studies examining the incidence of cancer in schizophrenia patients report increased, reduced or similar incidence compared with the general population. Older studies tended to report lower incidence rates which fuelled speculation as to the biological and other mechanisms for this protective effect. Furthermore, mortality rates in patients with schizophrenia appear higher than expected. We undertook a non-systematic review of published data to give an overview for these variable findings and illustrate methodological confounders by highlighting a systematic review of breast cancer studies.

Favorable mortality profile of naltrexone implants for opiate addiction

Several reports express concern at the mortality associated with the use of oral naltrexone for opiate dependency. Registry controlled follow-up of patients treated with naltrexone implant and buprenorphine was performed. In the study, 255 naltrexone implant patients were followed for a mean (+/- standard deviation) of 5.22 +/- 1.87 years and 2,518 buprenorphine patients were followed for a mean (+/- standard deviation) of 3.19 +/- 1.61 years, accruing 1,332.22 and 8,030.02 patient-years of follow-up, respectively. The crude mortality rates were 3.00 and 5.35 per 1,000 patient-years, respectively, and the age standardized mortality rate ratio for naltrexone compared to buprenorphine was 0.676 (95% confidence interval = 0.014 to 1.338). Most sex, treatment group, and age comparisons significantly favored the naltrexone implant group. Mortality rates were shown to be comparable to, and intermediate between, published mortality rates of an age-standardized methadone treated cohort and the Australian population. These data suggest that the mortality rate from naltrexone implant is comparable to that of buprenorphine, methadone, and the Australian population.

Systematic reviews of categorical versus continuum models in psychosis: evidence for discontinuous subpopulations underlying a psychometric continuum. Implications for DSM-V, DSM-VI, and DSM-VII

Diagnostic systems, phenotype models, and theories of etiology incorporate propositions on the underlying nature of psychosis and schizophrenia phenotypes. These propositions, whether implicit or explicit, are that the distributions of the phenotypes, or the phenotype experiences themselves, are dimensional or categorical. On one hand, evidence on the epidemiology of schizophrenia phenotypes suggests symptom phenotypes may not be bound by conventional diagnostic thresholds but instead may blend imperceptibly with subclinical, statistically frequent experience, supporting continuum viewpoints. On the other hand, evidence on the population structure suggests a latent categorical structure; the population may be composed of two types of people. However, both sets of evidence are beset by methodological limitations that point unequivocally to the need to move beyond current diagnostic conceptualizations, observation, and anamnesis of psychosis, and toward responsive and scientifically refutable formulations of schizophrenia.

Effect of antipsychotic treatment on Insulin-like Growth Factor-1 and cortisol in schizophrenia: a longitudinal study

Neurodevelopmental pathogenesis of schizophrenia might be mediated by abnormalities in Insulin-like Growth Factor-1 (IGF-1). Developmental disturbances like obstetric complications, by themselves, as well as through the resultant hypercortisolemia due to hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, can lead to deficient IGF-1 level. The relevance of IGF-1-Cortisol interactions in schizophrenia, especially in the context of antipsychotic treatment, is yet to be explored. In this study, thirty-three antipsychotic-naïve schizophrenia patients (13-men) were examined for serum IGF-1 and cortisol levels at baseline and after 3months of antipsychotic treatment. For baseline analyses, the patients were compared with 33 healthy controls matched for age, sex, socio-economic status, and physical activity. Symptoms were assessed using Scale for Assessment of Positive Symptoms (SAPS) and Scale for Assessment of Negative Symptoms (SANS). At baseline, schizophrenia patients had significantly lower levels of IGF-1 [t=4.6; p<0.0001] and higher levels of cortisol [t=3.9; p=0.0002] in comparison with healthy controls. Following treatment, IGF-1 level increased significantly [t=4.5; p<0.0001] whereas cortisol decreased significantly [t=2.5; p=0.02] in patients. There was a significant positive correlation between magnitude of increase in IGF-1 level and the magnitude of reduction in cortisol level [r=0.52; p=0.002]. Also, the greater the increase in IGF-1 the greater was the reduction in SAPS score [r=0.39; p=0.02]. Our study findings demonstrate that antipsychotic treatment can result in significant elevation of serum IGF-1 possibly mediated by reduction in cortisol levels. These observations suggest a possible link between HPA axis abnormalities and IGF-1 deficits in the neurodevelopmental pathogenesis of schizophrenia.

Antisaccade performance in schizophrenia patients, their first-degree biological relatives, and community comparison subjects: data from the COGS study

The antisaccade task is a widely used technique to measure failure of inhibition, an important cause of cognitive and clinical abnormalities found in schizophrenia. Although antisaccade performance, which reflects the ability to inhibit prepotent responses, is a putative schizophrenia endophenotype, researchers have not consistently reported the expected differences between first-degree relatives and comparison groups. Schizophrenia participants (n=219) from the large Consortium on the Genetics of Schizophrenia (COGS) sample (n=1078) demonstrated significant deficits on an overlap version of the antisaccade task compared to their first-degree relatives (n=443) and community comparison subjects (CCS; n=416). Although mean antisaccade performance of first-degree relatives was intermediate between schizophrenia participants and CCS, a linear mixed-effects model adjusting for group, site, age, and gender found no significant performance differences between the first-degree relatives and CCS. However, admixture analyses showed that two components best explained the distributions in all three groups, suggesting two distinct doses of an etiological factor. Given the significant heritability of antisaccade performance, the effects of a genetic polymorphism is one possible explanation of our results.

Are cervical cancer screening rates different for women with schizophrenia? A Manitoba population-based study

CONTEXT

Barriers to cervical cancer screening (Pap tests) may exist for women experiencing schizophrenia.

DESIGN

This study analyzed healthcare records of all women in the province of Manitoba, Canada to: (a) compare cervical cancer screening rates of women with and without schizophrenia; and (b) determine factors associated with screening uptake.

SETTING

This study took place in Manitoba, Canada, utilizing anonymized universal administrative data in the Population Health Research Data Repository at the Manitoba Centre for Health Policy.

PARTICIPANTS

All females aged 18-69 living in Manitoba December 31, 2002, excluding those diagnosed with invasive or in situ cervical cancer in the study period or previous 5 years.

MAIN OUTCOME

To determine factors associated with Papanicolaou (Pap) test uptake (1+ Pap test in 3 years, 2001/02-2003/04), logistic regression modeling included: diagnosis of schizophrenia, age, region, average household income, continuity of care (COC), presence of major physical comorbidity. Good COC was defined as at least 50% of ambulatory physician visits from the same general/family practitioner within two years.

RESULTS

Women with schizophrenia (n=3220) were less likely to have a Pap test (58.8% vs. 67.8%, p<.0001) compared to all other women (n=335 294). In the logistic regression, a diagnosis of schizophrenia (aOR=0.70, 95% CI 0.65-0.75); aged 50+, and living in a low-income area or the North decreased likelihood; good continuity of care (aOR 1.88, 95% CI 1.85-1.91) and greater physical comorbidity (1.21, 95% CI 1.04-1.41) increased likelihood.

CONCLUSION

Women with schizophrenia are less likely to receive appropriate cervical cancer screening. Since good continuity of care by primary care physicians may mitigate this, psychiatrists should consider assisting in ensuring screening uptake.

Telomere length and pulse pressure in newly diagnosed, antipsychotic-naive patients with nonaffective psychosis

INTRODUCTION

Recent studies suggest that in addition to factors such as treatment side effects, suicide, and poor health habits, people with schizophrenia may have an increased risk of diabetes prior to antipsychotic treatment. Diabetes is associated with an increased pulse pressure (PP) and a shortened telomere. We tested the hypothesis that prior to antipsychotic treatment, schizophrenia and related disorders are associated with a shortened telomere, as well as an increased PP.

METHODS

Telomere content (which is highly correlated with telomere length) and PP were measured in newly diagnosed, antipsychotic-naive patients with schizophrenia and related disorders on first clinical contact and in matched control subjects. Both groups were also administered an oral glucose tolerance test.

RESULTS

Compared with control subjects, the patients with psychosis had decreased telomere content and an increased PP. As previously reported, they also had increased glucose concentrations at 2 hours. These differences could not be attributed to differences in age, ethnicity, smoking, gender, body mass index, neighborhood of residence, socioeconomic status, aerobic conditioning, or an increased cortisol concentration in the psychotic subjects.

DISCUSSION

These results suggest that prior to antipsychotic use, nonaffective psychosis is associated with reduced telomere content and increased PP, indices that have been linked to an increased risk of diabetes and hypertension.

Does executive function explain the IQ-mortality association? Evidence from the Canadian study on health and aging

OBJECTIVE

To assess the robustness of the association between intelligence quotient (IQ) and mortality in older adults and to examine whether or not the association can be explained by more specific cognitive processes, including individual differences in executive functioning.

METHODS

We examined the associations among Full Scale IQ, individual IQ subtest scores, and 10-year mortality among older community-dwelling, adult participants in the Canadian Study of Health and Aging, who were verified as disease and cognitive-impairment free at baseline via comprehensive medical and neurological evaluation (n = 516). Survival analysis including Cox proportional hazards regression models were used to examine mortality risk as a function of Full Scale IQ and its specific subcomponents.

RESULTS

An inverse association was found between IQ and mortality, but this did not survive adjustment for demographics and education. The association between IQ and mortality seemed to be predominantly accounted for by performance on one specific IQ subtest that taps executive processes (i.e., Digit Symbol (DS)). Performance on this subtest uniquely and robustly predicted mortality in both unadjusted and adjusted models, such that a 1-standard deviation difference in performance was associated with a 28% change in risk of mortality over the 10-year follow-up interval in adjusted models.

CONCLUSIONS

The association between IQ and mortality in older adults may be predominantly attributable to individual differences in DS performance.