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Featured researches published by Cenk Tek.


Schizophrenia Research | 2003

An open-labeled trial of adjunctive donepezil for cognitive impairments in patients with schizophrenia.

Robert W. Buchanan; Ann Summerfelt; Cenk Tek; James M. Gold

A pilot study was conducted to examine if donepezil could enhance cognitive function in patients with schizophrenia. Fifteen subjects who were on stable olanzapine treatment were entered into a 6-week open-labeled trial of donepezil. Subjects received baseline and end-of-study P50 and neuropsychological assessments. Donepezil treatment resulted in significant improvement in manual dexterity. There were moderate improvements in verbal recall memory and visual memory and processing speed, with smaller changes in P50 and verbal recognition memory. There was no effect on an attention measure. There were no changes in either positive or negative symptoms. These results suggest that cholinergic tone modulation may enhance selective behavioral functions in patients with schizophrenia, but further study is required to delineate the full extent of the potential benefit of this approach.


Schizophrenia Research | 2007

A pilot study of a weight management program with food provision in schizophrenia

Michel Jean-Baptiste; Cenk Tek; Ellen Liskov; Umesh Rao Chakunta; Sarah S. Nicholls; Akm Q. Hassan; Kelly D. Brownell; Bruce E. Wexler

Obesity is a serious medical problem that disproportionately affects people with severe mental illness. Behavioral strategies aimed at lifestyle modification have proven effective for weight loss in general population but have not been studied adequately among persons with schizophrenia. We have conducted a randomized controlled pilot trial of an established weight loss program, modified for this specific population, and supplemented with a novel food replacement program, as well as practical, community based teaching of shopping and preparing healthy food. The program not only arrested weight gain, and produced meaningful weight loss, but also weight loss continued 6 months after the intervention is completed. Cognitive impairment had no bearing to the extent a participant benefited from the program. As a conclusion, well designed simple behavioral programs can produce lasting weight loss for patients with schizophrenia and comorbid obesity, improve metabolic indices, and possibly decrease significant medical risks associated with obesity.


Schizophrenia Research | 2011

Insomnia is frequent in schizophrenia and associated with night eating and obesity

Laura B. Palmese; Pamela C. DeGeorge; Joseph C. Ratliff; Vinod H. Srihari; Bruce E. Wexler; Andrew D. Krystal; Cenk Tek

BACKGROUND Sleep difficulties are common in schizophrenia, however these complaints are often overshadowed by more prominent clinical concerns. The point prevalence of insomnia in this population is not well documented. Poor sleep is associated with lower quality of life, impaired cognition, and weight gain. OBJECTIVES The objectives of this study are to evaluate the prevalence of insomnia in schizophrenia and to explore the relationship of sleep to cognition, quality of life, and clinical variables. METHOD 175 outpatients with schizophrenia or schizoaffective disorder were assessed for insomnia. Participants were evaluated for sleep difficulties, sleep patterns, body mass index, and psychiatric symptoms. Participants were also administered a brief cognitive assessment of processing speed. RESULTS 44% of the sample currently met the criteria for clinical insomnia. An additional 4% were successfully treated with medications. Insomnia was associated with depression and was an independent predictor of lower quality of life. Insomnia was also associated with high rates of night eating and patients with severe insomnia were significantly more obese. The type of antipsychotic did not account for the difference in body mass index. No difference between group means in cognition was detected, although those with severe insomnia did perform least well. CONCLUSION Clinical insomnia in outpatients with schizophrenia is highly prevalent and has a negative impact on quality of life and psychiatric symptoms. This study offers additional support to the association between poor sleep and higher weight, as well as indicating a potential link to night eating in this population. Assessment for sleep difficulties should be a routine part of clinical care.


Schizophrenia Research | 2011

Cardiovascular risk in a first-episode psychosis sample: a ‘critical period’ for prevention?

Vivek H. Phutane; Cenk Tek; Lydia Chwastiak; Joseph C. Ratliff; Banu Ozyuksel; Scott W. Woods; Vinod H. Srihari

OBJECTIVE Studies in first episode psychosis samples about status of cardiovascular risk factors have shown discordant results. We aimed to determine the 10-year risk of developing coronary heart disease in a sample of first episode psychosis patients referred to an early intervention clinic and compared the same with age, gender, and race matched controls from the U.S. National Health and Nutrition Examination Survey (NHANES). METHOD We conducted a cross-sectional analysis of baseline data of 56 subjects enrolled in first episode psychosis clinic from April 2006 to January 2010. This sample was compared with age, gender, and race matched 145 individuals drawn from NHANES 2005-2006 database. Sociodemographic and clinical variables were collected. Physical examination including laboratory evaluation was used to screen for common medical illnesses. The 10-year risk of developing coronary heart disease was calculated by using a tool developed by the National Cholesterol Education Program (NCEP-ATP III). RESULTS There were elevated rates of smoking (46%) and hypertension (11%) albeit statistically significant differences from the control could not be demonstrated for these measures or weight, body mass index, or total or HDL cholesterol, fasting plasma glucose, status of diabetes and impaired fasting plasma glucose, HbA1C level. The 10-year median (range) risk of developing coronary heart disease in patients and controls was 1 (0-5)% and 0 (0-9)% respectively. The difference was not statistically significant. CONCLUSIONS First episode psychosis patients do not present with significantly higher cardiovascular risk than age and race-matched controls despite clinically significant prevalence of individual risk factors. This sample presents an opportunity for early intervention for the primary prevention of cardiovascular morbidity and mortality.


Early Intervention in Psychiatry | 2016

Antipsychotic‐induced weight gain in first‐episode psychosis patients: a meta‐analysis of differential effects of antipsychotic medications

Cenk Tek; Suat Kucukgoncu; Sinan Guloksuz; Scott W. Woods; Vinod H. Srihari; Aniyizhai Annamalai

AIM The first-episode psychosis (FEP) represents a critical period to prevent cardiovascular and metabolic morbidity decades later. Antipsychotic (AP)-induced weight gain is one modifiable factor in this period. The purpose of this study is to conduct a meta-analysis of AP-induced weight and body mass index (BMI) change in FEP. METHODS A comprehensive literature search identified 28 articles that reported data on AP-specific weight or BMI change in FEP. We conducted a meta-analysis of short- and long-term mean weight and BMI differences between placebo and AP medications. We also performed subgroup and meta-regression analysis to examine weight, BMI outcomes and their relationship with location (Asian vs. Western), sponsorship and baseline weight and BMIs. RESULTS Compared to placebo, AP-caused mean weight gain was 3.22 kg and 1.4 points BMI in the short-term, and 5.30 kg and 1.86 points BMI in the long term. Clinically significant weight gain risk increased about twofold with AP use. Weight gain was associated with duration of AP use. AP medications were associated with more weight gain in Western samples as opposed to Asian samples. Most AP medications were associated with significant body weight gain and BMI increase in FEP patients, except for ziprasidone. Olanzapine and clozapine caused the highest weight gain compared to placebo. CONCLUSION Except for ziprasidone, most AP medications were associated with body weight gain and BMI increase in FEP patients. Early and continuing effects of various AP medications on weight gain and BMI increase should be taken into consideration by clinicians.


Psychosomatics | 2013

Obese Schizophrenia Spectrum Patients Have Significantly Higher 10-Year General Cardiovascular Risk and Vascular Ages than Obese Individuals without Severe Mental Illness

Joseph C. Ratliff; Laura B. Palmese; Erin L. Reutenauer; Vinod H. Srihari; Cenk Tek

BACKGROUND Individuals with schizophrenia have a life expectancy that is 20 years less than the general population, along with high rates of obesity and cardiovascular disease (CVD) mortality. OBJECTIVE This study assessed the 10-year general CVD risk and vascular ages of 106 obese schizophrenia spectrum patients and 197 demographically matched obese controls without severe mental illness (SMI) from the National Health and Nutrition Examination Survey (NHANES). METHODS Vascular age and general CVD risk were calculated using the Framingham global CVD calculator, which incorporates age, sex, total and HDL cholesterol levels, systolic blood pressure, smoking status, and diabetes or hypertension treatment. RESULTS Obese schizophrenia spectrum patients had a mean vascular age that was 14.1 years older than their mean actual age, whereas obese NHANES participants had only a 6.7-year difference. The probability of experiencing a CVD event within the next 10 years was 10.7% for obese patients and 8.5% for obese NHANES participants. CONCLUSION These findings suggest that schizophrenia spectrum patients experience increased metabolic risk independent of weight. Primary care clinicians can utilize general CVD risk and vascular age scores to communicate metabolic risk more easily and to help make treatment decisions.


Obesity | 2010

Association of prescription H1 antihistamine use with obesity: results from the National Health and Nutrition Examination Survey.

Joseph C. Ratliff; Jessica A. Barber; Laura B. Palmese; Erin L. Reutenauer; Cenk Tek

The incidence of obesity in the United States has reached epidemic proportions. Previous research has shown several medications exert noticeable effects on body‐weight regulation. Histamine‐1 (H1) receptor blockers commonly used to alleviate allergy symptoms are known to report weight gain as a possible side effect. Therefore, we investigated the association between prescription H1 antihistamine use and obesity in adults using data from the 2005–2006 National Health and Nutrition Examination Survey (NHANES). Adults taking prescription H1 antihistamines were matched by age and gender with controls and compared on the basis of body measurements, plasma glucose, insulin concentrations, and lipid levels. Prescription H1 antihistamine users had a significantly higher weight, waist circumference, and insulin concentration than matched controls. The odds ratio (OR) for being overweight was increased in prescription H1 antihistamine users. H1 antihistamine use may contribute to the increased prevalence of obesity and the metabolic syndrome in adults given these medications are also commonly used as over‐the‐counter remedies.


Psychiatric Services | 2015

First-Episode Services for Psychotic Disorders in the U.S. Public Sector: A Pragmatic Randomized Controlled Trial

Vinod H. Srihari; Cenk Tek; Suat Kucukgoncu; Vivek H. Phutane; Nicholas J K Breitborde; Jessica Pollard; Banu Ozkan; John R. Saksa; Barbara Walsh; Scott W. Woods

OBJECTIVE This study sought to determine the effectiveness of a comprehensive first-episode service, the clinic for Specialized Treatment Early in Psychosis (STEP), in an urban U.S. community mental health center by comparing it with usual treatment. METHODS This pragmatic randomized controlled trial enrolled 120 patients with first-episode psychosis within five years of illness onset and 12 weeks of antipsychotic exposure. Referrals were mostly from inpatient psychiatric units, and enrollees were randomly allocated to STEP or usual treatment. Main outcomes included hospital utilization (primary); the ability to work or attend age-appropriate schooling-or to actively seek these opportunities (vocational engagement); and general functioning. Analysis was by modified intent to treat (excluding only three who withdrew consent) for hospitalization; for other outcomes, only data for completers were analyzed. RESULTS After one year, STEP participants had less inpatient utilization compared with those in usual treatment: no psychiatric hospitalizations, 77% versus 56% (risk ratio [RR]=1.38, 95% confidence interval [CI]=1.08-1.58); mean hospitalizations, .33±.70 versus .68±.92 (p=.02); and mean bed-days, 5.34±13.53 versus 11.51±15.04 (p=.05). For every five patients allocated to STEP versus usual treatment, one additional patient avoided hospitalization over the first year (number needed to treat=5; CI=2.7-26.5). STEP participants also demonstrated better vocational engagement (91.7% versus 66.7%; RR=1.40, CI=1.18-1.48) and showed salutary trends in global functioning measures. CONCLUSIONS This trial demonstrated the feasibility and effectiveness of a U.S. public-sector model of early intervention for psychotic illnesses. Such services can also support translational research and are a relevant model for other serious mental illnesses.


Comprehensive Psychiatry | 2012

The effect of dietary and physical activity pattern on metabolic profile in individuals with schizophrenia: a cross-sectional study

Joseph C. Ratliff; Laura B. Palmese; Erin L. Reutenauer; Ellen Liskov; Carlos M. Grilo; Cenk Tek

OBJECTIVE With the rate of obesity on the rise worldwide, individuals with schizophrenia represent a particularly vulnerable population. The aim of this study was to assess the metabolic profile of individuals with schizophrenia in relation to dietary and physical activity habits compared with healthy controls. METHODS Dietary and physical activity habits of 130 individuals with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis of schizophrenia or schizoaffective disorder were compared with 250 body mass index-, age-, and sex-matched and racially matched controls from the 2005-2008 National Health and Nutrition Examination Surveys using a 24-hour diet recall and a self-report physical activity questionnaire. RESULTS Individuals with schizophrenia had significantly higher levels of glycosylated hemoglobin and insulin compared with matched controls. In addition, these individuals had an increased waist circumference and diastolic blood pressure than did the comparison group. Daily energy intake was not different between groups; however, individuals with schizophrenia consumed significantly greater amounts of sugar and fat. Individuals with schizophrenia reported engaging in moderate physical activity less frequently compared with the National Health and Nutrition Examination Surveys group, but there was no difference in reported vigorous physical activity. CONCLUSIONS These findings suggest that the dietary and physical activity habits of individuals with schizophrenia contribute to an adverse metabolic profile. Increased opportunities for physical activity and access to healthy foods for individuals with schizophrenia may ease the burden of disease.


Journal of Nervous and Mental Disease | 2001

Summer birth and deficit schizophrenia in Nithsdale, Scotland.

Cenk Tek; Brian Kirkpatrick; Ciara Kelly; Robin G. McCreadie

Patients with deficit schizophrenia differ from other people with schizophrenia relative to course of illness, treatment response, and neurobiological correlates. An association between deficit schizophrenia and summer birth, in contrast to the winter birth risk factor associated with schizophrenia as a whole, has also been reported. We attempted to replicate the association between summer birth and deficit schizophrenia by using data from a prevalence survey in Nithsdale in southwest Scotland, in which all patients with schizophrenia in Nithsdale were identified and 87% were interviewed directly. Deficit schizophrenia was associated with summer birth, defined as birth in June/July/August (p < .02), June/July (p < .02), or July/August (p < .03). The association with summer birth is consistent with other evidence that patients with deficit schizophrenia have a pathophysiology that differs in some ways from that of other patients with schizophrenia.

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