Meram Can Saka

Early Expression of Negative/Disorganized Symptoms Predicting Psychotic Experiences and Subsequent Clinical Psychosis: A 10-Year Study

OBJECTIVE The cognitive and motivational impairments observed in psychotic disorders may reflect early developmental alterations that, when combined with later environmental exposures, may drive the onset of positive psychotic symptoms. The epidemiological predictions of this model were tested. METHOD A longitudinal prospective cohort study (the Early Developmental Stages of Psychopathology Study) was conducted with a representative general population sample of adolescents and young adults from Munich (N=3,021), who were 14-24 years of age at baseline. Sociodemographic factors, environmental exposures, and measures of psychopathology and associated clinical relevance were assessed across three waves, covering a period of up to 10 years, by clinical psychologists using the Composite International Diagnostic Interview. RESULTS Both negative/disorganized and positive psychotic symptoms were frequent (5-year cumulative prevalence rates of around 12%) and occurred in combination more often than predicted by chance. Negative/disorganized symptoms revealed a pattern of sociodemographic associations indicative of developmental impairment, whereas the positive symptoms were associated with environmental exposures such as trauma, cannabis use, and urbanicity. Negative/disorganized symptoms predicted positive symptoms over time, and co-occurrence of positive and negative/disorganized symptoms was predictive of clinical relevance in terms of secondary functional impairment and help-seeking behavior. CONCLUSION The results suggest that the negative/disorganized features associated with psychotic disorder are distributed at the population level and drive the ontogenesis of positive psychotic experiences after exposure to environmental risks, increasing the likelihood of impairment and need for care.

Cortical inhibition in first-degree relatives of schizophrenic patients assessed with transcranial magnetic stimulation

Although cortical inhibition deficit has been shown in schizophrenia patients by transcranial magnetic stimulation (TMS), some controversies remain, possibly due to confounding factors such as medication use and clinical state at the time of assessment. First-degree relatives of schizophrenia patients, who share various degrees of genetic vulnerability with the patients, but are free from confounds related to medication and/or florid psychosis, have not been studied to date. We compared 12 relatives with 14 controls on several paradigms with TMS. Three of the 12 healthy relatives lacked transcallosal inhibition (TI) in one or more of the stimulation levels. There were no significant differences in other parameters. The lack of TI in 25% of the relatives is an important finding that needs to be replicated in larger samples that are heterogeneous in terms of psychosis-proneness.

The effectiveness of intramuscular biperiden in acute akathisia: a double-blind, randomized, placebo-controlled study.

Neuroleptic-induced acute akathisia (NIA) is a distressing condition and an important clinical problem because it is associated with treatment noncompliance and suicidal or impulsive behavior. Anticholinergics are among the treatment options; however, a review of the literature fails to identify a double-blind, randomized, placebo-controlled study of these medications in NIA. In a randomized, double-blind, placebo-controlled design, we studied the effectiveness of intramuscular biperiden (n = 15) or isotonic saline (n = 15) in the treatment of NIA diagnosed with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria. Injections were repeated up to 3 times unless akathisia was completely treated (scored 0 for global akathisia with the Barnes Akathisia Rating Scale). Patients were assessed for akathisia, other movement disorders, and psychiatric symptoms at baseline and 3 times after the first injection at 2-hour intervals. Response was defined as at least a 2-point decline in the global akathisia score. The numbers of responders in the 2 groups were not significantly different (7 and 5 in the biperiden and placebo groups, respectively). The courses of individual items on the Barnes Akathisia Rating Scale were also similar. Our results suggest that intramuscular biperiden should not be considered as a first-line treatment of NIA.

Effects of paliperidone extended release on functioning level and symptoms of patients with recent onset schizophrenia: An open-label, single-arm, flexible-dose, 12-months follow-up study.

Abstract Background: Response to antipsychotic treatment is better in the early stages of schizophrenia. Aims: The primary objective of this non-randomized, single-arm, multicenter clinical trial was to explore the response to treatment and safety of a flexible dose of paliperidone (mean = 6.42 mg/day) in patients with recent onset schizophrenia (< 3 years after the first episode/hospitalization). Methods: Severity of clinical symptoms was evaluated by the Positive and Negative Syndrome Scale (PANSS), functioning was assessed using the Global Assessment of Functioning (GAF) scale and the Personal and Social Performance Scale (PSP). Results: In a total of 85 patients enrolled, 80 patients were eligible. Total PSP score at baseline (50.2 ± 11.6) increased at all visits. Total PSP score was 65.4 ± 12.1 at month 12 (P < 0.001). GAF scores were significantly higher at all visits compared with baseline (P = 0.001). It was 62.4 ± 12.5 with an increase of 42.9% at month 12 (P < 0.001). PANSS Positive and Negative subscales and General psychopathology subscale scores showed significant reductions beginning with month 3 and were 11.9 ± 3.8 (29.3%; P < 0.001), 13.7 ± 5.6 (27.3% P < 0.001) and 27.8 ± 7.1 (23.2%; P < 0.001) at month 12, respectively. Twelve patients (14.3%) had a serious adverse event. The most common adverse events were insomnia (17.9%), nausea (8.3%), akathisia (4.8%), anxiety (4.8%) and depression (4.8%). Body weight values at the end of the study were significantly higher compared with baseline. Conclusion: The present study demonstrates that flexible dose of paliperidone resulted in a significant improvement in functioning and reduction in symptoms in patients with recent onset schizophrenia.

Exploring the Role of Social Anhedonia in the Positive and Negative Dimensions of Schizotypy in a Non-Clinical Sample

INTRODUCTION The present study aimed to investigate the role of social anhedonia, defined as the lack of ability to feel pleasure from interpersonal relationship, in a multidimensional model of schizotypy and to determine the psychometric properties of the Turkish version of Chapmans Revised Social Anhedonia Scale (SAS) in a non-clinical sample. METHODS Second-grade students of Ankara University Medical Faculty were recruited (n=266, Mage=20.28). Confirmatory factor analysis was performed to test schizotypy dimensions. The Cronbachs alpha internal consistency value, test-retest reliability and congruent validity of SAS were calculated. RESULTS The model in which social anhedonia was allowed to load on both schizotypy dimensions fit the data set better than the model in which social anhedonia was allowed to load on negative dimension alone. The internal consistency assessed with Cronbachs alpha was .84, test-retest reliability was r=.76 and the congruent validity of SAS was r=.55. CONCLUSION The results of current study were consistent with those of earlier studies showing that social anhedonia was related to both schizotypy dimensions. Furthermore, the psychometric properties of the Turkish Version of SAS revealed that it is a reliable and valid measurement to assess social anhedonia in a non-clinical population.

Higher schizotypy predicts better metabolic profile in unaffected siblings of patients with schizophrenia

RationaleType 2 diabetes (T2D) is more frequent in schizophrenia (Sz) than in the general population. This association is partly accounted for by shared susceptibility genetic variants.ObjectiveWe tested the hypotheses that a genetic predisposition to Sz would be associated with higher likelihood of insulin resistance (IR), and that IR would be predicted by subthreshold psychosis phenotypes.MethodsUnaffected siblings of Sz patients (n = 101) were compared with a nonclinical sample (n = 305) in terms of IR, schizotypy (SzTy), and a behavioural experiment of “jumping to conclusions”. The measures, respectively, were the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), Structured Interview for Schizotypy-Revised (SIS-R), and the Beads Task (BT). The likelihood of IR was examined in multiple regression models that included sociodemographic, metabolic, and cognitive parameters alongside group status, SIS-R scores, and BT performance.ResultsInsulin resistance was less frequent in siblings (31.7%) compared to controls (43.3%) (p < 0.05), and negatively associated with SzTy, as compared among the tertile groups for the latter (p < 0.001). The regression model that examined all relevant parameters included the tSzTy tertiles, TG and HDL-C levels, and BMI, as significant predictors of IR. Lack of IR was predicted by the highest as compared to the lowest SzTy tertile [OR (95%CI): 0.43 (0.21–0.85), p = 0.015].ConclusionHigher dopaminergic activity may contribute to both schizotypal features and a favourable metabolic profile in the same individual. This is compatible with dopamine’s regulatory role in glucose metabolism via indirect central actions and a direct action on pancreatic insulin secretion. The relationship between dopaminergic activity and metabolic profile in Sz must be examined in longitudinal studies with younger unaffected siblings.

Sosyal Anhedoni'nin Pozitif ve Negatif Şizotipi Boyutlarındaki Yerinin Klinik Olmayan Örneklemde İncelenmesi

Araştırma Makalesi / Research Article ©Copyright 2015 by Turkish Association of Neuropsychiatry Available online at www.noropskiyatriarsivi.com ©Telif Hakkı 2015 Türk Nöropsikiyatri Derneği Makale metnine www.noropskiyatriarsivi.com web sayfasından ulaşılabilir. GİRİŞ Şizotipi ilk olarak, Rado (1) tarafından, psikotik belirtiler gösteren ancak hiçbir zaman şizofreni geliştirmeyen kişilerdeki şizofreni benzeri belirtileri tanımlamak için kullanılmıştır. Meehl’in öncülüğünü yaptığı Kuzey Amerika yaklaşımı, şizotipinin görülmesinde nörogelişimsel bir bozukluğa vurgu yaparak, stres-yatkınlık modeli çerçevesinde; şizofreni geliştirmeye genetik olarak yatkınlıkları olan şizotaksik kişilerin yaklaşık %10’unun yaşamlarının erken dönemlerinde zorlayıcı çevresel deneyimlere maruz kalırlarsa şizofreni geliştirebileceklerini, ancak herhangi bir örselenme yaşamazlarsa sadece şizotipal özellikler göstereceklerini öne sürmüştür (2,3,4). Şizotipinin klinik görünümünün şizofreniye benzediği fikri ise şizotipal özellikleri tanımlamayı ve ölçmeyi amaçlayan çalışmalarda şizofreni boyutlarına benzer boyutların kullanılmasında oldukça etkili olmuştur. Şizotipal özelliklerin çok boyutlu yapısının anlaşılmasının, şizofreni ve şizofreni spektrum bozuklukların etiyolojisinin anlaşılmasına destek olabileceği düşünülmüş (5) ancak, bildirilen çalışmalarda bu boyutların sayı ve içeriği çeşitlilik göstermiştir. Vollema ve van den Bosch, normal örneklemde şizotipinin çok boyutlu yapısını araştıran faktör analitik çalışmaları gözden geçirdiklerinde çoğu çalışmada şizotipinin üç ya da dört boyutlu bir yapıda değerlendirildiğini bildirmişler; ilk boyutun algısal bozulmalar ve büyüsel düşünceleri kapsayan pozitif boyut, ikinci boyutun içe dönüklük ve sosyal–fiziksel anhedoniyi içeren negatif boyut olduğunu belirlemişlerdir (6). Yapısal geçerliği ilk ikisine göre

Evidence for normal cortical inhibition in first-degree relatives of schizophrenic patients: A preliminary report

length of both apical ( wt:994.5 microm, n=6; KO: 600.6 microm, n=4) and basal dendrites (wt: 1268.3 microm, n=6; KO: 906.4 microm, n=4) of pyramidal neurons was significantly reduced in D2 receptor knockout animals. In addition the number of dendritic intersections was reduced (wt: 49.8, n=6; KO: 33.0, n=4). Interestingly, the mean total axonal length was increased in KO animals (wt: 341.1 microm, n=6; KO: 842.3 microm, n=4). These results indicate that the D2 receptor pathway is critically involved in the maturation of parvalbumin positive interneurons and inhibitory transmission in the prefrontal cortex of the mouse.