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Neurological soft signs might be endophenotype candidates for patients with deficit syndrome schizophrenia

Authors Albayrak Y, Akyol E, Beyazyüz M, Baykal S, Kuloglu M

Received 25 June 2015

Accepted for publication 7 October 2015

Published 29 October 2015 Volume 2015:11 Pages 2825—2831


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 2

Editor who approved publication: Dr Roger Pinder

Yakup Albayrak,1 Esra Soydaş Akyol,2 Murat Beyazyüz,1 Saliha Baykal,1 Murat Kuloglu3

1Department of Psychiatry, Faculty of Medicine, Namik Kemal University, Tekirdag, 2Department of Psychiatry, Yenimahalle Education and Research Hospital, Ankara, 3Department of Psychiatry, Faculty of Medicine, Akdeniz University, Antalya, Turkey

Background: Schizophrenia is a chronic, disabling, disorder that affects approximately 1% of the population. The nature of schizophrenia is heterogeneous, and unsuccessful efforts to subtype this disorder have been made. Deficit syndrome schizophrenia (DS) is a clinical diagnosis that has not been placed in main diagnostic manuals. In this study, we aimed to investigate and compare neurological soft signs (NSS) in DS patients, non-deficit schizophrenia (NDS) patients, and healthy controls (HCs). We suggest that NSS might be an endophenotype candidate for DS patients.
Methods: Sixty-six patients with schizophrenia and 30 HCs were enrolled in accordance with our inclusion and exclusion criteria. The patients were sub-typed as DS (n=24) and NDS (n=42) according to the Schedule for the Deficit Syndrome. The three groups were compared in terms of sociodemographic and clinical variables and total scores and subscores on the Physical and Neurological Examination for Soft Signs (PANESS). Following the comparison, a regression analysis was performed for predictability of total PANESS score and its subscales in the diagnosis of DS and NDS.
Results: The groups were similar in terms of age, sex, and smoking status. The results of our study indicated that the total PANESS score was significantly higher in the DS group compared to the NDS and HC groups, and all PANESS subscales were significantly higher in the DS group than in the HC group. The diagnosis of DS was predicted significantly by total PANESS score (P<0.001, odds ratio =9.48, 95% confidence interval: 0.00–4.56); the synergy, graphesthesia, stereognosis, motor tasks, and ability to maintain posture subscales were found to be significant predictors.
Conclusion: This study confirms that NSS were higher in patients with DS. In addition, we suggest that our results might support the notion of DS as a different and distinct type of schizophrenia. NSS might also be a promising candidate as an endophenotype for DS. However, large sampled, multicentric studies are needed to clarify the place of NSS as an endophenotype in DS.

Keywords: biomarker, psychosis, sign, clinical subtypes of schizophrenia

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