• Korean Journal of Biological Psychiatry
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• v.23 no.4
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• pp.179-184
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• 2016

Objectives This study was conducted to investigate the possibility of neurological soft signs as an endophenotype for schizophrenia by examining neurological soft signs in patients, their unaffected siblings and normal comparison subjects. Methods The study sample consisted of 32 patients, 25 of their unaffected siblings and 30 normal comparison subjects. Neurological soft signs were evaluated using the Cambridge Neurological Inventory Part 2. soft sign assessment. Results The patients were significantly more impaired than normal comparison subjects (p = 0.047) on primitive reflex. The patients were significantly more impaired than siblings (p = 0.004) and normal comparison subjects (p = 0.021) on motor coordination. The siblings performed better on sensory integration than the patients (p = 0.020) and normal comparison subjects (p = 0.036). Conclusions This study suggests that neurological soft signs might be a potential biomarker for schizophrenia, but might not be an endophenotype for schizophrenia.

• Korean Journal of Biological Psychiatry
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• v.25 no.1
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• pp.9-15
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• 2018

Objectives This study intended to identify the deficits of cognitive control among patients with bipolar I disorder and their first-degree relatives, and identify the possibility of cognitive control as an endophenotype of bipolar disorder. Methods The study included three groups: euthymic states patients with bipolar I disorder (n = 55), unaffected first-degree relatives of probands with bipolar I disorder (n = 30), and a healthy control group (n = 51), that was matched on age, sex, and years of education. The AX version of the continuous performance test (CPT) was used to examine cognitive control. Error rate, correct response times of each subsets (AX, BX, AY, BY), and d' as an indication of accuracy sensitivity index were calculated. Psychopathology, intelligence, and psychomotor speed were also assessed. Results Patients with bipolar I disorder showed significantly worse error rates in the AX (p = 0.01) and BX (p = 0.02) subsets and d' (p = 0.05) than the others. They also showed more delayed correct response times than the healthy control group and first-degree relatives in all subsets (p < 0.01). But first-degree relatives showed neither high error rates nor delayed correct response times than healthy control group. Conclusions These findings suggest that cognitive control is impaired in bipolar I disorder but less likely to be an endophynotype of bipolar I disorder.

• Korean Journal of Biological Psychiatry
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• v.9 no.1
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• pp.25-33
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• 2002

Serotonin transporter(5-HTT) is one of the major action site of antidepressants in neuronal cells. According to the recent studies, it is known that the functional polymorphism in the promoter region of the 5-HTT gene(5-HTT linked polymorphism repetitive element in promoter region, 5-HTTLPR) is associated with antidepressant responsiveness, and the distributions of 5-HTTLPR is various among the different populations. Our preliminary study suggested that it is possible to measure the endophenotype of 5-HTTLPR genotype by examining the pharmacodynamic research of the 5-HTT in platelet membranes. However, there are limitations to predicting the antidepressant responsiveness only from the endophenotypic characteristics of 5-HTT gene promoter polymorphism, and therefore we propose to use the pharmacogenomic methods for overcoming these limitations. We found that the significant correlations existed among the genetic polymorphisms of biogenic amine transporters whose structure and characteristics are similar to the 5-HTT, and the predictable odds ratio of antidepressant responsiveness are increased significantly by combining the effect with other associated polymorphisms, compared to the effect of 5-HTT promoter polymorphism only. These results support the hypothesis that antidepressant treatment has to be individualized according to the genetic and ethnic background of depressed patients. It would be possible to develope the evaluation tools to predict the antidepressant responsiveness and its side effect profile, if scientists reveal the genes related to the action mechanism as well as the metabolism of antidepressants so as to discover the interaction of those genes and contribution of endogenotypes toward antidepressant responsiveness.

• Anxiety and mood
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• v.3 no.2
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• pp.69-76
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• 2007

Anorexia nervosa is a physical and psychosocial disorder that occurs most frequently in adolescent girls and young adult women. A decade ago, anorexia nervosa was rare outside of the developed western countries. However, it is now becoming a common clinical problem among young women in Korea. It is not enough to merely focus on relieving patients from the symptoms of "not eating," which is a practice that has been adopted by some forms of hospital care. The evidence base to guide treatment is limited. Nevertheless, there is the hope that a better understanding of the factors that play a role in the initiation and maintenance of disordered eating behaviors may be lead to more sophisticated treatments. This review aims to look beyond the overt "not eating" phenotype of anorexia nervosa and considers eating disorder endophenotypes based on Treasure's model. The first part of the review sets the basis for a framework of potential eating disorder endophenotypes. A description of the evidence of disordered eating behaviors as well as the clinical and psychopathological features associated with the central control of appetite follow. Finally, we describe how endophenotypes can be translated into treatments.

• Korean Journal of Biological Psychiatry
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• v.18 no.1
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• pp.15-24
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• 2011

Mood disorder is unlikely to be a disease of a single brain region or a neurotransmitter system. Rather, it is now generally viewed as a multidimensional disorder that affects many neural pathways. Growing neuroimaging evidence suggests the anterior cingulate-pallidostriatal-thalamic-amygdala circuit as a putative cortico-limbic mood regulating circuit that may be dysfunctional in mood disorders. Brain-imaging techniques have shown increased activation of mood-generating limbic areas and decreased activation of cortical areas in major depressive disorder(MDD). Furthermore, the combination of functional abnormalities in limbic subcortical neural regions implicated in emotion processing together with functional abnormalities of prefrontal cortical neural regions probably result in the emotional lability and impaired ability to regulate emotion in bipolar disorder. Here we review the biological correlates of MDD and bipolar disorder as evidenced by neuroimaging paradigms, and interpret these data from the perspective of endophenotype. Despite possible limitations, we believe that the integration of neuroimaging research findings will significantly advance our understanding of affective neuroscience and provide novel insights into mood disorders.

• Korean Journal of Biological Psychiatry
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• v.24 no.4
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• pp.225-234
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• 2017

Objectives Local gyrification reflects the early neural development of cortical connectivity, and is regarded as a potential neural endophenotype in psychiatric disorders. Several studies have suggested altered local gyrification in patients with bipolar I disorder (BD-I). The purpose of the present study was to investigate the alterations in the cortical gyrification of whole brain cortices in patients with BD-I. Methods Twenty-two patients with BD-I and age and sex-matched 22 healthy controls (HC) were included in this study. All participants underwent T1-weighted structural magnetic resonance imaging (MRI). The local gyrification index (LGI) of 66 cortical regions were analyzed using the FreeSurfer (Athinoula A. Martinos Center for Biomedical Imaging). One-way analysis of covariance (ANCOVA) was used to analyze the difference of LGI values between two groups adjusting for age and sex as covariates. Results The patients with BD-I showed significant hypogyria in the left pars opercularis (uncorrected-p = 0.049), the left rostral anterior cingulate gyrus (uncorrected-p = 0.012), the left caudal anterior cingulate gyrus (uncorrected-p = 0.033). However, these findings were not significant after applying the multiple comparison correction. Severity or duration of illness were not significantly correlated with LGI in the patients with BD-I. Conclusions Our results of lower LGI in the anterior cingulate cortex and the ventrolateral prefrontal cortex in the BD-I group implicate that altered cortical gyrification in neural circuits involved in emotion-processing may contribute to pathophysiology of BD-I.

• Korean Journal of Biological Psychiatry
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• v.23 no.4
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• pp.193-198
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• 2016

Objectives Obsessive-compulsive disorder (OCD) and schizophrenia have many common clinical and neurocognitive features. However, not all of them share the same underlying mechanism. The aim of this study was to discover evidences that indicate a pathophysiological mechanism specific to OCD by comparing correlations of quantitative electroencephalography (QEEG) patterns and neurocognitive function in patients with OCD and schizophrenia. Methods Resting-state QEEG data of total 265 patients were acquired retrospectively and parameters such as absolute power, relative power and peak frequency were analyzed from the data. Stroop test and Trail Making Test results as well as demographic features were reviewed for this study. The correlation of neurocognitive functions and brain electrical activities in each group were assessed and compared by correlation analysis. Results Compared with the OCD group, the schizophrenia group performed poorly in neurocognitive tests. Mean values of QEEG parameters in patients with OCD and schizophrenia did not show significant differences. Both absolute and relative power of alpha rhythm in central and frontal regions showed significant positive correlation with Stroop test results in OCD patients. Conclusions Findings in this study shows distinctive correlations between frontal executive dysfunction and frontal alpha rhythm in the OCD patients, both of which might be a candidate for endophenotype underlying obsessive rumination.

• Korean Journal of Biological Psychiatry
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• v.21 no.2
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• pp.65-73
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• 2014

Objectives This study aimed to identify the differences and the profiles of cognitive deficits in remitted patients with schizophrenia and first-degree relatives of schizophrenic probands. Methods A total of 26 remitted states of schizophrenia patients were included in the study and the same number of unaffected first-degree relatives of schizophrenic probands and healthy controls were matched for age, sex, years of education. Cognitive function of all participants was measured by using the Digit span test, the Continuous performance test, the Rey auditory & visual learning test, the Complex figure test, the Verbal fluency test, the Wisconsin card sorting test and the Finger tapping test. The effects of subsyndromal symptomatology and general intelligence score were controlled. Results Schizophrenia patients' group showed more significant impairment than other groups in verbal memory (learning, immediate recall, delayed recall), visual memory (copy, immediate recall, delayed recall) and cognitive flexibility domains. The family group and the patient group commonly performed significantly worse than healthy controls in working memory and verbal fluency (category) tests. There were no differences in sustained attention, psychomotor performance. Conclusions Our research shows that the deficit in working memory and verbal fluency could be strong candidates of endophenotypic marker in schizophrenia.

• Korean Journal of Biological Psychiatry
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• v.25 no.4
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• pp.101-109
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• 2018

Objectives According to previous studies, the Chromogranin B (CHGB) gene could be an important candidate gene for schizophrenia which is located on chromosome 20p12.3. Some studies have linked the polymorphism in CHGB gene with the risk of schizophrenia. Meanwhile, smooth pursuit eye movement (SPEM) abnormality has been regarded as one of the most consistent endophenotype of schizophrenia. In this study, we investigated the association between the polymorphisms in CHGB gene and SPEM abnormality in Korean patients with schizophrenia. Methods We measured SPEM function in 24 Korean patients with schizophrenia (16 male, 8 female) and they were divided according to SPEM function into two groups, good and poor SPEM function groups. We also investigated genotypes of polymorphisms in CHGB gene in each group. A logistic regression analysis was performed to find the association between SPEM abnormality and the number of polymorphism. Results The natural logarithm value of signal/noise ratio (Ln S/N ratio) of good SPEM function group was $4.19{\pm}0.19$ and that of poor SPEM function group was $3.17{\pm}0.65$. In total, 15 single nucleotide polymorphisms of CHGB were identified and the genotypes were divided into C/C, C/R, and R/R. Statistical analysis revealed that two genetic variants (rs16991480, rs76791154) were associated with SPEM abnormality in schizophrenia (p = 0.004). Conclusions Despite the limitations including a small number of samples and lack of functional study, our results suggest that genetic variants of CHGB may be associated with SPEM abnormality and provide useful preliminary information for further study.nwhile, smooth pursuit eye movement (SPEM) abnormality has been regarded as one of the most consistent endophenotype of schizophrenia. In this study, we investigated the association between the polymorphisms in CHGB gene and SPEM abnormality in Korean patients with schizophrenia. MethodsZZWe measured SPEM function in 24 Korean patients with schizophrenia (16 male, 8 female) and they were divided according to SPEM function into two groups, good and poor SPEM function groups. We also investigated genotypes of polymorphisms in CHGB gene in each group. A logistic regression analysis was performed to find the association between SPEM abnormality and the number of polymorphism. ResultsZZThe natural logarithm value of signal/noise ratio (Ln S/N ratio) of good SPEM function group was $4.19{\pm}0.19$ and that of poor SPEM function group was $3.17{\pm}0.65$. In total, 15 single nucleotide polymorphisms of CHGB were identified and the genotypes were divided into C/C, C/R, and R/R. Statistical analysis revealed that two genetic variants (rs16991480, rs76791154) were associated with SPEM abnormality in schizophrenia (p = 0.004). ConclusionsZZDespite the limitations including a small number of samples and lack of functional study, our results suggest that genetic variants of CHGB may be associated with SPEM abnormality and provide useful preliminary information for further study.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.16 no.2
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• pp.192-198
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• 2005

Objectives : This review examines the extent of harmonization between the Diagnostic and Statistical Manual (fourth edition) (DSM-IV) attention deficit hyperactivity disorder (ADHD) and International Classification of Diseases (tenth edition) (ICD-10) hyperkinetic disorder (HKD). Methods : PubMed review of the clinical literatures from 1980 to March 2005 was undertaken using the search term of ADHD, HKD, DSM, ICD, diagnostic criteria, algorithm, and validity. Results : There continues to be a substantial difference in the prevalence of ADHD and HKD. Based on the limited studies that directly compare the most recent two algorithms of ADHD and HKD, several implications for clinical practice and research are discussed. Conclusion : To understand further if the criteria for DSM-IV and ICD-10 for ADHD and HKD are converged or not, more researches on the validity of ADHD and HKD subtypes should be undertaken.