• Korean Journal of Biological Psychiatry
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• v.13 no.4
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• pp.267-272
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• 2006

Objectives : Schizophrenia is a clinically heterogenous disease with a strong genetic component. Many studies have suggested that brain-derived neurotrophic factor(BDNF) is involved in the pathophysiology of schizophrenia. This study was performed to determine whether there is an association between BDNF Val66Met polymorphism and schizophrenia. Methods : To identify any genetic predisposition to schizophrenia, we investigated the BDNF Val66Met polymorphism in 106 patients with schizophrenia and 147 normal controls with PCR-RFLP method. Statistical analyses were used to test the association between and BDNF Val66Met genotype and Schizophrenia. Results : No association was found between BDNF Val66Met polymorphism and schizophrenia. No significant differences were found comparing the BDNF genotype distributions according to the age of onset, the number of admission and familial loading in schizophrenia. Conclusion : This result indicates that BDNF Val66Met polymorphism is not associated with schizophrenia. However, further studies with a large number of subjects are needed to confirm whether the BDNF gene is related to schizophrenia.

• Korean Journal of Biological Psychiatry
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• v.26 no.2
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• pp.59-64
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• 2019

Objectives Internet gaming disorder (IGD) is associated with attention deficit/hyperactivity disorder (ADHD) or depression etc. We tried to examine the mediating effects of depression in the relationship between ADHD and IGD. Methods This study was conducted on 2000 people who participated in on-line survey among 14-39 year-old men and women in 2017. And we clarified the relationship among IGD, ADHD, and depression and tested the mediation model. The mean and standard deviation of the main variables were calculated and correlation analysis was performed to confirm the relationship among the main variables. In order to test the mediating effect of depression on the relationship between ADHD and IGD, the structural equation model was implemented using AMOS 21 (IBM). Results There were significant correlations among the variables; IGD, ADHD and depression. Depression had a mediating effect 0.23 (95% confidence interval : 0.17-0.28) in the relationship between IGD and ADHD. Conclusions This study showed that depression can mediate ADHD and IGD. Therefore, the evaluation and management of depression and ADHD should be included in the diagnosis and treatment of IGD.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.32 no.3
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• pp.85-92
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• 2021

Attention-deficit/hyperactivity disorder (ADHD) leads to functional decline in academic performance, interpersonal relationships, and development in school-aged children. Early diagnosis and appropriate intervention can significantly reduce the functional decline caused by ADHD. Currently, there is no established biological marker for ADHD. Some studies have suggested that various indicators from the quantitative electroencephalogram (QEEG) may be useful biological markers for the diagnosis of ADHD. Until the 2010s, theta/beta ratio (TBR) was a biomarker candidate for ADHD that consistently showed high diagnostic value. However, limitations of TBR have recently been reported. Studies have demonstrated that phase-amplitude coupling, especially theta phase-gamma amplitude coupling, are related to cognitive dysfunction and may assist in the diagnosis of ADHD. As yet, the underlying mechanism is not clearly established, and the clinical efficacy of these biomarkers needs to be proven through well-controlled studies. Based on the heterogeneous characteristics of ADHD, subgrouping through QEEG plays a key role in diagnosis and treatment planning. Sophisticated, well-designed studies and meta-analyses are necessary to confirm these findings.

• Journal of the Korean society of biological therapies in psychiatry
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• v.24 no.3
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• pp.129-141
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• 2018

Suicide is a behavior that is intended to cause death by itself and requires medical treatment, resulting in suicidal attempt or completion. Suicide causes loss of life, damages the body, costs a lot of medical expenses, and causes families to fall into sorrow and suffering therefore this suicide is a huge loss to family and society. There have been attempts to reduce and prevent suicide by understanding the mechanism of suicide. The mechanism of suicide can be thought of as psychological mechanism and biological mechanism. In the past, if we considered the psychological and biological mechanisms separately, the development of neuroscience now connects and integrates these two. Psychological factors affect biological factors and biological temperaments also affect perception or thinking about the situation and increase psychological vulnerability. Distant factors in suicidal behavior-such as childhood adversity and family and genetic predisposition-increase the lifetime risk of suicide. They alter the response to stress and other processes through changes in gene expression and regulation of emotional and behavioral characteristics. Distant factors affect the biological system and consequently changes in these systems can increase the risk of suicide. In other words, the distal factor does not directly induce suicidal behavior but rather acts indirectly through developmental or mediating factors. These mediating factors are impulsive aggressive and anxious trait, and chronic use of substances. The mechanism of this disorder is the abnormality of the serotonin system and the abnormality of the lipid level. Proximal factors are associated with the onset of suicide events and include changes in the major neurotransmitter systems, inflammatory changes, and dysfunction of glial cells in the brain. A series of studies, including a variety of research methods and postmortem and in-vivo imaging studies, show the impairment of the serotonergic neurotransmitter system and hypothalamic-pituitary-adrenal axis stress response system for suicidal behavior. These disorders lead to suicidal behavior due to difficulty in cognitive control of mood, pessimism, reactive aggression, abnormality in problem solving abilities, excessive response to negative social signals, severe emotional distress, and cognitive dysregulation of suicidal ideation.

• Korean Journal of Biological Psychiatry
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• v.23 no.2
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• pp.37-40
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• 2016

Treatment-resistant depression (TRD) is a major public health problem. It is estimated that about 30% of patients with major depressive disorder do not show substantial clinical improvement to somatic or psychosocial treatment. Most of studies for TRD have focused on the subjects already known as TRD. Patients with unipolar depressive episodes that do not respond satisfactorily to numerous sequential treatment regimens were included in the TRD studies. Such post hoc experimental design can be regarded only as consequences of having TRD, rather than as causal risk factors for it. Although informative, data derived from such studies often do not allow a distinction to be made between cause and effect. So, we should shift paradigm toward examining the risk for developing TRD in untreated depressed patients. To deal with this problem, untreated depressed patients should be enrolled in the study to identify biological markers for treatment resistance. The peripheral or central biological markers should be explored before starting treatment. Subsequent systematic administration of treatments with appropriate monitoring in the subjects can determine the risk for developing treatment resistance in untreated individuals. Such information could give a cue to improve the initial diagnosis and provide more effective treatment for TRD.

• 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.12 no.2
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• pp.173-180
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• 2005

Purpose:We investigated the effect of menopausal duration on cognitive function using adjunctive hormone replacement therapy(HRT) in postmenopausal women with depression. Method:Twelve postmenopausal women with depressive disorder were enrolled. Six patients having menopausal duration of less than 3 years was assigned to the short duration group and six patients of more than 3 years to the long duration group. Each patient was treated with conjugated equine estrogen(1.25mg) plus medroxyprogesterone(5mg) for 8 weeks. Cognitive performance was measured by the Verbal Memory Test, Visual Memory Test, Trail Making Test, Digit Symbol Test, and Attention Shift Test. The Beck Depression Inventory was used for evaluation of depressed mood. The reproductive hormone levels were also measured. Results:The long duration group showed the lower performance only in Trail Making Test B compared with the short duration group at baseline. After 8 weeks, the long duration group performed significantly better in the Trail Making Test B compared with the short duration group. The differences in change of depressive mood and gonadal hormone level between two groups were not significant. Conclusion:Menopausal duration before HRT may influence the effect of estrogen on cognition in some cognitive domains. This might be related with estrogen receptor hypersensitivity which induced by the longer estrogen deficiency.

• Korean Journal of Biological Psychiatry
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• v.12 no.2
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• pp.151-158
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• 2005

Background:Clozapine is a unique atypical antipsychotic medication. It is considered to be superior, even amongst the newer agents, in treatment-resistant schizophrenia. However, de novo emergence or exacerbation of obsessive-compulsive(OC) symptoms during treatment with clozapine has been reported. We prospectively evaluated 19 cases which newly developed OC symptoms during clozapine treatment and discussed the treatment of OC symptoms induced by it. Methods:We recruited 19 patients(8 males, 11 females) with a DSM-IV diagnosis of schizophrenia and schizoaffective disorder who had developed OC symptoms during clozapine treatment. OC symptoms were assessed using the Padua-ICMA and YBOCS on a monthly basis over three months. Results:Eleven female and eight male patients were enrolled and the average age of patients was 32.8 years. At baseline, no patients showed OC symptoms. Moderate to severe OC symptoms appeared with mean daily dose of 298.68 mg of clozapine. There were no significant differences in improving OC symptoms between the clozapine dose reduction group and the OC treatment group. Conclusion:We noticed the possibility that the appearance of OC symptoms is connected with the effect of clozapine. The clozapine-induced OC symptoms were improved both by reducing clozapine daily doses, and by adding OC treatment drugs. With other atypical antipsychotics now available, to know and treat the side effects of clozapine would be of considerable value, offering clinical guidance in making a decision on treatment-resistant schizophrenia.

• Korean Journal of Biological Psychiatry
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• v.12 no.1
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• pp.13-19
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• 2005

Objective:The purposes of this study were to investigate heart rate variability(HRV) in patients with generalized anxiety disorder(GAD) compared with major depressive disorder in Korea. Methods:Fifty-six GAD patients(20 male and 36 female) was classified into their comorbid psychiatric illness. Among them, Twenty-five patients(10 male and 15 female) who do not have any psychiatric comorbidity were compared with 30 major depressive disorder patients(12 male and 18 female). Clinical symptoms, HRV and MMPI were analysed between two group. Results:Comorbid psychiatric illnesses of GAD were ranked into no diagnosis(44.6%), MDD(32.1%), panic disorder(10.7%), social phobia(5.3%), PTSD(1.7%), OCD(1.7%), MDD+panic disorder(1.7%) and MDD+specific phobia(1.7%). GAD patients showed low functioning in HRV, but degree of decreasing HRV is not so severe compared with MDD patient. Balance of sympathetic and parasympathetic nerve tone is more severely impaired in GAD patients compared with MDD patient. The score of MMPI did not reveal any differences between two groups. Conclusions:The result showed that HRV can differenciate GAD and MDD patients. GAD patients could show decreased HRV functioning, less than MDD patients. But autonomic imbalance could be more severe in GAD than MDD patients.

• Korean Journal of Biological Psychiatry
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• v.22 no.4
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• pp.163-172
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• 2015

Objectives This study was aimed to examine the multidimensional relationship between auditory verbal hallucinations (AVHs) and Positive and Negative Syndrome Scale (PANSS) factors of psychopathology in the patients with schizophrenia. And we explored the differences between assessments to hallucination by the clinicians and patients. Methods 82 patients with schizophrenia who were assessed by the Hamilton Program for Schizophrenia Voices Questionnaire (HPSVQ), Psychotic Symptom Rating Scale-Auditory Hallucination (PSYRATS-AHS), and the PANSS were recruited. Hwang's five-factor model of PANSS, items and total scores of hallucination scales, Kim's and Haddock's factor models of hallucination were applied to examine the correlations between psychopathology and AVHs. AVH-positive patients was 50 in PANSS-HPSVQ group and 24 in PANSS-PSYRATS-AHS. These two groups were separately analyzed. Results Among the five factors of the PANSS, negative and depression/anxiety factors were correlated with the total scores of HPSVQ and PSYRATS-AHS, and positive and autistic preoccupation factors were correlated only with the total score of PSYRATS-AHS. The activation factor was correlated with none of the total scores of HPSVQ/PSYRATS-AHS. These correlation patterns of a total score of HPSVQ/PSYRATS-AHS were same in the emotional factor of HPSVQ and physical factor of PSYRATS-AHS respectively. In the items which showed significant correlations, correlation coefficients of PANSS-PSYRATS-AHS group ranged between 0.406-0.755 and those of PANSS-HPSVQ ranged between 0.283-0.420. Conclusions This study suggested that the psychopathological domains of schizophrenia were differentially correlated with AVHs and the assessment of AVHs by clinicians and patients showed substantial differences which should be integrated into the therapeutic interventions.