Boseok Cha

Differential pattern of semantic memory organization between bipolar I and II disorders

Semantic cognition is one of the key factors in psychosocial functioning. The aim of this study was to explore the differences in pattern of semantic memory organization between euthymic patients with bipolar I and II disorders using the category fluency task. Study participants included 23 euthymic subjects with bipolar I disorder, 23 matched euthymic subjects with bipolar II disorder and 23 matched control subjects. All participants were assessed for verbal learning, recall, learning strategies, and fluency. The combined methods of hierarchical clustering and multidimensional scaling were used to compare the pattern of semantic memory organization among the three groups. Quantitative measures of verbal learning, recall, learning strategies, and fluency did not differ between the three groups. A two-cluster structure of semantic memory organization was identified for the three groups. Semantic structure was more disorganized in the bipolar I disorder group compared to the bipolar II disorder. In addition, patients with bipolar II disorder used less elaborate strategies of semantic memory organization than those of controls. Compared to healthy controls, strategies for categorization in semantic memory appear to be less knowledge-based in patients with bipolar disorders. A differential pattern of semantic memory organization between bipolar I and II disorders indicates a higher risk of cognitive abnormalities in patients with bipolar I disorder compared to patients with bipolar II disorder. Exploring qualitative nature of neuropsychological domains may provide an explanatory insight into the characteristic behaviors of patients with bipolar disorders.

Resilience and impulsivity in euthymic patients with bipolar disorder

BACKGROUND Stress plays an important role in the onset and recurrence of bipolar disorder (BD). Resilience is the ability to cope with stress or adversity. Few studies have examined resilience in BD, and this study aimed to investigate the clinical correlates of resilience in euthymic patients with BD. METHODS A total of 62 outpatients with BD type I, II, and not otherwise specified (NOS) who were in remission and 62 healthy individuals matched with the BD group in terms of age and sex were recruited. All participants completed the Connor-Davidson Resilience Scale and Barratt Impulsiveness Scale. A psychiatrist interviewed the subjects to assess clinical characteristics. Multiple linear regression analysis was used to determine factors associated with resilience. RESULTS The BD group had significantly higher levels of impulsivity and lower levels of resilience compared with the control group. Degree of impulsivity, number of depressive episodes, Clinical Global Impression (CGI) scores, and length of education were significantly correlated with resilience. Attention impulsivity, non-planning impulsivity, and number of depressive episodes were associated with low levels of resilience, even when age, sex, length of education, and CGI scores were controlled. LIMITATIONS Because tertiary hospital patients were recruited, the generalizability of the findings is limited. CONCLUSIONS This study shows that low levels of resilience are related to high levels of impulsivity and to an increased number of depressive episodes in euthymic patients with BD. Given the reciprocal relationship between resilience and impulsivity, efforts to enhance resilience and reduce impulsivity may make important contributions to the treatment of patients with BD.

Reasons for desiring death: Examining causative factors of suicide attempters treated in emergency rooms in Korea

BACKGROUND Suicide attempters treated in emergency rooms were studied in order to understand the motives behind this behavior. Disparities between the etiological contributions to suicidal ideation, intention, and action were examined in order to characterize motives in these categories. METHODS Suicide attempters who visited the emergency departments of seven university hospitals were analyzed. Attempts leading to mortality were excluded from the analysis. Participants were assessed using semi-structured questionnaires, the results of which were noted on their medical records. These were analyzed retrospectively. RESULTS Attempter self-report assessment revealed that participants chose external sources of stress (75.4%) and psychiatric symptoms (19.1%) as their main reasons for attempting suicide. However, assessments by interviewers indicated that stressors contributed to suicide attempts to a lesser degree (52.8%) while psychiatric symptoms were more etiologically relevant (36.6%). Compared to those with stressors that was identified as causal in both self-report and clinician assessed evaluation, the participants-regardless of their self-report evaluation-who identified with causal psychiatric symptoms by psychiatrist had more severe and intense suicidal ideation and more determined suicidal intention. LIMITATIONS We collected samples from only university hospitals, resulting in selection bias. In addition, we did not use psychiatric scales to evaluate the participants׳ symptoms. CONCLUSIONS Stress was the greatest motive for attempting suicide, affirmed in both self-report and clinician assessed evaluation. A fair proportion of people were objectively identified as being motivated by psychiatric symptoms, yet were unaware of what they suffered from. Furthermore, suicide severity, intensity, and suicidal intention were stronger in psychiatrically driven cases.

Pattern of pharmacotherapy by episode types for patients with bipolar disorders and its concordance with treatment guidelines.

Abstract This study aimed to investigate the overall prescription pattern for patients with bipolar disorders in Korea and its relevance to the practice guidelines. Prescription records from all patients with bipolar I and II disorders who have been admitted or who started the outpatient treatment during the year of 2009 in 10 academic setting hospitals were reviewed. A total of 1447 patients with bipolar I and II disorders were included in this study. Longitudinal prescription patterns of inpatients and outpatients were analyzed by episode types and compared with the clinical practice guideline algorithms. In all phases, polypharmacy was chosen as an initial treatment strategy (>80%). The combination of mood stabilizer and atypical antipsychotics was the most favored. Antipsychotics were prescribed in more than 80% of subjects across all phases. The rate of antidepressant use ranged from 15% to 40%, and it was more frequently used in acute treatment and bipolar II subjects. The concordance rate of prescriptions for manic inpatients to the guidelines was higher and relatively more consistent (43.8%–48.7%) compared with that for depressive inpatients (18.6%–46.9%). Polypharmacy was the most common reason for nonconcordance. In Korean psychiatric academic setting, polypharmacy and atypical antipsychotics were prominently favored in the treatment of bipolar disorder, even with the lack of evidence of its superiority. More evidence is needed to establish suitable treatment strategies. In particular, the treatment strategy for acute bipolar depression awaits more consensuses.

Usefulness of the combined application of the Mood Disorder Questionnaire and Bipolar Spectrum Diagnostic Scale in screening for bipolar disorder

OBJECTIVE This study aimed to examine whether combined application of the Mood Disorder Questionnaire (MDQ) and Bipolar Spectrum Diagnostic Scale (BSDS) is more effective than exclusive application of either tool in screening for bipolar disorder (BD). METHOD The MDQ and BSDS were completed by a total of 113 patients diagnosed with BD and major depressive disorder who were experiencing a current major depressive episode. The initial diagnosis of the subject was confirmed during a 1-year follow-up period. When each MDQ and BSDS optimal cutoff score was calculated, a modified scoring method for the MDQ that considered only one item was used to increase its performance in this population. The following three combinations of the cutoff scores for the two tools were used to screen for BD: (A) The score on either the MDQ or BSDS was greater than or equal to the cutoff score; (B) the scores on both the MDQ and BSDS were greater than or equal to the cutoff score; and (C) Reducing either cutoff score by 1 point resulted in the MDQ and BSDS scores being greater than or equal to the cutoff score. The sensitivity, specificity, positive predictive value, and negative predictive value of the three methods, the MDQ, and the BSDS were compared for screening BD. RESULTS The sensitivity and specificity of the MDQ were 0.741 and 0.844, respectively, and those for the BSDS were 0.731 and 0.742, respectively. These indicators for the combined application of the MDQ and BSDS were as follows, respectively: method A 0.901 and 0.688, method B 0.580 and 0.875, and method C 0.691 and 0.844. Method A was superior to using one measure alone as well as to methods B and C with regard to sensitivity and negative predictive values. Method A also showed a higher sensitivity for BD subtypes than did the individual tools. Compared with the use of individual instruments, method A showed a similar positive predictive value. CONCLUSION This study suggests that combined use of the MDQ and BSDS is more effective than the individual use of either of these measures in screening for BD. The data also showed that when both tools were used, the most effective interpretation of the results in terms of screening for BD was achieved when positive scores were defined as those that were equal to or greater than the cutoff for the MDQ or BSDS.

Association between morningness and resilience in Korean college students

ABSTRACT Circadian typology and sleep quality may be essential factors associated with the promotion of resilience. However, previous studies investigating the association between circadian typology and resilience did not analyze the effects of sleep quality on resilience. Thus, the present study evaluated the association between circadian typology and resilience in Korean college students after controlling for sleep quality. Additionally, this study investigated several sleep-related variables, including sleep duration, social jetlag and sunlight exposure during the daytime, to examine the modifiable behavioral features of morningness and also investigated whether the findings regarding morningness-related modifiable habits were associated with resilience. This study included 1094 participants (947 males and 147 females) between 19 and 29 years of age (22.8 ± 1.9 years) who completed the 10-item Korean version of the Connor–Davidson Resilience Scale (CD-RISC-10), the Korean version of the Morningness–Eveningness Questionnaire (MEQ), the Pittsburgh Sleep Quality Index (PSQI), the Korean version of the Hospital Anxiety and Depression Scale (HADS) and a survey about social jetlag that determined misalignments between weekday and weekend times of awakening and activity duration under conditions of sunlight between 10:00 and 15:00. A multiple linear regression analysis revealed that sleep duration, mean daily sunlight exposure between 10:00 and 15:00 and age were positive predictors of morningness, whereas social jetlag was a negative predictor of morningness. Of these morningness-related modifiable behavioral features, mean daily sunlight exposure between 10:00 and 15:00 significantly predicted greater resilience. An additional multiple linear regression analysis revealed that morningness was a positive predictor of resilience after controlling for age, sex, depression, anxiety and sleep quality. These results support the idea that morningness and better sleep quality are associated with greater resilience. Morningness was also associated with longer sleep duration, longer sunlight exposure during the daytime and less social jetlag, whereas longer daily sunlight exposure between 10:00 and 15:00 was associated with greater resilience. Future longitudinal studies are needed to examine whether manipulations of morningness-related modifiable behavioral features can rearrange chronotype and promote resilience.

The effects of ethnic, social and cultural factors on axis I comorbidity of bipolar disorder: Results from the clinical setting in Korea

OBJECTIVE Ethnic, social and cultural factors contribute to axis I comorbid conditions in bipolar disorder (BPD). Korea has strict laws against illicit drugs and a relatively permissive prevailing attitude toward alcohol. The present study aimed to explore the lifetime axis I comorbidity rate in patients with BPD in Korea. METHODS Clinically stable patients with bipolar I (n=222) and bipolar II (n=194) disorders were recruited from four tertiary medical centers in Korea. The subjects׳ diagnoses and axis I comorbid conditions were evaluated using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID) and the Korean version of the Diagnostic Interview for Genetic Studies (K-DIGS). The lifetime prevalence of anxiety disorders, substance use disorders and eating disorders was explored. The prevalence of these axis I comorbid conditions was compared with data from prior studies in other countries and to data concerning the general Korean population. RESULTS A total of 45.1% of all subjects had at least one axis I comorbid condition. Anxiety disorders (30.2%) were the most common comorbidity, followed by alcohol use disorders (16.8%). Males with BPD showed a higher rate of alcohol dependence compared to the general male population and females with BPD showed a greater risk of having alcohol use disorder compared to the general female population. The rate of drug use disorder was extremely low (1.7%), and only one subject had an illicit-drug-related problem. LIMITATION Cross-sectional studies. CONCLUSION Comorbid conditions of Korean patients with BPD showed a distinct pattern, which is associated with the ethnic, social and cultural characteristics in Korea.

The Relationship between Impulsivity and Quality of Life in Euthymic Patients with Bipolar Disorder

Objective Bipolar disorder (BD) is characterized by elevated impulsivity, even during periods of remission. Many recovered BD patients have functional impairments, which can lead to poor quality of life (QoL). The aim of this study was to investigate the association between impulsivity and QoL in euthymic BD patients. Methods A total of 56 remitted or recovered patients with type I or II BD, diagnosed based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria, were recruited. Psychiatrists administered the Clinical Global Impression (CGI) for BD and the Global Assessment of Functioning (GAF) scales and then interviewed the subjects to assess clinical variables. Patients completed the Barratt Impulsiveness Scale (BIS-11) and the World Health Organization Quality of Life Assessment Instrument-Brief Form (WHOQoL-BREF). Pearson correlations, univariate regression analyses, and multiple linear regression analyses were performed. Results The BIS-11 total score was significantly correlated with the WHOQoL-BREF total score (r=-0.55, p<0.01) and with the WHOQoL-BREF subscales. After controlling for GAF score and other clinical variables, the BIS-11 total score (β=-0.43, p=0.001) was independently associated with overall QoL. Additionally, the BIS-11 total score was particularly strongly associated with the physical, psychological, and social domains of the multi-dimensional QoL scale. Conclusion Our results suggest that high impulsivity is related to low QoL in euthymic BD patients. Further studies are needed to examine whether interventions for high impulsivity effectively improve QoL in patients with BD.

Neuregulin 3 does not confer risk for schizophrenia and smooth pursuit eye movement abnormality in a Korean population

Located on chromosome 10q22‐q23, the human neuregulin3 (NRG3) is considered to be a strong positional and functional candidate gene for schizophrenia pathogenesis. Several case–control studies examining the association of polymorphisms in NRG3 with schizophrenia and/or related traits such as delusion have been reported recently in cohorts of Han Chinese, Ashkenazi Jews, Australians and white Americans of Western European ancestry. Thus, this study aimed to comprehensively investigate the association of NRG3 genetic variations with the risk of schizophrenia and smooth pursuit eye movement (SPEM) abnormality in a Korean population. Using TaqMan assay, six single‐nucleotide polymorphisms (SNPs) in the intronic region of NRG3 were genotyped and two major haplotypes were identified in 435 patients with schizophrenia as cases and 393 unrelated healthy individuals as controls. A total of 113 schizophrenia patients underwent an eye tracking task, and degree of SPEM abnormality was measured using the logarithmic values of the signal/noise (Ln S/N) ratio. Differences in frequency distributions were analyzed using logistic and regression models following various modes of genetic inheritance and controlling for age and sex as covariates. Subsequent analysis revealed that the frequency distributions of NRG3 polymorphisms and haplotypes were similar between schizophrenia patients and healthy controls of Korean ethnicity. Furthermore, no significant differences were observed between the genetic variants tested for SPEM abnormality. By elucidating a lack of association in a Korean population, findings from this study may contribute to the understanding of the genetic etiology focusing on the role of NRG3 in schizophrenia pathogenesis.

Characteristics of methods of suicide attempts in Korea: Korea National Suicide Survey (KNSS).

BACKGROUND Because the method used for a suicide attempt is an important determinant of outcome, these methods should be explored. The present study was a nationwide investigation of suicide attempts and the characteristics of suicidal behavior. AIMS To compare the suicide methods used in attempted suicides with those used in completed suicides and to examine the factors associated with each phenomenon. METHODS The present study reviewed the medical charts of subjects who had attempted suicide and subsequently visited the emergency rooms of 17 medical centers from May 1, 2013 to November 7, 2013. All subjects completed a full psychiatric interview conducted by trained psychiatric residents. Suicide-attempt methods were divided into the following six categories: drug poisoning, pesticide poisoning, gassing, cutting, hanging, and others. The associations among demographic variables, related psychiatric variables, and suicide-attempt methods were analyzed using a multinomial regression analysis. RESULTS Of the 1359 suicide attempts or instrumental suicide-related behaviors with/without injuries and the 14,160 completed suicides, drug poisoning and cutting were the most common suicidal behaviors with/without injuries, but they were the least frequent method of completed suicides. In contrast, hanging and jumping from a height were less common among failed suicide attempts but resulted in a higher percentage of fatalities. Being male, age, and area of residence were associated with pesticide poisoning, whereas previous suicide attempts were associated with cutting, pesticide poisoning, and gassing. CONCLUSION A previous suicide attempt is a risk factor for suicide; thus, assessing the characteristics of suicide attempts or instrumental suicide-related behaviors with/without injuries is necessary to prevent these attempts. The present findings showed that the methods of suicide used by individuals who only attempted suicide differed from those used by individuals who completed. Of the suicide methods, pesticide poisoning was related to age, residential area (urban), and a history of previous suicide attempts.