Eunsoo Moon

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.

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.

Delay in the Recovery of Normal Sleep-Wake Cycle after Disruption of the Light-Dark Cycle in Mice: A Bipolar Disorder-Prone Animal Model?

Objective Disruption of the circadian rhythm is known as a provoking factor for manic episodes. Individual differences exist in the recovery rate from disruption in the general population. To develop a screening method to detect individuals vulnerable to bipolar disorder, the authors observed the relationship between the recovery of the normal sleep-wake cycle after switching the light-dark (LD) cycle and quinpirole-induced hyperactivity in mice. Methods Sixteen male mice (age of 5 weeks, weight 28-29 gm) were subjected to a circadian rhythm disruption protocol. Sleep-wake behaviors were checked every 5 min for a total duration of 15 days, i.e., 2 days of baseline observations, 3 days of LD cycle changes, and 10 days of recovery. During the dark cycle on the 16th experimental day, their general locomotor activities were measured in an open field for 120 minutes after an injection of quinpirole (0.5 mg/kg, s.c.). Results The individual differences in the recovery rate of the baseline sleep-wake cycle were noted after 3 days of switching the LD cycle. Fifty percent (n=8) of the mice returned to the baseline cycle within 6 days after normalizing the LD cycle (early recovery group). The locomotor activities of mice that failed to recover within 6 days (delayed recovery group) were significantly higher (mean rank=12.25) than those of the early recovery group (mean rank=4.75, u=62.0, p=0.001, Mann-Whitney U test). Conclusion Given that the quinpirole-induced hyperactivity is an animal model of bipolar disorder, our results suggest individuals who have difficulties in recovery from circadian rhythm disruption may be vulnerable to bipolar disorder.

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.

A Combination of the Korean Version of the Mini-Mental State Examination and Korean Dementia Screening Questionnaire Is a Good Screening Tool for Dementia in the Elderly

Objective The aim of this study is to investigate whether a combination of the Korean version of the mini-mental state examination (K-MMSE) and the Korean dementia screening questionnaire (KDSQ) is better than the use of test alone when differentiating patients with dementia from those without dementia in Korea. Methods The subjects (patients without dementia, 1120; patients with dementia, 908) were recruited from the Clinical Research Center for Dementia of South Korea. K-MMSE and KDSQ were used. Diagnosis of dementia was made according to the Diagnostic and Statistical Manual of Mental Disorders, fourth Edition. The weighted sum rule derived from logistic regression analysis was used for the combination of K-MMSE and KDSQ. Results On comparing the Area Under the Curve for each test using the method of Hanley and McNeil, the weighted sum was significantly greater than KDSQ or K-MMSE, and K-MMSE was significantly greater than KDSQ. Conclusion This study shows that when differentiating patients with dementia from those without dementia in Korea, a combination of K-MMSE and KDSQ achieved using the weighted sum method is better than either test performed alone. Further epidemiological studies in community-based settings are required before our results can be generalized to nonclinical samples.

Anal Human Papillomavirus Infection among HIV-Infected Men in Korea

Background Little is known about the epidemiology on human papillomavirus (HPV) infection among HIV-infected men in Korea. The objective of this study was to determine the prevalence, genotype distribution and risk factors associated with anal HPV infection among HIV-infected men in Korea. Methods A single-center cross-sectional study was conducted with HIV-infected men in Korea. Participants completed a detailed sexual behavior risk factor questionnaire. Anal samples were collected for cytology and HPV genotyping. Factors associated with anal HPV infection were assessed using multivariable logistic regression, stratifying by sexual behaviour. Results A total of 201 HIV-infected men were included in the study: 133 were from men who have sex with men (MSM) and 68 from men who have sex with women (MSW). Any anal HPV infection was detected in 82.7% of HIV-infected MSM and in 51.5% of HIV- infected MSW (P < 0.001). High-risk HPV (HR-HPV) prevalence was higher among MSM (47.4%) than MSW (25.0%; P = 0.002). The HR-HPV types identified most frequently were HPV 16 (11%), HPV 18 (9.9%), and HPV 58 (5%) in MSM, and HPV 58(11%) and HPV 16 (8.9%) in MSW. Prevalence of any HPV types in 9-valent vaccine types was higher among MSM than MSW (47.4% vs 22.1%. P = 0.001). Abnormal anal cytology was more commonly detected in MSM than MSW (42.9% vs.19.1%, P < 0.001). In HIV-infected MSM, higher number of lifetime male sex partners was significantly associated with any anal HPV infection, but age was a significant risk factor associated with anal HR-HPV infection. Conclusion Anal HPV infection was highly prevalent in HIV-infected MSM in Korea, and also commonly found in HIV-infected MSW. In HIV-infected MSM, the significant risk factor for being infected with any HPV infection was lifetime number of male sexual partners, and with anal oncogenic HPV infection was age.

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.

Impact of Apolipoprotein E4 Polymorphism on the Gray Matter Volume and the White Matter Integrity in Subjective Memory Impairment without White Matter Hyperintensities: Voxel‐Based Morphometry and Tract‐Based Spatial Statistics Study under 3‐Tesla MRI

The aim of this study is to compare gray matter (GM) volume and white matter (WM) integrity in Apolipoprotein E4 (ApoE ε4) carriers with that of ApoE ε4 noncarriers using the voxel‐based morphometry and diffusion tensor imaging (DTI) to investigate the effect of the ApoE ε4 on brain structures in subjective memory impairment (SMI) without white matter hyperintensities (WMH).