Identifying predictive factors for mood recurrence in early-onset major mood disorders: A 4-year, multicenter, prospective cohort study

We investigate the predictive factors of the mood recurrence in patients with early-onset major mood disorders from a prospective observational cohort study from July 2015 to December 2019. A total of 495 patients were classified into three groups according to recurrence during the cohort observation period: recurrence group with (hypo)manic or mixed features (MMR), recurrence group with only depressive features (ODR), and no recurrence group (NR). As a result, the baseline diagnosis of bipolar disorder type 1 (BDI) and bipolar disorder type 2 (BDII), along with a familial history of BD, are strong predictors of the MMR. The discrepancies in wake-up times between weekdays and weekends, along with disrupted circadian rhythms, are identified as a notable predictor of ODR. Our findings confirm that we need to be aware of different predictors for each form of mood recurrences in patients with early-onset mood disorders. In clinical practice, we expect that information obtained from the initial assessment of patients with mood disorders, such as mood disorder type, family history of BD, regularity of wake-up time, and disruption of circadian rhythms, can help predict the risk of recurrence for each patient, allowing for early detection and timely intervention.

Dietary Carotene Intake and Suicidal Ideation in Korean Females: Analysis of Data From the Korea National Health and Nutrition Examination Survey (2012, 2013, and 2015)

OBJECTIVE

The suicide rate in Korea was the highest among countries in the Organisation for Economic Co-operation and Development in 2019. In a previous study, higher intake of vegetables and fruits was associated with a lower risk of suicidal ideation, and carotene-rich fruits and vegetables lowered the risk of depression. This study aimed to examine the direct relationship between carotene intake and suicidal ideation, adjusting for the effect on depression.

METHODS

This study used data from the Korea National Health and Nutrition Examination Survey (KNHANES) conducted in 2012, 2013, and 2015. Carotene intake was assessed through a food intake frequency survey with a 24-hour recall. Suicidal ideation and depression were assessed using the mental health section of the KNHANES. We applied logistic regression to assess the relationship between carotene intake and suicidal ideation, adjusting for potential confounders.

RESULTS

A total of 5,480 females aged 19-64 years were included in this study. Carotene intake was significantly lower in the suicidal ideation group (3,034.5±1,756.4 μg/day) than in the nonsuicidal ideation group (3,225.4±1,795.1 μg/day) (p=0.015). We found a significant inverse association between carotene intake and the risk of suicidal ideation after adjusting for potential confounders (odds ratio=0.934, 95% confidence interval=0.873-0.999).

CONCLUSION

These results suggest that carotene intake may be inversely associated with the risk of suicidal ideation. Our findings may inform the development of new nutritional interventions to prevent increases in the risk of suicide worldwide.

Association Between Depressed Mood Changes and Physical Activity Among Adolescents Post COVID-19 Pandemic

Objectives

Following the coronavirus disease 2019 (COVID-19) pandemic, adolescents have experienced decreased physical activity and a decline in mental health. This study analyzed the association between changes in depressed mood after the COVID-19 pandemic and physical activity among adolescents.

Methods

The analysis was based on the results of the 17th Youth Health Behavior Online Survey conducted in 2021, which included 54848 middle and high school students in South Korea. Information on physical activity included low-intensity physical activity lasting >60 min/day, high-intensity physical activity, and strength training exercises. A logistic regression analysis was performed to evaluate the association between physical activity and changes in depression after the COVID-19 pandemic.

Results

After adjusting for sociodemographic characteristics and previous depression, adolescents who performed strength training exercises more than once per week had a 0.95-fold lower risk (odds ratio [OR]=0.948, 95% confidence interval [CI]=0.905-0.994, p= 0.027) of increasing depression after the COVID-19 pandemic, while the risk of decreasing depression increased by 1.22-fold (OR=1.215, 95% CI=1.131-1.305, p<0.001). The results were not significant for low-intensity physical activity for >60 min/day and high-intensity physical activity.

Conclusion

Strength-training exercises are significantly associated with the prevention of depression among adolescents following the COVID-19 pandemic.

Prediction of impending mood episode recurrence using real-time digital phenotypes in major depression and bipolar disorders in South Korea: a prospective nationwide cohort study

BACKGROUND

Mood disorders require consistent management of symptoms to prevent recurrences of mood episodes. Circadian rhythm (CR) disruption is a key symptom of mood disorders to be proactively managed to prevent mood episode recurrences. This study aims to predict impending mood episodes recurrences using digital phenotypes related to CR obtained from wearable devices and smartphones.

METHODS

The study is a multicenter, nationwide, prospective, observational study with major depressive disorder, bipolar disorder I, and bipolar II disorder. A total of 495 patients were recruited from eight hospitals in South Korea. Patients were followed up for an average of 279.7 days (a total sample of 75 506 days) with wearable devices and smartphones and with clinical interviews conducted every 3 months. Algorithms predicting impending mood episodes were developed with machine learning. Algorithm-predicted mood episodes were then compared to those identified through face-to-face clinical interviews incorporating ecological momentary assessments of daily mood and energy.

RESULTS

Two hundred seventy mood episodes recurred in 135 subjects during the follow-up period. The prediction accuracies for impending major depressive episodes, manic episodes, and hypomanic episodes for the next 3 days were 90.1, 92.6, and 93.0%, with the area under the curve values of 0.937, 0.957, and 0.963, respectively.

CONCLUSIONS

We predicted the onset of mood episode recurrences exclusively using digital phenotypes. Specifically, phenotypes indicating CR misalignment contributed the most to the prediction of episodes recurrences. Our findings suggest that monitoring of CR using digital devices can be useful in preventing and treating mood disorders.

Spatiotemporal Patterns of Suicide in Korea From 2009 to 2019 Using Geographic Information Systems

Objective

When analyzing factors related to suicide, it is necessary to consider the regional characteristics of the areas where individuals live in addition to individual factors. This study aimed to investigate the spatiotemporal association between suicide rates and geographic features and the patterns of this association for all administrative areas in South Korea from 2009 to 2019.

Methods

The data used in this study were obtained from the National Statistical Office of the Korean Statistical Information Service. For suicide rates, age-standardized mortality index data per 100 000 people were used. All administrative districts from 2009 to 2019 were divided into 229 regions. Emerging hotspot analysis was used for a 3-dimensional analysis to simultaneously evaluate temporal and spatial clusters.

Results

In the 229 regions, there were 27 (11.8%) hotspots and 60 (26.2%) cold spots. Hotspot pattern analysis found 2 (0.9%) new spots, 1 (0.4%) persistent spot, 23 (10.0%) sporadic spots, and 1 (0.4%) oscillating spot.

Conclusion

This study found geographic differences in the spatiotemporal patterns of suicide rates in South Korea. The utilization of national resources for suicide prevention should be selectively and intensively prioritized in 3 areas that exhibit unique spatiotemporal patterns.

The relationship between morningness-eveningness and mood symptoms and quality of life in euthymic state of mood disorders: Results from a prospective observational cohort study

BACKGROUND

The clinical importance of morningness-eveningness, especially in mood disorders, is prevailing. The differential relation of chronotype with diagnoses of early-onset mood disorders, mood symptoms, anxiety, and quality of life was evaluated.

METHODS

Early-onset mood disorder patients [n = 419; 146 major depressive disorder (MDD); 123 bipolar I disorder (BDI); 150 bipolar II disorder (BDII)] from the Mood Disorder Cohort Research Consortium were assessed for chronotype using the composite scale for morningness (CSM) and its association with clinical variables obtained during the clinician-verified euthymic state.

RESULTS

The mean total CSM of BDI was significantly higher than MDD and BDII (p < 0.001). In all types of mood disorders, higher total CSM was associated with lower Quick inventory of depressive symptomatology (p < 0.005) and higher WHO quality of life (p < 0.005). Such negative correlations between the total CSM and Montgomery-Asberg depression rating were significant in MDD and BDI (p < 0.05) and marginally significant in BDII (p = 0.077). CSM was a significant contributor to quality of life in BDI (p < 0.001) and BDII (p = 0.011), but it was not for MDD.

LIMITATIONS

The defined 'euthymic state' that may not fully reflect the remission of episode; limited generalizability due to clinical characteristic of early-onset mood disorder; the disparity between diurnal preference measured by the CSM and chronotype; possible effects of the last mood episode polarity and medication; and, lack of control group.

CONCLUSION

Less eveningness was associated with less severe depressive symptoms and better quality of life. This suggests that morningness may reduce residual depressive symptoms and recover function of patients.

Association Between Suicide and Drinking Habits in Adolescents

Objectives

Adolescent suicide is a serious social problem. Adolescent alcohol use is one of the most important risk factors for adolescent suicide. This study aimed to identify the relationship between drinking habits and suicide among Korean adolescents.

Methods

Data from the 14th and 15th Korean Youth Risk Behavior Web-based Survey, conducted in 2018 and 2019, were used for analysis. Multiple logistic regression analysis was used to identify the relationship between drinking habits—including the age of drinking initiation, frequency of drinking, average drinking amount, frequency of drunkenness—and suicidal ideation, plans, and attempts.

Results

Even after adjusting for age, sex, school grade, academic achievement, socioeconomic status, depression, stress, and drinking habits, the frequencies of drinking and drunkenness increased the risk of suicide attempts. Suicide attempts were associated with the frequency of drinking in girls and middle school students, and with the frequency of drunkenness in boys and high school students.

Conclusion

This study identified associations between drinking habits (the age of drinking initiation, frequency of drinking, average amount of drinking, frequency of drunkenness) and suicidal behavior in adolescents. Our findings suggest that to prevent adolescent suicide, it might be necessary to investigate drinking habits, including the frequencies of drinking and drunkenness. Moreover, considering the differences in sex and school grade, it is important to include the individual group characteristics when evaluating drinking habits.

Bipolar II disorder has the highest prevalence of seasonal affective disorder in early-onset mood disorders: Results from a prospective observational cohort study

BACKGROUND

Many mood disorder patients experience seasonal changes in varying degrees. Studies on seasonality have shown that bipolar disorder has a higher prevalence rate in such patients; however, there is limited research on seasonality in early-onset mood disorder patients. This study estimated the prevalence of seasonality in early-onset mood disorder patients, and examined the association between seasonality and mood disorders.

METHODS

Early-onset mood disorder patients (n = 378; 138 major depressive disorder; 101 bipolar I disorder; 139 bipolar II disorder) of the Mood Disorder Cohort Research Consortium and healthy control subjects (n = 235) were assessed for seasonality with Seasonality Pattern Assessment Questionnaire (SPAQ).

RESULTS

A higher global seasonality score, an overall seasonal impairment score, and the prevalence of seasonal affective disorder (SAD) and subsyndromal SAD showed that mood disorder subjects had higher seasonality than the healthy subjects. The former subject group had a significantly higher mean overall seasonal impairment score than the healthy subjects (p < .001); in particular, bipolar II disorder subjects had the highest prevalence of SAD, and the diagnosis of bipolar II disorder had significantly higher odds ratios for SAD when compared to major depression and bipolar I disorder (p < .05).

CONCLUSIONS

Early-onset mood disorders, especially bipolar II disorder, were associated with high seasonality. A thorough assessment of seasonality in early-onset mood disorders may be warranted for more personalized treatment and proactive prevention of mood episodes.

Association between Early Spermarche and Suicide Attempts in Boys: the Korea Youth Risk Behavior Web-based Survey

BACKGROUND

Puberty is a biologically and psychologically unstable period, and pubertal changes differ by sex. However, most previous studies on pubertal timing and suicide have focused on girls. This study investigated the association between early spermarche and suicide attempts in boys.

METHODS

We analyzed a nationally representative sample of Korean adolescents (The Korea Youth Risk Behavior Web-Based Survey, KYRBS) that included approximately 35,000 boys annually from 2011 to 2015. Pubertal timing in boys was defined by spermarche. Complex sampling logistic regression analyses were performed to evaluate the odds ratios (ORs) for suicide attempts between the early and average spermarche groups.

RESULTS

The ORs for suicide attempts in boys with early spermarche were significantly higher than those in boys with average spermarche after adjustment for age, perceived stress, depressive symptoms, and suicidal ideation. The ORs from 2011 to 2015 were as follows: 1.782 (P < 0.001), 1.490 (P = 0.002), 1.693 (P < 0.001), 1.541 (P = 0.001), and 1.393 (1.024-1.895; P = 0.035), respectively.

CONCLUSION

These findings suggest that early pubertal timing is a risk factor for suicide attempts in Korean boys after adjustment for depressive symptoms, perceived stress, and suicidal ideation, which have been previously reported as risk factors for suicide attempts. Therefore, careful attention should be paid to the prevention of suicide in boys who experience early spermarche in Korea.

Psychological Development during Medical School Clerkship: Relationship to Resilience

OBJECTIVE

The authors investigated changes in medical students' defenses during clerkship and examined the effects of these changes on students' resilience.

METHODS

Between 2012 and 2014, all year-2 preclinical students (N = 249) at Gyeongsang National University Medical School were asked to participate. Those who agreed to participate (N = 237) completed the Korean version of the Defense Style Questionnaire (K-DSQ) and the Connor-Davidson resilience scale-10 (CD-RISC-10). After clerkship, students who proceeded to year 4 in 2 years (n = 187 (93 females), aged 24-38 years (mean, 28.9 ± 2.8 years)) completed the K-DSQ, CD-RISC-10, and the Korean version of the Hospital Anxiety and Depression Scale (K-HADS) in September 2014, 2015, and 2016.

RESULTS

The use of adaptive (W = 11,603.5, p < 0.001, r = 0.39) and self-inhibiting (W = 10,901.5, p < 0.001, r = 0.32) styles increased significantly after clerkship. A multiple linear regression analysis showed that changes in adaptive defense styles (B = 1.336, SE = 0.386, β = 0.218, p = 0.001) during clerkship were significantly related to resilience after adjusting for age, sex, depression, and anxiety.

CONCLUSIONS

Both positive personality development and maladaptive changes in defenses were evident. An increase in the adaptive defense style score was related to resilience.

Similarities of Aspects of Biological Rhythms between Major Depression and Bipolar II Disorder Compared to Bipolar I Disorder: A Finding from the Early-Onset Mood Disorder Cohort

OBJECTIVE

The biological rhythm is closely related to mood symptoms. The purpose of this study was to assess the differences in biological rhythms among subjects with mood disorder [bipolar I disorder (BD I), bipolar II disorder (BD II), major depressive disorder (MDD)] and healthy control subjects.

METHODS

A total of 462 early-onset mood disorder subjects were recruited from nine hospitals. The controls subjects were recruited from the general population of South Korea. Subject groups and control subject were evaluated for the Korean language version of Biological Rhythms Interview of Assessment in Neuropsychiatry (K-BRIAN) at the initial evaluation.

RESULTS

The mean K-BRIAN scores were 35.59 [standard deviation (SD)=13.37] for BD I, 43.05 (SD=11.85) for BD II, 43.55 (SD=12.22) for MDD, and 29.1 (SD=8.15) for the control group. In the case of mood disorders, biological rhythm disturbances were greater than that in the control group (p<0.05). A significant difference existed between BD I and BD II (BD I <BD II, p<0.001) and between BD I and MDD (BD I<MDD, p< 0.001) but no difference was observed between BD II and MDD.

CONCLUSION

BD II and MDD are similar to each other but different from BD I in biological rhythm patterns in early-onset mood disorder cases. Biological rhythm disturbances are similar for early-onset major depression and BD II.

The Mediating Effect of Impulsivity on Resilience and Depressive Symptoms In Korean Conscripts

OBJECTIVE

Resilience and impulsivity have opposite effects on depression in stressful situations. This study aimed to investigate the association among resilience, impulsivity, and depression in young males.

METHODS

The participants consisted of 429 conscripts who underwent military training over 5 weeks. The surveys included the Connors- Davidson Resilience Scale-Korean version, the Barratt Impulsiveness Scale-11-Revised, and the Center for Epidemiological Studies- Depression Scale. The surveys were administered both before and after training.

RESULTS

When simultaneously considering impulsivity and resilience, resilience was not associated with depression. Impulsivity had a complete negative mediating effect on resilience and depressive symptoms. Impulsivity is a significant negative mediating factor for the protective effect of resilience on depression.

CONCLUSION

This study recommends considering impulsivity when evaluating the protective role of resilience against depression.

Effects of Emotional Stability on Insomnia through Anxiety in Patients with Cataracts

This study investigated the effect of emotional stability (ES) on insomnia through anxiety in preoperative patients with cataracts. Fifty-four subjects completed a self-questionnaire that included the Insomnia Severity Index (ISI), the International Personality Item Pool (IPIP) for ES, and the Hospital Anxiety and Depression scale (HADS). Pathway analysis was performed to analyze the mediating effects of ES, the anxiety subscale scores of the HADS, and the ISI scores. The low-ES group exhibited an insomnia severity that was significantly higher than that of the high-ES group (p=0.048). According to the pathway analysis, the significant indirect effect of ES on the ISI scores was mediated by the scores on the anxiety subscale of the HADS. Cataract patients with low ES waiting to undergo surgery have a high risk of experiencing insomnia due to anxiety. Before surgery, it is essential to identify patients' personality characteristics and provide appropriate intervention.

More Resilience in Males with Probable Bipolar Depression than Probable Unipolar Depression among Korean Conscripts

OBJECTIVE

This study investigated whether the resilience of males with probable bipolar depression (PBD) can be strengthened and compared it to that of males with probable unipolar depression (PUD).

METHODS

Prospective data for 198 participants (PBD: 66, PUD: 66, normal control: 66) were analyzed. The participants' resilience, bipolarity and severity of depressive symptoms were evaluated at baseline and after 5 weeks. Analysis of variance (ANOVA) and repeated measure ANOVA was performed for comparing resilience between three groups through a basic military training.

RESULTS

The PBD group demonstrated more resilience than the PUD group at baseline. Participants with PBD became significantly more resilient than participants with PUD after 5 weeks (p<0.01, F=6.967, η²_p=0.052).

CONCLUSION

The study indicates that interventions that strengthen resilience need to be developed for males with PBD and that such interventions are more effective for males with PBD than PUD.

Effects of resilience on quality of life in patients with bipolar disorder

BACKGROUND

Few studies have examined the effects of resilience on quality of life (QOL) in patients with bipolar disorder (BD). Therefore, this study investigated the association between resilience and QOL in patients with BD and compared it to the relationship between resilience and QOL in healthy individuals.

METHODS

Participants were 68 euthymic patients with BD and 68 age-, sex-, and length of education-matched controls. Sociodemographic characteristics and clinical variables of the two groups were obtained using face-to-face interviews, and all participants completed the Connor-Davidson Resilience Scale, the World Health Organization QOL-Brief Form.

RESULTS

The QOL of the BD group was significantly impaired compared with that of the controls. Degree of resilience, number of depressive episodes, Clinical Global Impression scores, degree of impulsivity, and length of education were significantly correlated with QOL in the BD group. Resilience was significantly associated with overall QOL, physical subdomains of QOL, psychological subdomains of QOL, social subdomains of QOL, and environmental subdomains of QOL in the BD group, even after controlling for confounders. In the control group, resilience was significantly associated with overall QOL, the physical subdomains of QOL, psychological subdomains of QOL, and social subdomains of QOL.

LIMITATIONS

The number of participants in each group was 68, which is a relatively small sample size.

CONCLUSIONS

Resilience in patients with BD was independently and positively correlated with various areas of QOL. Various strategies to reinforce resilience in patients with BD are needed to improve the low QOL in this population.

Design and Methods of the Mood Disorder Cohort Research Consortium (MDCRC) Study

The Mood Disorder Cohort Research Consortium (MDCRC) study is designed as a naturalistic observational prospective cohort study for early-onset mood disorders (major depressive disorders, bipolar disorders type 1 and 2) in South Korea. The study subjects consist of two populations: 1) patients with mood disorders under 25 years old and 2) patients with mood disorders within 2 years of treatment under 35 years old. After successful screening, the subjects are evaluated using baseline assessments and serial follow-up assessments at 3-month intervals. Between the follow-up assessments, subjects are dictated to check their own daily mood status before bedtime using the eMood chart application or a paper mood diary. At the regular visits every 3 months, inter-visit assessments are evaluated based on daily mood charts and interviews with patients. In addition to the daily mood chart, sleep quality, inter-visit major and minor mood episodes, stressful life events, and medical usage pattern with medical expenses are also assessed. Genomic DNA from blood is obtained for genomic analyses. From the MDCRC study, the clinical course, prognosis, and related factors of early-onset mood disorders can be clarified. The MDCRC is also able to facilitate translational research for mood disorders and provide a resource for the convergence study of mood disorders.

Review of Cohort Studies for Mood Disorders

This paper aimed to review currently available cohort studies of subjects with mood disorders such as major depressive disorder (MDD) and bipolar disorder (BD). Using the PubMed and KoreaMed databases, we reviewed eight major cohort studies. Most studies recruited participants with MDD and BD separately, so direct comparison of factors associated with diagnostic changes was difficult. Regular and frequent follow-up evaluations utilizing objective mood ratings and standardized evaluation methods in a naturalistic fashion are necessary to determine detailed clinical courses of mood disorders. Further, biological samples should also be collected to incorporate clinical findings in the development of new diagnostic and therapeutic approaches. An innovative cohort study that can serve as a platform for translational research for treatment and prevention of mood disorders is critical in determining clinical, psychosocial, neurobiological and genetic factors associated with long-term courses and consequences of mood disorders in Korean patients.

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.

Allergic diseases, excessive Internet use and suicidal ideation in Korean adolescents

OBJECTIVE

The aim of this study is to evaluate the relation between suicidal ideation, allergic diseases, and excessive Internet use in Korean youth using a national representative dataset.

METHODS

Data from the Korean Youth Risk Behavior Web-Based Survey (KYRBWS), conducted by the Korean Centers for Disease Control and Prevention, were used in this study. Complex sample logistic regression and structural equation modeling were performed to define the relation between suicidal ideation, allergic disease and excessive Internet use.

RESULTS

A total of 73,238 students participated in this survey. In Korea, 19.3% of adolescents had suicidal ideation in the previous year. Asthma (OR=1.23, 95% CI=1.15-1.32, p<0.01) and allergic rhinitis (OR=1.17, 95% CI=1.11-1.22, p<0.01) were identified as risk factors for suicidal ideation after adjusting for school and family factors. Structural equation modeling showed that excessive Internet use interacted with the association between allergic diseases and suicidal ideation.

CONCLUSION

Allergy problems could positively affect suicidal ideation in Korean adolescents. Excessive Internet use could be a mediating factor between allergic disease and suicidal ideation.

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.

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.

Characteristics of stress-coping behaviors in patients with bipolar disorders

Appropriate stress-coping strategies are needed to improve the outcome in the treatment of bipolar disorders, as stressful life events may aggravate the course of the illness. The aim of this study was to compare stress-coping behaviors between bipolar patients and healthy controls. A total of 206 participants comprising 103 bipolar patients fulfilling the Diagnostic and Statistical Manual for Axis I disorder fourth edition (DSM-IV) diagnostic criteria for bipolar I and II disorders and controls matched by age and sex were included in this study. Stress-coping behaviors were assessed using a 53-item survey on a newly-designed behavioral checklist. The characteristics of stress-coping behaviors between the two groups were compared by using t-test and factor analysis. Social stress-coping behaviors such as 'journey', 'socializing with friends', and 'talking something over' were significantly less frequent in bipolar patients than controls. On the other hand, pleasurable-seeking behaviors such as 'smoking', 'masturbation', and 'stealing' were significantly more frequent in bipolar patients than controls. These results suggest that bipolar patients may have more maladaptive stress-coping strategies than normal controls. It is recommended to develop and apply psychosocial programs to reduce maladaptive stress-coping behaviors of bipolar patients.

Metabolic syndrome and suicidal ideation in korean based on the 2010 korean national health and nutrition examination survey

The aim of this study was to investigate the relationship between metabolic syndrome and suicidal ideation in Korean. This study was based on the 2010 Korean National Health and Nutrition Examination Survey. A questionnaire was used to measure suicidal ideation and physical examination was performed to measure waist circumference, blood pressure, fasting glucose, cholesterol and triglyceride levels. Complex samples logistic regression was performed to estimate the relationship between metabolic syndrome and suicidal ideation among adults and adolescents. Subjects with metabolic syndrome were more likely to have suicidal ideation in adult. There would be essential needs to evaluate suicidal ideation in adult with metabolic syndrome and to follow up suicidal ideation in adolescents with metabolic syndrome.

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.

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.

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.

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.

15-deoxy-D12,14-prostaglandin J2 suppresses RANTES expression by inhibiting NADPH oxidase activation in Helicobacter pylori-infected gastric epithelial cells

Peroxisome proliferators-activated receptor-γ (PPAR-γ) is a ligand-activated transcription factor. 15 deoxy-(12,14) prostaglandin J(2) (15d-PGJ(2)) is a potent PPAR-γ ligand and acts as an anti-inflammatory agent via PPAR-γ-dependent and independent mechanisms. Helicobacter pylori (H. pylori) induces gastric inflammation by inducing the activation of oxidant-sensitive transcription factor NF-κB and cytokine expression in gastric epithelial cells. Since 15d-PGJ(2) inhibits NF-κB activation in various cells, it may suppress H. pylori-induced inflammatory signaling and cytokine expression in gastric epithelial cells. The present study aims to determined the effect of 15d-PGJ(2) on the activation of inflammatory mediators Jak/Stat (Janus kinase/signal transducers and activators of transcription) and induction of cytokine RANTES in H. pylori-infected gastric epithelial AGS cells. Since NADPH oxidase is a candidate for the production of reactive oxygen species in H. pylori-infected gastric epithelial cells, we determined the effect of 15d-PGJ(2) on the activation of NADPH oxdase. AGS cells were cultured in the presence of H. pylori treated with or without 15d-PGJ(2). The activations of NADPH oxidase and Jak1/Stat3, the levels of H(2)O(2) and RANTES in the medium, and DNA binding activity of Stat3 were assessed. A Jak/Stat3 specific inhibitor AG490 and an inhibitor of NADPH oxidase diphenyleneiodonium (DPI) were treated to determine the direct involvement of Jak/Stat and NADPH oxidase on the production of H(2)O(2) and RANTES in H. pylori-infected cells. H. pylori induced the production of H(2)O(2) and RANTES as well as the activations of NADPH oxidase and Jak1/Stat3, which were inhibited by the treatment of 15d-PGJ(2). DPI suppressed H. pylori-induced alterations similar to 15d-PGJ(2). However, AG490 had no effect on NADPH oxidase activation, but reduced the level of RANTES in the medium released from H. pylori-infected cells.

CONCLUSION

NADPH oxidase activation is an upstream signaling of Jak1/Stat3 activation and induction of RANTES in H. pylori-infected AGS cells. 15d-PGJ(2), inhibits the activations of NADPH oxidase and Jak1/Stat3 and RANTES expression, suggesting that 15d-PGJ(2) may be beneficial for the treatment of H. pylori-induced gastric inflammation.

Polarity of the first episode and time to diagnosis of bipolar I disorder

OBJECTIVE

The current study explored the relationship between the polarity of the first episode and the timing of eventual diagnosis of bipolar I disorder, and associated clinical implications.

METHODS

Twelve years of clinical data from the medical records of 258 inpatients meeting DSM-III-R or DSM-IV criteria for bipolar I disorder were analyzed. Subjects were divided into two groups according to the polarity of the first episode: those with depressive polarity (FE-D), and those with manic polarity (FE-M). Comparisons were made between the two groups on variables associated with the timing of diagnosis and related outcomes.

RESULTS

In population with bipolar I disorder, a significant longer time lapse from the first major mood episode to the confirmed diagnosis was associated with the FE-D group compared to the FE-M group [5.6 (+/-6.1) vs. 2.5 (+/-5.5) years, p<0.001]. FE-D subjects tended to have prior diagnoses of schizophrenia and major depressive disorder while FE-M subjects tended to have prior diagnoses of bipolar disorder and schizophrenia. A significantly higher rate of suicide attempts was associated with the FE-D group compared to the FE-M group (12.7 vs. 1.7%, p<0.001).

CONCLUSION

The results of this study indicate that first-episode depressive polarity is likely to be followed by a considerable delay until an eventual confirmed diagnosis of bipolar I disorder. Given that first-episode depressive patients are particularly vulnerable to unfavorable clinical outcomes such as suicide attempts, a more systematic approach is needed to differentiate bipolar disorder among depressed patients in their early stages.

Two histidine residues in the juxta-membrane cytoplasmic domain of Na+/H+ exchanger isoform 3 (NHE3) determine the set point

Histidine residues in Na+/H+ exchangers are believed to participate in proton binding and influence the Na+/H+ exchanger activity. In the present study, the function of three highly conserved histidines in the juxtamembrane cytoplasmic domain of NHE3 was studied. His-479, His-485, and His-499 were mutated to Leu, Gln or Asp and expressed in an Na+/H+ exchanger null cell line and functional consequences on Na+/H+ exchange kinetics were characterized. None of the histidines were essential for NHE3 activity, with all mutated NHE3 resulting in functional exchangers. However, the mutation in His-475 and His-499 significantly lowered NHE3 transport activity, whereas the mutation in H485 showed no apparent effect. In addition, the pH profiles of the H479 and H499 mutants were shifted to a more acidic region, and lowered its set point, the intracellular pH value above which the Na+/H+ exchanger becomes inactive, by approximately 0.3-0.6 pH units. The changes in set point by the mutations were further shifted to more acidic values by ATP depletion, indicating that the mechanism by which the mutations on the histidine residues altered the NHE3 set point differs from that caused by ATP depletion. We suggest that His-479 and His-499 are part of the H+ sensor, which is involved in determining the sensitivity to the intracellular H+ concentration and Na+/H+ exchange rate.

Constitutively active phosphatidylinositol 3-kinase and AKT are sufficient to stimulate the epithelial Na+/H+ exchanger 3

Phosphatidylinositol 3-kinase (PI 3-kinase) is a cytoplasmic signaling molecule that is recruited to activated growth factor receptors and has been shown to be involved in regulation of stimulated exocytosis and endocytosis. One of the downstream signaling molecules activated by PI 3-kinase is the protein kinase Akt. Previous studies have indicated that PI 3-kinase is necessary for basal Na(+)/H(+) exchanger 3 (NHE3) transport and for fibroblast growth factor-stimulated NHE3 activity in PS120 fibroblasts. However, it is not known whether activation of PI 3-kinase is sufficient to stimulate NHE3 activity or whether Akt is involved in this PI 3-kinase effect. We used an adenoviral infection system to test the possibility that activation of PI 3-kinase or Akt alone is sufficient to stimulate NHE3 activity. This hypothesis was investigated in PS120 fibroblasts stably expressing NHE3 after somatic gene transfer using a replication-deficient recombinant adenovirus containing constitutively active catalytic subunit of PI 3-kinase or constitutively active Akt. The adenovirus construct used was engineered with an upstream ecdysone promoter to allow time-regulated expression. Adenoviral infection was nearly 100% at 48 h after infection. Forty-eight hours after infection (24 h after activation of the ecdysone promoter), PI 3-kinase and Akt amount and activity were increased. Increases in both PI 3-kinase activity and Akt activity stimulated NHE3 transport. In addition, a membrane-permeant synthetic 10-mer peptide that binds polyphosphoinositides and increases PI 3-kinase activity similarly enhanced NHE3 transport activity and also increased the percentage of NHE3 on the plasma membrane. The magnitudes of stimulation of NHE3 by constitutively active PI 3-kinase, PI 3-kinase peptide, and constitutively active Akt were similar to each other. These results demonstrate that activation of PI 3-kinase or Akt is sufficient to stimulate NHE3 transport activity in PS120/NHE3 cells.

An interface with a linear quadrupole ion guide for an electrospray-ion trap mass spectrometer system

A new ion sampling interface for an electrospray ionization 3D ion trap mass spectrometer system is described. The interface uses linear rf quadrupoles as ion guides and ion traps to enhance the performance of the 3D trap. Trapping ions in the linear quadrupoles is demonstrated to improve the duty cycle of the system. Dipolar excitation of ions trapped in a linear quadrupole is used to eject unwanted ions. A resolution of ejection of up to 254 is demonstrated for protonated reserpine ions (m/z 609.3). A composite waveform with a notch in frequency space is used to eject a wide range of matrix ions and to isolate trace analyte ions in a linear quadrupole before ions are injected into the 3D trap. This is useful to overcome space charge problems in the 3D trap caused by excess matrix ions. For trace reserpine in a 500-fold molar excess of poly(propylene glycol) (PPG), it is demonstrated that the resolution and sensitivity of the 3D trap can be increased dramatically with ejection of the excess PPG matrix ions. In comparison to ejection of matrix ions in the 3D trap with a similar broad-band waveform, a 5-fold increase in sensitivity with a 7 times shorter acquisition time was achieved.

XMAP230 is required for normal spindle assembly in vivo and in vitro

XMAP230 is a high molecular mass microtubule-associated protein isolated from Xenopus oocytes and eggs, and has been recently shown to be a homolog of mammalian MAP4. Confocal immunofluorescence microscopy revealed that XMAP230 is associated with microtubules throughout the cell cycle of early Xenopus embryos. During interphase XMAP230 is associated with the radial arrays of microtubules and midbodies remaining from the previous division. During mitosis, XMAP230 is associated with both astral microtubules and microtubules of the central spindle. Microinjection of affinity-purified anti-XMAP230 antibody into blastomeres severely disrupted the assembly of mitotic spindles during the rapid cleavage cycles of early development. Both monopolar half spindles and bipolar spindles were assembled from XMAP230-depleted extracts in vitro. However, spindles assembled in XMAP230-depleted extracts exhibited a reduction in spindle width, reduced microtubule density, chromosome loss, and reduced acetylation of spindle MTs. Similar defects were observed in the spindles assembled in XMAP230-depleted extracts that had been cycled through interphase. Depletion of XMAP230 had no effect on the pole-to-pole length of spindles, and depletion of XMAP230 from both interphase and M-phase extracts had no effect on the rate of microtubule elongation. From these results, we conclude that XMAP230 plays an important role in normal spindle assembly, primarily by acting to stabilize spindle microtubules, and that the observed defects in spindle assembly may result from enhanced microtubule dynamics in XMAP230-depleted extracts.

Efficient diffusive reflector-type diode side-pumped Nd:YAG rod laser with an optical slope efficiency of 55%

We fabricated a compact diode side-pumped Nd:YAG laser with a diffusive reflector, in which the diode laser power is transferred directly into the threefold symmetric diffusive cavity through long narrow slits. With a 7.5% output coupler in a linear resonator, we obtained 62.4-W multimode output power with an optical slope efficiency of 53.4% at a diode power of 182 W, which corresponds to an optical-to-optical efficiency of 34.3%. The optical slope efficiency increased to 55.5% when we used an 11% output coupler. From the leakage power analysis method, the pumping efficiency was measured to be approximately 82%. We discuss the thermal lens and the slope efficiency with respect to absorbed power that is derived from the measured pumping efficiency.