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.

Interpersonal sensitivity and childhood trauma in patients with major depressive disorder, bipolar I, and II disorder

Childhood trauma and interpersonal sensitivity impact the development of mood disorders. In this study, we investigate the association between childhood trauma and interpersonal sensitivity in patients with mood disorders. A total 775 patients (major depressive disorder [MDD, n = 241], bipolar I disorder [BD I, n = 119], and bipolar II disorder [BD II, n = 415]) and 734 controls. For evaluation, we used the Childhood Trauma Questionnaire-Short Form (CTQ) and Interpersonal Sensitivity Measure (IPSM). We examined between-group differences for each subscale in the CTQ and IPSM. Patients with BD II had significantly higher IPSM total scores than patients with MDD, BD I, or controls. The CTQ total score was related to the IPSM total score in all participants and subgroups. Among the CTQ subscales, emotional abuse showed the highest correlation with the IPSM total score, while separation anxiety and fragile inner self showed higher positive correlations with CTQ than the other subscales of IPSM in all patient groups and the control group, respectively. The findings reveal that childhood trauma and interpersonal sensitivity are positively correlated among patients with MDD, BD I, and BD II, and that interpersonal sensitivity is higher in patients with BD II than those with BD I or MDD. Childhood trauma is associated with interpersonal sensitivity, and each trauma type has a different impact on mood disorders. We expect that this study will encourage future research on interpersonal sensitivity and childhood trauma in mood disorders to improve treatment approaches.

Understanding of Depressive Symptomatology across Major Depressive Disorder and Bipolar Disorder: A Network Analysis

Background and Objectives: Depressive symptoms are prominent in both major depressive disorder (MDD) and bipolar disorder (BD). However, comparative research on the network structure of depressive symptoms in these two diagnostic groups has been limited. This study aims to compare the network structure of depressive symptoms in MDD and BD, providing a deeper understanding of the depressive symptomatology of each disorder. Materials and Methods: The Zung Self-Rating Depressive Scale, a 20-item questionnaire, was administered to assess the depressive symptoms in individuals with MDD (n = 322) and BD (n = 516). A network analysis was conducted using exploratory graph analysis (EGA), and the network structure was analyzed using regularized partial correlation models. To validate the dimensionality of the Zung SDS, principal component analysis (PCA) was adopted. Centrality measures of the depressive symptoms within each group were assessed, followed by a network comparison test between the two groups. Results: In both diagnostic groups, the network analysis revealed four distinct categories, aligning closely with the PCA results. "Depressed affect" emerged as the most central symptom in both MDD and BD. Furthermore, non-core symptoms, "Personal devaluation" in MDD and "Confusion" in BD, displayed strong centrality. The network comparison test did not reveal significant differences in the network structure between MDD and BD. Conclusions: The absence of significant differences in the network structures between MDD and BD suggests that the underlying mechanisms of depressive symptoms may be similar across these disorders. The identified central symptoms, including "Depressed affect", in both disorders and the distinct non-core symptoms in each highlight the complexity of the depressive symptomatology. Future research should focus on validating these symptoms as therapeutic targets and incorporate various methodologies, including non-metric dimension reduction techniques or canonical analysis.

Network structure of symptomatology of adult attention-deficit hyperactivity disorder in patients with mood disorders

Patients with mood disorders commonly manifest comorbid psychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD). However, few studies have evaluated ADHD symptoms in this population. The current study aimed to explore the network structure of ADHD symptomology and identify central symptoms in patients with mood disorders. The Korean version of the Adult ADHD Self-Report Scale was used to assess the overall ADHD symptoms in 1,086 individuals diagnosed with mood disorders (major depressive disorder [n = 373], bipolar I disorder [n = 314], and bipolar II disorder [n = 399]). We used exploratory graph analysis to detect the number of communities, and the network structure was analyzed using regularized partial correlation models. We identified the central ADHD symptom using centrality indices. Network comparison tests were conducted with different subgroups of patients with mood disorders, including three mood diagnosis groups, between the patients who met the diagnostic criteria for ADHD [ADHD-suspected, n = 259] in their self-report and the others [ADHD-non-suspected, n = 827], and groups with high [n = 503] versus low [n = 252] levels of depressive state. The network analysis detected four communities: disorganization, agitation/restlessness, hyperactivity/impulsivity, and inattention. The centrality indices indicated that "feeling restless" was the core ADHD symptom. The result was replicated in the subgroup analyses within our clinically diverse population of mood disorders, encompassing three presentations: Patients with suspected ADHD, patients without suspected ADHD, and patients with a high depressive state. Our findings reveal that "feeling restless" is the central ADHD symptom. The treatment intervention for "feeling restless" may thus play a pivotal role in tackling ADHD symptoms in adult patients with mood disorders.

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.

Association between Plasma Metabolic Profiles of the Antidepressant Escitalopram and Clinical Response in Subjects with Depression

Liquid chromatography/electrospray ionization-mass spectrometry revealed plasma metabolic profiles for the antidepressant drug escitalopram (ECTP) and associated clinical responses in subjects with major depressive disorder (MDD). Metabolic profiles contribute to variations in responses to drug treatment of depression. To assess clinical responses and treatment outcomes, we quantified the levels of metabolites, including those of the parent drug, in plasma samples collected at different time points (days 0, 7, 14, and 42) during treatment of seven patients with MDD. Results showed that mean plasma levels of key metabolites and ECTP at day 7 were significantly associated with the clinical response at 42 days after treatment. Statistical analyses, including principal component analysis, of key metabolites and ECTP samples at different time points clearly distinguished the clinical responders from non-responder subjects. Although further validation with a larger cohort is necessary, our results indicate that early improvement and plasma levels of key metabolites and ECTP are predictive of therapeutic treatment outcomes and thus can be used to guide the use of ECTP.

Effect of Home-based Self-administered Transcranial Direct Stimulation in Patients with Mild to Moderate Major Depressive Disorder: A Single-arm, Multicentral Trial

Objective

Although the effects and safety of transcranial direct current stimulation (tDCS) treatment in depressive patients are largely investigated, whether the self-administration of tDCS treatment at patient's home is comparable to clinic-based treatment is still unknown.

Methods

In this single-arm, multi-center clinical trial, 61 patients with mild to moderate major depressive disorder were enrolled. tDCS treatment was delivered at the patient's home once a day, 5 to 7 times a week for 6 weeks, and each session lasted for 30 minutes. The primary outcome was a total Beck-Depression Inventory-II score, and no concurrent antidepressants were used.

Results

The remission rates in both Full-Analysis (FA) (n = 61) and Per-Protocol (PP) (n = 43) groups were statistically significant (FA: 57.4% [0.44-0.70], PP: 62.8% [0.47-0.77]; percent [95% confidence interval]). The degree of depression- related symptoms was also significantly improved in 2, 4, and 6 weeks after the treatment when compared with baseline. There was no significant association between treatment compliance and remission rate in both FA and PP groups.

Conclusion

These results suggest that acute treatment of patient-administered tDCS might be effective in improving the subjective feeling of depressive symptoms in mild to moderate major depressive disorder patients.

Validation of the Short Form of the Mood Instability Questionnaire-Trait (MIQ-T-SF) in the Korean General Population

OBJECTIVE

Mood instability (MI) is a clinically significant trait associated with psychiatric disorders. However, there are no concise measurements to evaluate MI. The initial Mood Instability Questionnaire-Trait (MIQ-T) was developed to fill this gap. The current study aimed to create a short form of MIQ-T (MIQ-T-SF) that measures MI with high validity and reliability in the Korean general population.

METHODS

Of the 59 items in the MIQ-T, 17 items were chosen for the MIQ-T-SF following the factor analysis process. In total, 540 participants completed the MIQ-T-SF. Cronbach's alpha and McDonald's omega were used to evaluate reliability. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to determine construct validity. Concurrent validity was confirmed via comparisons with Personality Assessment Inventory-Borderline Features Scale. Measurement invariance across gender and age groups was confirmed before analyzing differences in scores using Kruskal-Wallis test.

RESULTS

The MIQ-T-SF displayed expected correlations and high internal consistency (α=0.71-0.90, Ωt=0.72-0.92). Using EFA and CFA, a five-factor structure was confirmed. Measurement invariance was supported, and gender differences were observed.

CONCLUSION

The MIQ-T-SF is an accurate and reliable method to detect MI in the Korean general population. The study's results offer new perspectives for future studies on MI.

Korean Validation of the Short Version of the TEMPS-A (Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire) in Patients with Mood Disorders

BACKGROUND AND OBJECTIVES

The Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire (TEMPS-A) is designed to assess affective temperaments. The short version of the TEMPS-A (TEMPS-A-SV) has been translated into various languages for use in research and clinical settings. However, no research has been conducted to validate the Korean version of the TEMPS-A-SV in patients with mood disorders. The goal of this study is to evaluate the reliability and validity of the TEMPS-A-SV in Korean mood disorder patients.

MATERIALS AND METHODS

In this cross-sectional retrospective study, a total of 715 patients (267 patients with major depressive disorder, 94 patients with bipolar disorder I, and 354 patients with bipolar disorder II) completed the Korean TEMPS-A-SV. Cronbach's alpha and McDonald's omega were used to assess the reliability. Exploratory factor analysis (EFA) was also performed. Spearman's correlation coefficient was used to examine associations between the five temperaments. The difference in five temperament scores between the gender or diagnosis groups was analyzed, and the correlation between five temperament scores and age was tested.

RESULTS

The Korean TEMPS-A-SV displayed good internal consistency (α = 0.65-0.88, ω = 0.66-0.9) and significant correlations between the subscales except one (the correlation between hyperthymic and anxious). Using EFA, a two-factor structure was produced: Factor I (cyclothymic, depressive, irritable, and anxious) and Factor II (hyperthymic). The cyclothymic temperament score differed by gender and the anxious temperament score was significantly correlated with age. All the temperaments, except for irritable temperament, showed significant differences between diagnosis groups.

CONCLUSIONS

Overall, the results show that the TEMPS-A-SV is a reliable and valid measurement that can be used for estimating Koreans' affective temperaments. However, more research is required on affective temperaments and associated characteristics in people with mood disorders.

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.

Borderline Personality Pathology in Major Depressive Disorder, Bipolar I and II Disorder, and Its Relationship With Childhood Trauma

OBJECTIVE

Mood disorder and borderline personality pathology (BPP) are frequently comorbid and relate to childhood trauma. We investigated the relationship between childhood trauma and BPP features in mood disorder patients versus controls.

METHODS

A total of 488 mood disorder patients, particularly major depressive disorder (MDD), bipolar I disorder (BD I), and bipolar II disorder (BD II), and 734 controls were included. We examined between-group BPP-related differences and correlated between BPP and childhood trauma using the Childhood Trauma Questionnaire-Short Form (CTQ) and the Personality Assessment Inventory-Borderline Features Scale.

RESULTS

BD II patients showed significantly higher BPP. Emotional abuse and neglect were prominently associated with BPP, while affective instability and negative relationships exhibited a stronger association with childhood trauma. We also found a positive relationship between childhood trauma and BPP in MDD, BD I, and BD II patients.

CONCLUSION

The findings of the present study imply that BPP features are more likely to be found in patients with BD II than BD I or MDD. Mood disorder patients with severe childhood trauma may have higher BPP features. Thus, further study of the relationship between childhood trauma and BPP features could improve the therapeutic approaches and help understand patients with mood disorders.

Korean Validation of the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire

OBJECTIVE

The Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A) has been validated in more than 30 languages and is noted for its broad application in research and clinical settings. This study presents the first attempt to examine the reliability and validity of the TEMPS-A in Korea.

METHODS

A total of 540 non-clinical participants completed the Korean TEMPS-A, which was adapted from the original English version via a comprehensive translation procedure. Reliability was assessed using Cronbach's α, and associations between temperaments were examined using Spearman's correlation coefficient. Exploratory factor analysis (EFA) was performed, and differences in TEMPS-A scores between the gender- and age-based groups were examined using Kruskal-Wallis analysis.

RESULTS

The Korean TEMPS-A exhibited excellent internal consistency (0.70-0.91) and significant correlations between subscales. EFA resulted in a two-factor structure: Factor I (depressive, cyclothymic, irritable, and anxious) and Factor II (hyperthymic). Gender and age group differences were observed.

CONCLUSION

Overall, our results suggest that TEMPS-A is a reliable and valid measure of affective temperaments for the Korean population. This study opens new possibilities for further research on affective temperaments and their related traits.

Efficacy and safety of daily home-based transcranial direct current stimulation as adjunct treatment for bipolar depressive episodes: Double-blind sham-controlled randomized clinical trial

BACKGROUND

Although transcranial direct current stimulation (tDCS) is known to be a promising therapeutic modality for unipolar depression, the efficacy and safety of tDCS for bipolar depressive episodes (BD) are still unknown and clinical trials of home-based tDCS treatment are scarce. As a result, we set out to investigate the efficacy and safety of home-based tDCS for the treatment BD.

METHODS

Participants (n = 64), diagnosed as bipolar disorder as per the diagnostic and statistical manual of mental disorders (DSM-5), were randomly assigned to receive tDCS. Hamilton Depression Rating Scale (HDRS-17) scores were measured at the baseline, week 2, 4, and 6, and home-based tDCS (for 30 min with 2 mA) was self-administered daily.

RESULTS

Of the 64 patients (15.6% bipolar disorder I, 84.4% bipolar disorder II), 41 patients completed the entire assessment. In the intention-to-treat analysis, time-group interaction for the HDRS-17 [F _{(3, 146.36)} = 2.060; p = 0.108] and adverse effect differences between two groups were not statistically significant, except the pain score, which was higher in the active group than the sham group (week 0-2: p < 0.01, week 2-4: p < 0.05, and week 4-6: p < 0.01).

CONCLUSION

Even though we found no evidence for the efficacy of home-based tDCS for patients with BD, this tool was found to be a safe and tolerable treatment modality for BD.

CLINICAL TRIAL REGISTRATION

[https://clinicaltrials.gov/show/NCT03974815], identifier [NCT03974815].

Genome-wide association study of occupational attainment as a proxy for cognitive reserve

Occupational attainment, which represents middle-age cognitive activities, is a known proxy marker of cognitive reserve for Alzheimer's disease. Previous genome-wide association studies (GWAS) have identified numerous genetic variants and revealed the genetic architecture of educational attainment, another marker of cognitive reserve. However, the genetic architecture and heritability for occupational attainment remain elusive. We performed a large-scale GWAS of occupational attainment with 248,847 European individuals from the UK Biobank using the proportional odds logistic mixed model method. In this analysis, we defined occupational attainment using the classified job levels formulated in the UK Standard Occupational Classification system considering the individual professional skill and academic level. We identified 30 significant loci (P < 5 × 10-8); 12 were novel variants, unassociated with other traits. Among them, four lead variants were associated with genes expressed in brain tissues by expression quantitative trait loci mapping from 10 brain regions: rs13002946, rs3741368, rs11654986, and rs1627527. The single nucleotide polymorphism (SNP)-based heritability was estimated to be 8.5% (s.e. = 0.004) and partitioned heritability was enriched in the central nervous system and brain tissues. Genetic correlation analysis showed shared genetic backgrounds between occupational attainment and multiple traits, including education, intelligence, leisure activities, life satisfaction, and neuropsychiatric disorders. In two-sample Mendelian randomization (MR) analysis, we demonstrated that high occupation levels were associated with reduced risk for Alzheimer's disease (OR = 0.78, 95% CI = 0.65-0.92 in inverse variance weighted (IVW) method; OR = 0.73, 95% CI = 0.57-0.92 in the weighted median (WM) method). This causal relationship between occupational attainment and Alzheimer's disease was robust in additional sensitivity analysis that excluded potentially pleiotropic SNPs (OR = 0.72, 95% CI = 0.57-0.91 in the IVW method; OR = 0.72, 95% CI = 0.53-0.97 in the WM method). Multivariable MR confirmed that occupational attainment had an independent effect on the risk for Alzheimer's disease even after taking educational attainment into account (OR = 0.72, 95% CI = 0.54-0.95 in the IVW method; OR = 0.68, 95% CI = 0.48-0.97 in the WM method). Overall, our analyses provide insights into the genetic architecture of occupational attainment and demonstrate that occupational attainment is a potential causal protective factor for Alzheimer's disease as a proxy marker of cognitive reserve.

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.

Atypical Antipsychotics Augmentation in Patients with Depressive Disorder and Risk of Subsequent Dementia: A Nationwide Population-Based Cohort Study

BACKGROUND

While atypical antipsychotic medications are widely used for treating depressive disorders, their long-term effects on the risk of subsequent dementia have not been studied adequately.

OBJECTIVE

To investigate whether the risk of dementia differs according to the use of atypical antipsychotic drugs, and compare the effects of antipsychotic agents on dementia risk in individuals with late-life depressive disorders.

METHODS

A nationwide population-based retrospective cohort study was conducted using data from the National Health Insurance Service-Senior Cohort of South Korea. Atypical antipsychotic dosages were standardized using a defined daily dose, and the cumulative dosage was calculated. Participants were observed from January 2008 to December 2015. Cox proportional hazard regression analysis was used to estimate the hazard ratios.

RESULTS

The cohort included 43,788 elderly adults with depressive disorders: 9,901 participants (22.6%) were diagnosed with dementia. Findings showed that atypical antipsychotics were prescribed to 1,967 participants (4.5%). Compared with non-users, users of atypical antipsychotics experienced a significantly higher risk for dementia with an adjusted hazard ratio (aHR) of 1.541 (95% confidence interval [CI], 1.415-1.678). A cumulative dose-response relationship was observed (test for trend, p < 0.0001). Among atypical antipsychotics, risperidone displayed the highest risk for dementia (aHR 1.767, [95% CI, 1.555-2.009]).

CONCLUSION

In this study of elderly individuals with depressive disorders, atypical antipsychotic use was associated with a significantly higher risk of subsequent dementia. Healthcare professionals should be aware of this potential long-term risk. A limitation that should be mentioned is that we could not exclude patients with bipolar depression.

Emergency department visits for panic attacks and ambient temperature: A time-stratified case-crossover analysis

BACKGROUND

Panic disorder is a common anxiety disorder affecting up to 5% of the population. Although its pathogenesis is unclear, evidence about its association with ambient temperature is limited. We aimed to investigate the association between short-term exposure to increased ambient temperature and exacerbation of panic attacks requiring emergency department visits.

METHODS

From the national emergency database of South Korea, we identified 1,926 patients who presented with panic attacks at the emergency department in Seoul from 2008 to 2014. Using a time-stratified case-crossover design and conditional logistic regression analysis, we compared ambient temperature levels on emergency department visits and correspondingly matched-control days.

RESULTS

Increased ambient temperature levels were significantly associated with panic attacks. The risk of a panic attack increased by 2.2% (95% confidence interval, 0.7-3.8%) per every 1°C increase in temperature. This association was significant after adjusting for air pollutants.

CONCLUSIONS

Our results provide new evidence that short-term exposure to increased ambient temperature may increase the risk of exacerbation of panic attacks. These findings may provide a basis for further research to establish the association between panic attacks and ambient temperature, thus establishing preventive measures for panic attacks.

Age-related differences in the associations among at-risk drinking, alcohol use disorder, and psychological distress across the adult lifespan: a nationwide representative study in South Korea

PURPOSE

To investigate age-related differences in the relationships among at-risk alcohol consumption, alcohol use disorder (AUD), and psychological distress with a special focus on older adults.

METHODS

We used a nationwide cross-sectional study of a representative sample of community-dwelling adults from the Korean Epidemiologic Catchment Area study for psychiatric disorders conducted by door-to-door interviews. The Korean version of the Composite International Diagnostic Interview was applied. Subjects were categorized into four age groups: young-to-middle-aged (20-54 years), near-old (55-64 years), early-old (65-74 years), and late-old (≥ 75 years). The associations among at-risk drinking, alcohol use disorder, and psychological distress were examined according to age groups.

RESULTS

Among a total of 5102 individuals, half of them drank alcohol in the previous year, of whom 20.5% were at-risk drinkers (≥ 100 g/week). Older people were less often diagnosed with AUD than young-to-middle-aged adults with a similar degree of at-risk drinking. They were less likely to meet the DSM-5 AUD criteria in terms of social and vocational role disruption or creation of a physically hazardous situation. However, at-risk drinking showed a stronger association with subjective psychological distress in older adults, particularly in the near-old group (adjusted odds ratio 1.82, 95% confidence interval 1.09-3.03; p = 0.023).

CONCLUSIONS

These findings indicate the importance of screening for mental health problems in older adults, especially near-old adults, who drink more than 100 g of alcohol per week even when they do not satisfy the criteria for a diagnosis of AUD.

Clinical Correlates of Alcohol Use Disorder in Depressed Patients with Unipolar and Bipolar Disorder

OBJECTIVE

Alcohol use disorder (AUD) is one of the most frequent comorbid conditions in mood disorders. We aimed to examine the relationships between clinical phenotypes of acutely depressed subjects and co-occurring AUD.

METHODS

Clinical assessment including diagnosis of mood disorder and co-occurring AUD, the severity of depressive or manic symptoms, and affective temperaments were conducted in 137 subjects suffering from a major depressive episode. According to the presence of AUD, clinical variables were compared between the two groups. Using binary logistic regression models, the effects of mood symptoms and affective temperaments on the risk of AUD were determined.

RESULTS

Severity of manic symptoms, suicidal ideation, and childhood trauma were higher in the AUD group than in the non-AUD group. Scores for irritable and hyperthymic temperament were higher and the score for anxious temperament was lower in the AUD group. In regression models adjusting confounders, anxious temperament was an independent protector against AUD. On the other hand, the diagnosis of bipolar disorder and the irritable manic symptom dimension increased the risk of AUD.

CONCLUSION

Anxious temperament decreased the AUD risk, whereas irritable manic symptoms increased the risk during depression. AUD in mood disorders may be an expression of manic psychopathology.

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.

Psychopathologic structure of bipolar disorders: exploring dimensional phenotypes, their relationships, and their associations with bipolar I and II disorders

BACKGROUND

Given its diverse disease courses and symptom presentations, multiple phenotype dimensions with different biological underpinnings are expected with bipolar disorders (BPs). In this study, we aimed to identify lifetime BP psychopathology dimensions. We also explored the differing associations with bipolar I (BP-I) and bipolar II (BP-II) disorders.

METHODS

We included a total of 307 subjects with BPs in the analysis. For the factor analysis, we chose six variables related to clinical courses, 29 indicators covering lifetime symptoms of mood episodes, and 6 specific comorbid conditions. To determine the relationships among the identified phenotypic dimensions and their effects on differentiating BP subtypes, we applied structural equation modeling.

RESULTS

We selected a six-factor solution through scree plot, Velicer's minimum average partial test, and face validity evaluations; the six factors were cyclicity, depression, atypical vegetative symptoms, elation, psychotic/irritable mania, and comorbidity. In the path analysis, five factors excluding atypical vegetative symptoms were associated with one another. Cyclicity, depression, and comorbidity had positive associations, and they correlated negatively with psychotic/irritable mania; elation showed positive correlations with cyclicity and psychotic/irritable mania. Depression, cyclicity, and comorbidity were stronger in BP-II than in BP-I, and they contributed significantly to the distinction between the two disorders.

CONCLUSIONS

We identified six phenotype dimensions; in addition to symptom features of manic and depressive episodes, various comorbidities and high cyclicity constructed separate dimensions. Except for atypical vegetative symptoms, all factors showed a complex interdependency and played roles in discriminating BP-II from BP-I.

Heritability estimates of individual psychological distress symptoms from genetic variation

BACKGROUND

Psychological distress symptoms are associated with an increased risk of psychiatric disorders and medical illness. Although psychological distress is influenced by environmental factors, such as socioeconomic status, lifetime events, or interpersonal relationships, substantial interindividual variation also exists. However, heritability and genetic determinants of distress are poorly understood.

METHODS

In the Korean Genome and Epidemiology Study sample (n = 12,680), we estimated the heritability of individual psychological distress symptoms using the GCTA-REML method and carried out a genome-wide association study of individual psychological distress symptoms showing significant heritability.

RESULTS

We found three psychological distress items showing significant heritability: subjective well-being (9%), fatigue and appetite (11%), and enjoying daily life (8%). Additionally, we found genome-wide significant associations of rs6735649 located between STEAP3 and C1QL2 on chromosome 2 with subjective well-being (P = 1.32 × 10^-8, odds ratio [OR] = 1.18, 95% confidence interval [CI]: 1.12-1.25) and rs35543418 located between SYT16 and KCNH5 on chromosome 14 with enjoying daily life (P = 1.33 × 10^-8, OR = 1.59, 95% CI: 1.35-1.86).

LIMITATIONS

The lack of replication in independent cohorts and longitudinal assessment of distress may limit generalizability.

CONCLUSIONS

Our results indicate that distress symptoms are partly heritable. Further analysis in larger cohorts investigating gene-environment interactions is required to identify genetic variants that explain the proportion of variation in distress.

Liquid chromatography/mass spectrometry-based plasma metabolic profiling study of escitalopram in subjects with major depressive disorder

Liquid chromatography-mass spectrometry (LC-MS) method revealed the plasma metabolite profiles in major depressive disorder patients treated with escitalopram (ECTP) (n = 7). Depression severity was assessed according to the 17-item Hamilton Depression Rating Scale. Metabolic profiles were derived from major depressive disorder subject blood samples collected after ECTP treatment. Blood plasma was separated and processed in order to effectively extract metabolites, which were then analyzed using LC-MS. We identified 19 metabolites and elucidated their structures using LC-tandem MS (LC-MS/MS) combined with elemental compositions derived from accurate mass measurements. We further used online H/D exchange experiments to verify the structural elucidations of each metabolite. Identifying molecular metabolites may provide critical insights into the pharmacological and clinical effects of ECTP treatment and may also provide useful information informing the development of new antidepressant treatments. These detailed plasma metabolite analyses may also be used to identify optimal dose concentrations in psychopharmacotherapeutic treatment through drug monitoring, as well as forming the basis for response predictions in depressed subjects.

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.

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.

Body mass index-related regional gray and white matter volume reductions in first-episode mania patients

BACKGROUND

We previously reported that overweight/obese first-episode mania patients had reduced white matter (WM) and temporal lobe volumes compared with normal-weight patients. WM reductions are characteristic of early-stage bipolar disorder (BD), whereas temporal lobe reductions are frequently reported later in the illness. These findings thus suggested a testable hypothesis: that the neuropathology of BD is exacerbated with elevated body mass index (BMI).

METHODS

We used voxel-based morphometry to examine the relationship between BMI and regional gray matter (GM) and WM volumes in our sample of 57 euthymic first-episode mania patients and 55 healthy subjects. We hypothesized that elevated BMI in patients, but not healthy subjects, would be associated with volume reductions in frontal, temporal, and subcortical limbic brain regions implicated in the pathophysiology of BD.

RESULTS

At recovery from their first manic episode, patients with higher BMI had GM and WM reductions in the predicted emotion-generating and -regulating regions. In contrast, healthy subjects with higher BMI had reduced occipital lobe GM only. Factorial analyses confirmed significant BMI × diagnosis interactions for the WM reductions. Approximately three-quarters of patients with elevated BMI were overweight rather than obese; thus, weight-related volume reductions were detectable in patients with modestly elevated BMI.

CONCLUSIONS

This is the first hypothesis-driven test of, and supporting evidence for, our theory that elevated BMI is associated with unique brain changes in BD that have a negative impact on regions believed to be vulnerable in the illness. Our results suggest a neurobiological mechanism to explain the well-validated link between obesity and illness severity in BD.

Differential patterns of neuropsychological performance in the euthymic and depressive phases of bipolar disorders

AIMS

Patients with bipolar disorders (BD) show a broad range of neurocognitive impairments. We compared the patterns of neuropsychological performance in depressed and euthymic patients with BD, and explored the state-dependent cognitive markers of bipolar depression.

METHODS

The study participants included 32 BD patients (15 depressed and 17 euthymic) and 42 healthy controls. All of the subjects completed tests that assessed attention, psychomotor speed, verbal and visual memory, and executive functions. Between-group neuropsychological performance differences were examined. Multidimensional scaling (MDS) was used to compare the patterns of cognitive variables in euthymic and depressed BD patients.

RESULTS

Compared to the euthymic BD patients and healthy controls, the depressed BD patients performed lower in verbal memory and executive functions. No significant differences were found between the three groups in attention, psychomotor speed, and visual memory. The depressed BD patients showed a lower level of association between psychomotor speed and the time to initial concept formation than the healthy controls and euthymic BD patients. In contrast, the correlation between word association and verbal memory was stronger in the depressed group than either the control or euthymic groups.

CONCLUSION

The depressed BD patients showed greater impairments in verbal memory and executive functions than the euthymic BD patients. In addition, our study identified a differential pattern of correlations between the cognitive domains of euthymic and depressed BD patients, which suggests the potential role of verbal memory and executive functions as cognitive markers of BD.

Relationship between frontostriatal morphology and executive function deficits in bipolar I disorder following a first manic episode: data from the Systematic Treatment Optimization Program for Early Mania (STOP-EM)

OBJECTIVES

Executive function impairments are a core feature of bipolar I disorder (BD-I), not only present during acute episodes but also persisting following remission of mood symptoms. Despite advances in knowledge regarding the neural basis of executive functions in healthy subjects, research into morphological abnormalities underlying the deficits in BD-I is lacking.

METHODS

Patients with BD-I within three months of sustained remission from their first manic episode (n = 41) underwent neuropsychological testing and a 3T magnetic resonance imaging scan and were compared to healthy subjects matched for age, sex, and premorbid IQ (n = 30). Group dorsolateral prefrontal cortex (DLPFC; Brodmann areas 9 and 46) and caudate volumes were examined and analyzed for relationships with the average score from three computerized tests of executive function: Spatial Working Memory, Stockings of Cambridge, and Intradimensional/Extradimensional Shift.

RESULTS

Right caudate volumes were enlarged in patients (z = 3.57, p < 0.05 corrected). No differences in DLPFC volumes were found. Patients showed large deficits in executive function relative to healthy subjects (d = -0.92, p < 0.001). While in healthy subjects, a larger right (r = +0.39, p < 0.05) and left (r = +0.44, p < 0.05) caudate was associated with better executive function score, in patients, larger right (r = -0.36, p < 0.05) and left (r = -0.34, p < 0.05) volumes correlated with poorer performance.

CONCLUSIONS

Although the etiology of gray matter changes is unknown, volume increases in the right caudate may be an important factor underlying executive function impairments during remission in patients with BD-I.

An FMRI study investigating adolescent brain activation by rewards and feedback

OBJECTIVE

This study aimed to investigate the adolescent brain activation patterns in response to performance feedback (PF), social reward (SR) and monetary reward (MR) and their association with psychological factors.

METHODS

Functional magnetic resonance imaging (fMRI) was performed while middle school boys (n=15) performed tests pertained to PF, SR and MR. The brain activation pattern in each condition was investigated, and the extent of brain activation in each of the three conditions was compared at once.

RESULTS

The caudate and the dorsal prefrontal area were activated in all three conditions. Furthermore, the cuneus showed significantly greater activation in the PF condition than the SR or MR condition. And the self - related areas, such as the right precentral gyrus and paracenral lobule, were more activated in the SR condition than the PF or MR condition. The left middle frontal gyrus was more activated in the MR condition than the PF or SR condition.

CONCLUSION

Not only various reward stimuli but also feedback stimulus might commonly activate dorsal prefrontal and subcortical area in adolescents. Moreover, several different brain activation patterns were also observed in each condition. The results of this study could be applied to planning of learning and teaching strategy for adolescents in various ways.

Verbal and Visual Memory Impairments in Bipolar I and II Disorder

OBJECTIVE

To compare verbal and visual memory performances between patients with bipolar I disorder (BD I) and patients with bipolar II disorder (BD II) and to determine whether memory deficits were mediated by impaired organizational strategies.

METHODS

Performances on the Korean-California Verbal Learning Test (K-CVLT) and the Rey-Osterrieth Complex Figure Test (ROCF) in 37 patients with BD I, 46 patients with BD II and 42 healthy subjects were compared. Mediating effects of impaired organization strategies on poor delayed recall was tested by comparing direct and mediated models using multiple regression analysis.

RESULTS

Both patients groups recalled fewer words and figure components and showed lower Semantic Clustering compared to controls. Verbal memory impairment was partly mediated by difficulties in Semantic Clustering in both subtypes, whereas the mediating effect of Organization deficit on the visual memory impairment was present only in BD I. In all mediated models, group differences in delayed recall remained significant.

CONCLUSION

Our findings suggest that memory impairment may be one of the fundamental cognitive deficits in bipolar disorders and that executive dysfunctions can exert an additional influence on memory impairments.

Symptom structure of antipsychotic-induced obsessive compulsive symptoms in schizophrenia patients

OBJECTIVE

The use of clozapine or other second generation antipsychotics (SGAs) has been reported to produce obsessive compulsive (OC) symptoms as adverse mental affects. However, it is not yet clear if SGA-induced OC symptoms have the same phenomenological characteristics as those displayed in obsessive compulsive disorder (OCD). This study investigated the nature of symptoms and dimensions of SGA-induced OC symptoms in schizophrenia patients, which were then compared with those reported in pure OCD.

METHODS

The study subjects were fifty-one schizophrenia patients with SGA-induced OC symptoms. Symptom evaluation was performed using the Korean version of the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Exploratory factor analysis of symptom categories of Y-BOCS symptom checklist (Y-BOCS-SC) was conducted.

RESULTS

Frequencies of individual symptom categories were comparable to those reported in Korean OCD patients. Five factors (forbidden thoughts, hoarding, cleaning, symmetry, and counting) were generated from 13 main symptom categories, which accounted for 70.7% of the total variance. This factor structure is also remarkably similar to those reported in pure OCD patients. The factor score of 'cleaning' was significantly correlated with the overall severity of OC symptoms (P<0.01).

CONCLUSION

A high level of similarity between the nature of symptoms and dimensions identified in patients with SGA-induced OC symptoms and those revealed in OCD patients suggests a common biological mechanism underlying these two clinical conditions.

Abnormal brain activation of adolescent internet addict in a ball-throwing animation task: possible neural correlates of disembodiment revealed by fMRI

While adolescent internet addicts are immersed in cyberspace, they are easily able to experience 'disembodied state'. The purposes of this study were to investigate the difference of brain activity between adolescent internet addicts and normal adolescents in a state of disembodiment, and to find the correlation between the activities of disembodiment-related areas and the behavioral characteristics related to internet addiction. The fMRI images were taken while the addiction group (N=17) and the control group (N=17) were asked to perform the task composed with ball-throwing animations. The task reflected on either self-agency about ball-throwing or location of a ball. And each block was shown with either different (Changing View) or same animations (Fixed View). The disembodiment-related condition was the interaction between Agency Task and Changing View. Within-group analyses revealed that the addiction group exhibited higher activation in the thalamus, bilateral precentral area, bilateral middle frontal area, and the area around the right temporo-parietal junction. And between-group analyses showed that the addiction group exhibited higher activation in the area near the left temporo-parieto-occipital junction, right parahippocampal area, and other areas than the control group. Finally, the duration of internet use was significantly correlated with the activity of posterior area of left middle temporal gyrus in the addiction group. These results show that the disembodiment-related activation of the brain is easily manifested in adolescent internet addicts. Internet addiction of adolescents could be significantly unfavorable for their brain development related with identity formation.

Predominant recurrence polarity among 928 adult international bipolar I disorder patients

OBJECTIVE

To test the hypothesis that patients with bipolar disorder (BPD) differ demographically and clinically within subgroups based on the predominant-polarity of major recurrences.

METHOD

We tested factors for association with predominantly (≥2 : 1) depressive vs. mania-like episodes with 928 DSM-IV type-I BPD subjects from five international sites.

RESULTS

Factors preliminarily associated with predominant-depression included: electroconvulsive treatment, longer latency-to-BPD diagnosis, first episode depressive or mixed, more suicide attempts, more Axis-II comorbidity, ever having mixed-states, ever married, and female sex. Predominant-mania was associated with: initial manic or psychotic episodes, more drug abuse, more education, and more family psychiatric history. Of the 47.3% of subjects without polarity-predominance, risks for all factors considered were intermediate. Expanding the definition of polarity-predominance to ≥51% added little, but shifting mixed-states to 'predominant-depression' increased risk of suicidal acts from 2.4- to 4.5-fold excess over predominant-mania-hypomania, and suicidal risk was associated continuously with increasing proportions of depressive or mixed episodes.

CONCLUSION

Subtyping by predominant-polarity yielded predictive associations, including the polarity of first episodes and risk of suicide attempts. Such subtyping may contribute to improve planning of clinical care and to biological studies of BPD.

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.

Nonverbal memory and organizational dysfunctions are related with distinct symptom dimensions in obsessive-compulsive disorder

Recent acceptance that obsessive-compulsive disorder (OCD) represents a heterogeneous phenomenon has underscored the need for dimensional approaches to this disorder. However little is known about the relation between neuropsychological functions and symptom dimensions. The purpose of this study was to identify the cognitive deficits correlated with specific symptom dimensions. Thirteen categories in the Yale-Brown Obsessive Compulsive Scale symptom checklist from 144 patients with OCD were analyzed by principal component analysis. Correlations between identified symptom dimensions and neuropsychological functioning, measured by the Boston Qualitative Scoring System, were analyzed. Five factors or dimensions were identified: contamination/cleaning, hoarding, symmetry/ordering, obsessions/checking, and repeating/counting. Dysfunctions in nonverbal memory and organizational strategies were related to the symmetry/ordering dimension and the obsessions/checking dimension, respectively. The results of the present study support a transculturally stable symptom structure for OCD. They also suggest the possibility that nonverbal memory dysfunction and organizational impairment are mediated by distinct obsessive-compulsive dimensions.

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.

Feasibility of a slower lamotrigine titration schedule for bipolar depression: a naturalistic study

The development of a skin rash is often associated with a rapid escalation of lamotrigine dose. We used lamotrigine to treat 259 patients with Diagnostic and Statistical Manual of Mental Disorders, 4th edition, bipolar depression using either the standard titration schedule (n=132) or a slower titration schedule (n=127) and compared the clinical efficacy and safety of both groups. Clinical efficacy of lamotrigine treatment was assessed using changes in the Clinical Global Impression Scale for Bipolar Disorder-Modified scores during the course of the 12-week treatment. A significant reduction of the Clinical Global Impression Scale for Bipolar Disorder-Modified score was observed in both groups and the effect size was large for both groups (standard, 0.75; slower, 0.71). A mixed-effect model of repeated measurement revealed an increased rate of improvement in the standard titration group that was significant during the first 5 weeks (P<0.001) but became nonsignificant by the final 7 weeks of treatment. The statistically significant reduction in the development of rashes (P=0.005) was a major advantage for patients in the slower titration group. Although the standard titration schedule generally led to faster recovery from depressive symptoms, the slower titration schedule may be an option for patients with a high risk of rash development.

Dysfunction in configural face processing in patients with schizophrenia

BACKGROUND

Face recognition has important implications for patients with schizophrenia, who exhibit poor interpersonal and social skills. Previous reports have suggested that patients with schizophrenia have deficits in their ability to recognize faces, and because face recognition relies heavily on information about the configuration of faces, we hypothesized that patients with schizophrenia would have specific problems in processing configural information.

METHODS

We measured the performance of 20 patients with schizophrenia and 20 normal subjects in a face-discrimination task, using upright and inverted pairs of face photographs that differed in featural or configural information.

RESULTS

The patients with schizophrenia showed disproportionately poorer performance in discriminating configural compared with featural face sets.

CONCLUSION

The result suggests that the face-recognition deficit in schizophrenic patients is due to specific impairments in configural processing of faces.

Cortical thinning in obsessive compulsive disorder

Although studies of obsessive-compulsive disorder (OCD) over the last 20 years have suggested abnormalities in frontal-subcortical circuitry, evidences of structural abnormalities in those areas are still imperfect and contradictory. With recent advances in neuroimaging technology, it is now possible to study cortical thickness based on cortical surfaces, which offers a direct quantitative index of cortical mass. Using the constrained Laplacian-based automated segmentation with proximities (CLASP) algorithm, we measured cortical thickness of 55 patients with OCD (33 men and 22 women) and 52 age- and sex-matched healthy volunteers (32 men and 20 women). We found multiple regions of cortical thinning in OCD patients compared to the normal control group. Patients with OCD had thinner left inferior frontal, left middle frontal, left precentral, left superior temporal, left parahippocampal, left orbitofrontal, and left lingual cortices. Most thinned regions were located in the left ventral cortex system, providing a new perspective that this ventral cortical system may be involved in the pathophysiology of OCD.

Effect of cognitive training focusing on organizational strategies in patients with obsessive-compulsive disorder

The purpose of the present paper was to develop a cognitive training program for patients with obsessive-compulsive disorder (OCD) and evaluate its effectiveness. Nine 60-min sessions focusing on the improvement of organizational strategies were given to 15 patients with OCD over a period of 5 weeks. The control group consisted of 15 age- and sex-matched patients also with OCD. The Rey-Osterrieth Complex Figure Test and Korean-California Verbal Learning Test were administered before and after cognitive training. Clinical symptoms were assessed with the Yale-Brown Obsessive-Compulsive Scale. The memory function in the treatment group improved and their clinical symptoms were alleviated after training, compared to those of the control group. Cognitive training of OCD patients not only improved their memory function, but also alleviated their clinical symptoms. Therefore, cognitive training, focusing on the improvement of organizational strategies, could be an effective treatment modality for patients with OCD.

Implicit and explicit memory in patients with obsessive-compulsive disorder: an event-related potential study

The implicit and explicit memory in patients with obsessive-compulsive disorder (OCD) was investigated using the event-related potential (ERP). For the assessment of implicit memory, a lexical decision task was administered. Among a total of 320 words and 140 non-words, 200 words were repeated, while the remaining 120 words and the 140 non-words were not repeated. For explicit memory, a continuous recognition task was administered, in which 280 words were repeated and 100 were not repeated. On the recognition task, both the controls and OCD patients showed more positivity to the old words than to the new words during the 200-600 ms period post-stimulus. Both groups showed faster response time to the old words than to the new words. On the lexical decision task, the controls showed the old/new effect during the 200-500 ms period post-stimulus, while the OCD patients did not. However, OCD patient showed faster response time to the old words than to the new words, although OCD patients showed prolonged response times to the old words compared to the controls. These results indicate that OCD patients have preserved explicit and implicit memory. The absence of old/new effect on ERP in OCD patients was discussed in terms of dysfunction of frontostriatal system, which plays an important role in both OCD and implicit memory.

Increased water diffusivity in the frontal and temporal cortices of schizophrenic patients

Schizophrenia has been suggested to be the result of both macroscopic and microscopic abnormalities in the brain. Although no definitive clinico-pathological correlations have been found to reconcile the many facets inherent in this disorder, the recent development of the magnetic resonance diffusion tensor imaging (DTI) has allowed us to gather useful information regarding the microcircuitry of the brain. Specifically, the apparent diffusion coefficient (ADC) reflects the degree of diffusion barriers and heterosynaptic communication for the brain neurotransmitter. Nineteen patients with DSM-IV schizophrenia and 21 age- and sex-matched control subjects participated in DTI, and the severity of the patients' symptoms was evaluated according to the Positive and Negative Syndrome Scale (PANSS). The ADC values were determined and compared between patients and control subjects via voxel-based morphometry. The results show an increased ADC in the bilateral fronto-temporal regions of the schizophrenic patients, as compared with those of the control subjects. In addition, the ADC values in the area of the right insular were correlated with the negative syndromes from the PANSS. Our findings of increased water diffusivity in the fronto-temporal regions of schizophrenic patients and the correlation between negative symptom scales and the ADC in the right insular region indicate that damaged brain microcircuitry might contribute to the pathophysiology of schizophrenia. These findings contribute towards integrating micro and macrostructural abnormalities and syndromes of schizophrenia.

An MRI study of structural variations in schizophrenia using deformation field morphometry

Magnetic resonance imaging (MRI) has an important role in investigating the changes in brain structure that are associated with schizophrenia. In this study, MRI scans of patients diagnosed with schizophrenia (37 males; 19 females; 17-42 years of age) were compared with those of an age- and sex-matched group of normal subjects (37 males; 19 females; 18-40 years of age). Based on the images of the healthy control subjects, we constructed a representative average brain template. Automated image analysis techniques were used to measure differences in the regional nonlinear deformation fields between the two groups. A deformation field, which measures the spatial transformation to deform a template of brain anatomy to each individual data, was obtained as a three-dimensional displacement vector in each voxel. There was a significantly greater magnitude of the deformation fields in the superior frontal and parietal lobes as well as in the cingulate gyrus connecting both lobes of the patients with schizophrenia than in those of healthy controls, suggesting that these cerebral regions have a significantly higher structural variability in schizophrenia.

Asymmetry analysis of deformable hippocampal model using the principal component in schizophrenia

The hippocampus is thought to play an important role in learning and memory processing, and impairments in memory, attention, and decision making are found commonly in schizophrenia. Although many studies have reported decreases in hippocampal volume in the left hemisphere in schizophrenia, regionally specific hippocampal volume loss has not been revealed consistently using volume analysis. Recently, many studies have analyzed shape asymmetry using 3-D models; however, inconsistent results have been reported, mainly due to methodologic differences. We therefore used an active, flexible, deformable shape model for surface parameterization, and compared shape asymmetry based on principal component analysis (PCA) in the hippocampi of schizophrenic patients with those of the normal controls. Although the overall pattern of the statistical results did not change according to the number of principal components, the reconstructed results based on six major components were much more distinguishable. Although the left hemispheric hippocampal volume was larger than the right hemispheric was in this study, the difference was not significant. In shape asymmetry analysis, the right hemisphere hippocampus was bilaterally larger than the left hemisphere hippocampus was in the head of the superior CA1 and smaller in the tail and head of the inferior CA1. The asymmetry in the schizophrenia group was statistically smaller than that in the control group through reduction of the left hemisphere hippocampus volume.

Fractal dimension of cerebral cortical surface in schizophrenia and obsessive-compulsive disorder

Schizophrenia and obsessive-compulsive disorder (OCD) are assumed to be neurodevelopmental disorders. To examine the cortical patterns in the two disorders, three-dimensional fractal dimension (FD) of skeletonized cerebral cortical surface was estimated from magnetic resonance (MR) images of 50 patients with schizophrenia, 45 patients with OCD and 26 healthy normal controls. The schizophrenic group had a significantly smaller mean FD than OCD group, and the OCD group than normal controls. The FD revealed a significant interaction effect of group-by-hemisphere, and the FD asymmetry index distinguished the schizophrenic group from normal controls. In logistic regression models, the FD and CSF volume correctly classified 95.6% of the schizophrenics from the controls and 88.0% of the patients with OCD from the controls. In the control and schizophrenic groups, the FD was not associated with any of tissue volume measures. In the OCD group, however, the FD was significantly correlated with gray matter tissue volume and intracranial volume (ICV). The results of the present study suggest that three-dimensional FD of cortical surface may be a sensitive indicator for investigation of the structural brain abnormalities in mental disorders, especially those developmentally disturbed. Further studies to explore regional FD changes in mental disorders and clinical implications of the FD including diagnostic value should be performed in the future.