Jae Nam Bae

Dorsolateral prefrontal cortex and anterior cingulate cortex white matter alterations in late-life depression

BACKGROUND The dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) are critical for mood regulation. Alterations in the white matter connections of these regions may impair their role in mood regulation and increase the risk of developing depression. This study used diffusion tensor imaging to examine for white matter microstructural abnormalities of these regions and of central white matter structures in late-life depression. METHODS One hundred six elderly depressed subjects and eighty-four elderly nondepressed subjects underwent clinical assessment and diffusion tensor imaging. The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured in regions of interest placed in the white matter of the DLPFC, ACC, corpus callosum, and internal capsule. Differences between groups were assessed, controlling for age, sex, and total cerebral volume. RESULTS After controlling for covariates, depressed subjects had significantly lower FA values in white matter of the right ACC, bilateral superior frontal gyri, and left middle frontal gyrus. There were no significant differences in ADC values. CONCLUSIONS Lower FA, representing lower tissue organization, is observed in depressed elders in the DLPFC and right ACC. These findings support the hypothesis that altered connectivity between brain regions contributes to the risk of depression.

Lifetime and 12-month prevalence of DSM-IV psychiatric disorders among Korean adults.

The objective was to estimate the prevalence and correlates of psychiatric disorders in a nationwide sample of Korean adults. Face-to-face interviews were conducted with the Korean version of Composite International Diagnostic Interview 2.1/DSM-IV (N = 6275, response rate 79.8%). The lifetime and 12-month prevalences for all types of DSM-IV disorders were 33.5% and 20.6%, respectively. Those of specific disorders were as follows: 17.2% and 7.1% for alcohol use disorder, 11.2% and 7.4% for nicotine use disorder, 5.2% and 4.2% for specific phobia, 4.3% and 1.7% for major depressive disorder, and 2.3% and 1.0% for generalized anxiety disorder. Among the sociodemographic variables, widowed status, higher income, and rural residence were the risk factors for both lifetime major depressive disorder and alcohol use disorder after controlling for gender, age, and education. The prevalence of psychiatric disorders was higher than those observed in other East-Asian countries and most European countries, but lower than that in the United States. Alcohol use disorder was particularly high in Korea.

A nationwide survey on the prevalence of dementia and mild cognitive impairment in South Korea.

We investigated the prevalence of dementia and mild cognitive impairment (MCI) and the factors associate with risk of dementia from a representative nationwide sample of Korean elders. 8,199 randomly-sampled Koreans aged 65 years or older were invited to participate in the Phase I screening assessment using Mini-Mental State Examination by door-to-door home visit, and 6,141 subjects (response rate = 74.9%) responded. Among them, 2,336 subjects were invited to participate in the Phase II diagnostic assessment for dementia and MCI, and 1,673 subjects responded (response rate = 71.6%). Diagnostic assessments were administered using the Korean version of the Consortium to Establish a Registry for Alzheimers Disease Assessment Packet (CERAD-K) Clinical Assessment Battery. The CERAD-K Neuropsychological Assessment Battery was used for diagnosing MCI. Age-, gender-, education-, and urbanicity-standardized prevalence of dementia was estimated to be 8.1% (95% CI = 6.9-9.2) for overall dementia and 24.1% (95% CI = 21.0-27.2) for MCI. Alzheimers disease (AD) was the most prevalent type (5.7%) followed by vascular dementia (2.0%). Amnestic subtype (20.1%) was much more prevalent than nonamnestic subtype in MCI (4.0%). Older age, being male, lower education level, illiteracy, smoking, and histories of head trauma or depression were associated with increased dementia risk, and alcohol use and moderately intense exercise were associated with decreased dementia risk. We expect numbers of dementia patients to double every 20 years until 2050 in Korea and expect AD to account for progressively more dementia cases in the future.

Prevalence, correlates, and comorbidities of adult ADHD symptoms in Korea: Results of the Korean epidemiologic catchment area study

We examined the prevalence, correlates, and comorbidities of adult attention-deficit hypersensitivity disorder (ADHD) symptoms in a Korean community using data from the National Epidemiological Survey of Psychiatric Disorders in Korea conducted in 2006. A total of 6081 subjects aged 18 to 59 years participated in this study. Diagnostic assessments were based on the Adult ADHD Self-Report Scale Screener and Composite International Diagnostic Interview administered by lay interviewers. The frequencies of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) disorders, sleep disturbances, and suicidal tendency were compared in the ADHD and non-ADHD groups. Odds ratios and significance levels were calculated. The 6 month prevalence of adult ADHD symptoms was 1.1%. Associations between ADHD symptoms and alcohol abuse/dependence, nicotine dependence, mood disorders, major depressive disorder, bipolar disorder, anxiety disorders, obsessive-compulsive disorder, post-traumatic stress disorder, social phobia, specific phobia, somatoform disorder, sleep disturbances, and suicidality were overwhelmingly positive and significant (P<0.05), after controlling for gender and age. Adult ADHD symptoms are highly associated with substance abuse, mood and anxiety disorders, somatoform disorders, sleep disturbances and suicidality, suggesting that clinicians should carefully evaluate and treat such psychiatric disorders in adults with ADHD symptoms.

Relationships of sleep duration with sociodemographic and health-related factors, psychiatric disorders and sleep disturbances in a community sample of Korean adults

The aim of this study is to examine relationships of sleep duration with sociodemographic and health‐related factors, psychiatric disorders and sleep disturbances in a nationwide sample in Korea. A total of 6510 subjects aged 18–64 years participated in this study. Logistic regression was used to calculate the odd ratios and 95% confidence intervals of the covariates, psychiatric disorders and sleep disturbances across the following sleep duration categories: 5 h or less, 6, 7, 8 and 9 h or more per day. Low levels of education, unemployment and physical illness were associated with sleeping for 5 h or less and 9 h or more. Being older and widowed/divorced/separated, high levels of physical activity, pain/discomfort, obesity and high scores on the General Health Questionnaires were associated with sleeping for 5 h or less. Female, being younger and underweight were associated with sleeping for 9 h or more. Alcohol dependence, anxiety disorder and social phobia were associated significantly with sleeping for 5 h or less and 9 h or more. Other psychiatric disorders were more common in subjects who slept for 5 h or less (e.g. alcohol use disorder, mood disorder, major depressive disorder, dysthymic disorder, obsessive‐compulsive disorder and specific phobia) or 9 h or more (e.g. post‐traumatic stress disorder). In addition, subjects who slept for 5 h or less reported more sleep disturbances than did subjects who slept for 7 h. Short or long sleep is associated with psychiatric disorders and/or sleep disturbance, therefore attention to the mental health of short or long sleepers is needed.

A nationwide survey on the prevalence and risk factors of late life depression in South Korea

OBJECTIVE This study aimed to estimate prevalence rates and risk factors of LLD among a large nationwide sample of Korean elders in South Korea. METHOD Of 8199 randomly sampled Koreans aged 65 years or more, 6018 participated (response rate=73.4%). Using the Korean version of the short form Geriatric Depression Scale (SGDS-K), we classified individual scoring 8 or 9 as having possible depression and those scoring ≥ 10 as having probable depression. RESULTS The age-, gender-, education-, and urbanicity-standardized prevalences were 10.1% (95% CI=9.3-10.8) for possible depression, 17.8% (95% CI=16.8-8.7) for probable depression, and 27.8% (95% CI=26.7-29.0) for overall depression. Poverty, living alone, low education, illiteracy, smoking, history of head trauma, and low Mini Mental Status Examination score were associated with greater risk of depression, while mild alcohol use and moderate to heavy exercise were associated with lower risk of depression. However gender difference in the risk of depression was not found. CONCLUSION LLD is decidedly common in South Korea. It was associated with various sociodemographic and clinical factors, some of which are amendable through policy actions. This study was limited by use of the SGDS-K rather than a standardized clinical interview.

Widespread effects of hyperintense lesions on cerebral white matter structure.

OBJECTIVE Hyperintense lesions are a common finding on neuroimaging and are associated not only with aging, medical illness, and some invasive medical procedures, but also with neurologic and psychiatric morbidity. We hypothesized that hyperintense lesions are associated with alterations in white matter structure beyond the visible lesion boundaries as assessed with diffusion tensor imaging (DTI). SUBJECTS AND METHODS Eighty-two neurologically intact older individuals completed brain MRI with DTI. DTI scans were analyzed using regions of interest placed in normal-appearing white matter to measure fractional anisotropy and diffusivity in the white matter of the frontal lobe, the genu of the corpus callosum, and the internal capsule. Hyperintense lesions volumes were measured separately in subcortical gray matter and anterior white matter through a semiautomated segmentation program. The relationship between lesion volumes and DTI measures was examined while controlling for patient age, patient sex, and total cerebral volume. RESULTS Greater anterior white matter lesion volumes were associated with higher diffusivity and lower anisotropy in the white matter of the dorsolateral prefrontal cortex and with higher diffusivity of the internal capsule and white matter lateral to the anterior cingulate cortex. Gray matter lesion volumes were associated with higher diffusivity in the genu of the corpus callosum and the internal capsule. CONCLUSION Ischemic hyperintense lesions are associated with widespread effects on the structure of the frontal lobe white matter and central white matter structures. This may reflect effects of lesions on neural circuits or identification of white matter changes that have not yet become visible on conventional MRI.

Prevalence of DSM-IV major mental disorders among Korean adults: A 2006 National Epidemiologic Survey (KECA-R)

OBJECTIVES The aim of this study was to estimate the prevalence of the DSM-IV major mental disorders in the Korean population using the Korean version of Composite International Diagnostic Interview (K-CIDI). METHODS The Korean Epidemiologic Catchment Area study Replication (KECA-R) was conducted between August 2006 and April 2007. The sampling of the subjects was carried out across 12 catchment areas using a multistage, cluster sampling design. The target population included all eligible community dwelling residents aged 18-64 years. Face-to-face interviews were conducted using the K-CIDI based on the DSM-IV. RESULTS A total of 6510 participants completed the interview (response rate=81.7%). The lifetime and 12-month prevalence rates for DSM-IV major mental disorders were 29.0% and 16.9%, respectively. Those of specific disorders were as follows: (1) alcohol use disorder, 16.2% and 5.6%; (2) nicotine use disorder, 9.0% and 6.0%; (3) specific phobia, 3.8% and 3.4%; (4) major depressive disorder, 5.6% and 2.5%; and (5) generalized anxiety disorder, 1.6% and 0.8%. Additionally, data related to nicotine and alcohol use disorder revealed a very high male to female ratio. Further, mood and anxiety disorders were more prevalent in females than in males. CONCLUSION The prevalence of major mental disorders was high. In comparison with the studies performed in other countries, notable differences were observed with respect to the distribution of mental disorders in Korea.

Prevalence and Correlates of DSM-IV Mental Disorders in South Korean Adults: The Korean Epidemiologic Catchment Area Study 2011

Objective The aim of this study was to estimate the prevalence and correlates of mental disorders in Korean adults. Methods Door to door household surveys were conducted with community residents aged 18-74 years from July 19, 2011, to November 16, 2011 (n=6,022, response rate 78.7%). The sample was drawn from 12 catchment areas using a multistage cluster method. Each subject was assessed using the Korean version of the World Health Organization Composite International Diagnostic Interview (CIDI) based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Results Lifetime and 12-month prevalence estimates were as follows: alcohol use disorders, 13.4% and 4.4%, respectively; nicotine use disorders, 7.2% and 4.0%, respectively; anxiety disorders, 8.7% and 6.8%, respectively; and mood disorders, 7.5% and 3.6%, respectively. The prevalence rates of all types of DSM-IV mental disorders were 27.6% and 16.0%, respectively. Being female; young; divorced, separated, or widowed; and in a low-income group were associated with mood and anxiety disorders after adjustment for various demographic variables, whereas being male and young were associated with alcohol use disorders. Higher income was not correlated with alcohol use disorder as it had been in the 2001 survey. Conclusion The rate of depressive disorders has increased since 2001 (the first national survey), whereas that of anxiety disorders has been relatively stable. The prevalence of nicotine and alcohol use disorders has decreased, and the male-to-female ratio of those with this diagnosis has also decreased.

Segmented volumes of cerebrum and cerebellum in first episode schizophrenia with auditory hallucinations

The volumes of cerebral and cerebellar regions were measured in first episode schizophrenic patients with (n = 17) and without (n = 8) auditory hallucinations. Magnetic resonance images of cerebral and cerebellar regions were segmented into gray and white fractions using an algorithm for semiautomated fuzzy tissue segmentation. They were defined by using the semiautomated Talairach atlas-based parcellation method. Patients with auditory hallucinations showed larger temporal white matter, frontal gray matter, and temporal gray matter volumes than patients without auditory hallucinations. These findings suggest that auditory hallucinations in schizophrenic patients may be associated with neuropathological abnormalities in frontal and temporal brain regions.