Objectives Total intracranial volume (TIV) is a major nuisance of neuroimaging research for interindividual differences of brain structure and function. Authors intended to prove the reliability of the atlas scaling factor (ASF) method for TIV estimation in FreeSurfer by comparing it with the results of manual tracing as reference method. Methods The TIVs of 26 normal children and 26 children with attention-deficit hyperactivity disorder (ADHD) were obtained by using FreeSurfer reconstruction and manual tracing with T1-weighted images. Manual tracing performed in every 10th slice of MRI dataset from midline of sagittal plane by one researcher who was blinded from clinical data. Another reseacher performed manual tracing independently for randomly selected 20 dataset to verify interrater reliability. Results The interrater reliability was excellent (intraclass coefficient = 0.91, p < 7.1e-07). There were no significant differences of age and gender distribution between normal and ADHD groups. No significant differences were found between TIVs from ASF method and manual tracing. Strong correlation between TIVs from 2 different methods were shown (r = 0.90, p < 2.2e-16). Conclusions The ASF method for TIV estimation by using FreeSurfer showed good agreement with the reference method. We can use the TIV from ASF method for correction in analysis of structural and functional neuroimaging studies with not only elderly subjects but also children, even with ADHD.

Objectives Risk taking has been implicated in the development of various psychiatric disorders. Previous studies have indicated that risk taking behavior is associated with high levels of impulsiveness. Risk taking entail uncertain situation that outcome probability is unknown. This study tested impulsivity, intolerance of uncertainty and risk taking behavior. Methods A total of 73 participants completed a test battery comprised of the UPPS-P scale as a psychometric measurement of five dimensions of impulsivity, Intolerance of Uncertainty Scale, and Balloon Analog Risk Task (BART) as a behavioral measure of risk taking. The Pearson correlation analysis was used. Results The sensation seeking factor was positively correlated with BART measure (r = 0.27, p = 0.02). Specifically, the relationship between sensation seeking and BART was significant in females. Conclusions Among the five factors of UPPS-P, only the sensation seeking factor predicts risk taking propensity.

Objectives Circadian rhythms have been known to have associations with psychiatric disorders and personality traits. The present study investigated the relationships between circadian typology and temperaments/characters in a non-clinical Korean population. Methods Two hundred six healthy Korean college students (male 109, female 97) participated in this study. The subjects completed the Composite Scale of Morningness for circadian typology and 140-item Temperament and Character Inventory-Revised-Short version (TCI-RS). Results Multivariate analyses of covariance showed a significant association between chronotypes and temperamental dimensions of the TCI-RS. Morning types were significantly associated with lower harm avoidance and higher persistence and self-directedness dimensions, compared to evening types and intermediate types. No interaction effects between sex and chronotypes were shown for temperamental dimensions. Conclusions The present findings suggest that high persistence and self-directedness characters are related to morning types and high harm avoidance temperament is more related to evening types.

Objectives Previous studies suggest that the cannabinoid receptor 1 (CNR1) gene could be an important candidate gene for schizophrenia. According to linkage studies, this gene is located on chromosome 6q14-q15, which is known to harbor the schizophrenia susceptibility locus (locus 5, SCZ5, OMIM 803175). The pharmacological agent delta-9-tetrahydrocannabinol (${\Delta}$-9-THC) seems to elicit the symptoms of schizophrenia. The association between CNR1 polymorphisms and schizophrenia is actively being investigated, and some studies have linked the AAT-trinucleotide repeats in CNR1 to the onset of schizophrenia. In this study, we have investigated the association between the AAT-trinucleotide repeats in CNR1 and schizophrenia by studying schizophrenia patients and healthy individuals from Korea. Methods DNA was extracted from the blood samples of 394 control subjects and 337 patients diagnosed with schizophrenia (as per the Diagnostic and Statistical Manual of Mental Disorders, fourth edition criteria). After polymerase chain reaction amplification, a logistic regression analysis, with age and gender as the covariates, was performed to study the variations in the AAT-repeat polymorphisms between the two groups. Results In total, 8 types of trinucleotide repeats were identified, each containing 7, 8, 10, 11, 12, 13, 14, and 15 repeats, respectively. $(AAT)_{13}$ allele was most frequently observed, with a frequency of 33.6% and 31.6% in the patient and control groups, respectively. The frequency of the other repeat alleles in the patient group (in the decreasing order) was as follows : $(AAT)_{13}$ 33.6%, $(AAT)_{14}$ 21.6%, $(AAT)_{12}$ 18.5%, and $(AAT)_{7}$ 11.1%. The frequency of the repeat alleles in the control group (in the decreasing order) was as follows : $(AAT)_{13}$ 31.6%, $(AAT)_{14}$ 24.5%, $(AAT)_{12}$ 17.2%, and $(AAT)_{7}$ 11.6%. However, there were no significant differences in the AAT-repeat polymorphisms of the CNR1 gene between the patient group and the control group. Conclusions Although our study revealed no significant association of the AAT-repeat polymorphism of the CNR1 gene with schizophrenia, it will serve as a good reference for future studies designed to examine the cannabinoid hypothesis of schizophrenia.

Objectives Restless legs syndrome (RLS) is a sleep disorder characterized by uncomfortable and unpleasant sensations in the legs and an urge to move the legs, usually at night. The aim of this study is to investigate the incidence of RLS in patients with late life depression and its influence on various clinical outcomes such as severity of depression, sleep quality, cognitive function, and quality of life and accordingly, to elucidate the clinical significance of RLS in patients with late life depression (LLD). Methods This study enlisted 170 depressive patients aged 65 years or older from an outpatient clinic. Structured diagnostic interviews were performed using the Korean version of the Mini-International Neuropsychiatric Interview. All patients completed the questionnaires, including the International RLS Severity Scale, the Korean version of Short-Form 36-Item Health Survey (SF-36), and the Pittsburgh Sleep Quality Index (PSQI). The severity of depression was evaluated by the Korean form of the Geriatric Depression Scale (KGDS) and the level of global cognition was assessed by the Mini-Mental State Examination in the Korean version of The Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (MMSE-KC). Results The incidence of RLS was 17.6% in LLD patients. RLS was more prevalent among the subjects with major depressive disorder (MDD) than those with minor depressive disorder or subsyndromal depressive disorder. The RLS group showed higher score in the KGDS than the Non-RLS group but the difference did not reach the statistical significance (p = 0.095, Student t-test). The mean PSQI score was significantly higher in the RLS group than in the Non-RLS group (p = 0.001, Student t-test). The MMSE-KC score was also lower in the RLS group than in Non-RLS group (p = 0.009, analysis of covariance). But, there was no difference in the score of SF-36 between the RLS group and the Non-RLS group. Conclusions RLS is common in LLD patients, especially in the patients with MDD and is associated with poor sleep quality and cognitive dysfunction, indicating that RLS is clinically significant in patients with LLD. Therefore, RLS should be considered as an important clinical issue in the management of LLD.