Depression has a relatively high lifetime prevalence rate in spite of a genetic influence on its etiology and a high mortality rate in untreated cases. This suggests the possibility that depression gives us evolutionary benefits which we do not exactly know yet. There have been several hypotheses which tell us what evolutionary advantages depression could give us. The psychic pain hypothesis considers sad or depressed mood as a negative reward just like physical pain which we have to avoid for our protection and survival. The social rank hypothesis holds that depressed mood is very similar to the emotional state of the defeated in social competition which prevents him from further protesting or fighting that might cause additional damage to him. The inclusive fitness hypothesis views suicide as a sacrifice phenomenon to contribute to inclusive fitness. These hypotheses gives us new insights into mood disorders and also some suggestions about the conditions in which depressed mood or suicidal behaviors increase and the ways to reduce them.

Objectives The objective of this study is to investigate differences of clinical characteristics between a healthy female control group and female panic disorder (PD) patients with early sexual abuse history (PD+S) and without early sexual abuse history (PD-S). Methods We examined data from 83 patients diagnosed with PD and 20 healthy control subjects. We divided the patients with PD into PD+S (32 patients) and PD-S (51 patients) to compare demographic and clinical characteristics. The following instruments were applied: the Stress coping strategies, the Beck Depression Inventory (BDI), the Panic Disorder Severity Scale, the Anxiety Sensitivity Index-Revised (ASI-R), the Albany Panic and Phobia Questionnaire (APPQ) and the NEO-neuroticism. Results Compared to the PD-S, the PD+S group showed higher scores in neuroticism and the APPQ. And, in the PD+S group, the scores of neuroticism were correlated with the ASI-R and APPQ subscale scores and the APPQ total scores were associated with the scores of BDI. Conclusions This study shows that female PD+S patients have higher scores in neuroticism and the APPQ than the PD-S group, and these factors are associated with the panic-related symptoms severity. It emphasizes the need of specific strategies considering the childhood abuse history such as early sexual abuse in clinical approach among patients with PD.

Objectives To determine the relationship between the Alu insertion/deletion (I/D) polymorphism in the tissue-type plasminogen activator (tPA) gene and the clinical outcome of mirtazapine treatment in Korean major depressive disorder (MDD) patients. Methods We enrolled 422 patients in this study. Symptoms were evaluated using the 21-item Hamilton Depression Rating (HAMD-21) Scale. After 1, 2, 4, and 8 weeks of mirtazapine treatment, the association between the Alu I/D polymorphism in the tPA gene and remission/response outcomes were evaluated. Results The proportion of I/I homozygotes in responders was higher than that in non-responders, whereas the proportion of D/D homozygotes in responders was lower than that in non-responders at 8 weeks of treatment (p = 0.032, OR = 1.57). The percentage decline of HAMD-21 scores in I allele carriers was larger than that of D/D homozygotes at 2 and 8 weeks of treatment (p = 0.035 and 0.007, respectively). I allele carriers were associated with remission at 8 weeks of treatment (p = 0.047, OR = 2.2). Conclusions These results show that treatment response and remission to mirtazapine were associated with the Alu I/D polymorphism of the tPA gene. This suggests the Alu I/D polymorphism may be a potential genetic marker for the prediction of therapeutic response to mirtazapine treatment in patients with MDD.

Objectives According to previous studies, the cannabinoid receptor 1 (CNR1) gene could be an important candidate gene for schizophrenia. Some studies have linked the (AAT)n trinucleotide repeat polymorphism in CNR1 gene with the risk of schizophrenia. Meanwhile, smooth pursuit eye movement (SPEM) has been regarded as one of the most consistent endophenotypes of schizophrenia. In this study, we investigated the association between the (AAT)n trinucleotide repeats in CNR1 gene and SPEM abnormality in Korean patients with schizophrenia. Methods We measured SPEM function in 167 Korean patients with schizophrenia (84 male, 83 female) and they were divided according to SPEM function into two groups, good and poor SPEM function groups. We also investigated allele frequencies of (AAT)n repeat polymorphisms on CNR1 gene in each group. A logistic regression analysis was performed to find the association between SPEM abnormality and the number of (AAT)n trinucleotide repeats. Results The natural logarithm value of signal/noise ratio (Ln S/N ratio) of the good SPEM function group was $4.34{\pm}0.29$ and that of the poor SPEM function group was $3.21{\pm}0.70$. In total, 7 types of trinucleotide repeats were identified, each containing 7, 10, 11, 12, 13, 14, and 15 repeats, respectively. In the patients with $(AAT)7$ allele, the distributions of the good and poor SPEM function groups were 18 (11.1%) and 19 (11.0%) respectively. In the patients with $(AAT)_{10}$ allele, $(AAT)_{11}$ allele, $(AAT)_{12}$ allele, $(AAT)_{13}$ allele, $(AAT)_{14}$ allele and $(AAT)_{15}$ allele, the distributions of good and poor SPEM function groups were 13 (8.0%) and 12 (7.0%), 4 (2.5%) and 6 (3.5%), 31 (19.8%) and 35 (20.3%), 51 (31.5%) and 51 (29.7%), 36 (22.2%) and 45 (26.2%), 9 (5.6%) and 4 (2.3%) respectively. As the number of (AAT) n repeat increased, there was no aggravation of abnormality of SPEM function. Conclusions There was no significant aggravation of SPEM abnormality along with the increase of number of (AAT)n trinucleotide repeats in the CNR1 gene in Korean patients with schizophrenia.

Objectives There were previous studies which indicated that attitude toward suicide is able to influence the suicide outcome in both individual and group levels. In regard to the highest suicide rate in Korea, our study aims to explore the influence that attitude toward suicide has on suicide by comparing the national attitude towards suicide with a representative sample of the general population. Methods The target population was 20- to 59-year-old adults from South Korea, Japan, and the United States. The panel data were divided according to gender, age, and residential area of individuals, and an email with a hyperlink to our web survey was sent to the randomly selected participants in each stratum. To measure the perceptual differences about suicide in different cultures, this study adopted the Attitudes Toward Suicide questionnaire. Results A total of 2247 subjects in three countries participated in this study. According to results from factor analysis, there were different structure of factors and included items within factors in the three countries : five factors with nineteen items in South Korea, five factors with nineteen items in the United States, and five factors with twenty-five items in Japan. With regard to permissive attitude toward suicide, the mean value of permissiveness was not significantly different among countries, but permissiveness according to education level, gender, and marital status was different in each country. Conclusions This study is the first nationwide comparative study about attitude toward suicide with a representative sample. Our findings suggest that permissive attitude toward suicide influence the suicide phenomenon in each country ; however, its impact is not a mean score of permissiveness, but the detailed difference by various demographics.

Objectives We investigated whether the catechol-O-methyltransferase (COMT) and serotonin related gene polymorphisms may be associated with agoraphobia in patients with panic disorder in Korea. Methods The COMT gene (rs4680), 5-hydroxytryptamine (serotonin) transporter linked polymorphic region (5-HTTLPR) gene (rs25531), serotonin receptor 1A (HTR1A) gene (rs6295) genotypes were analyzed in 406 patients with panic disorder and age-sex matched 206 healthy controls. Patients with panic disorder were dichotomized by the presence of agoraphobia. The following instruments were applied : the Beck Depression Inventory, the Beck Anxiety Inventory, the Panic Disorder Severity Scale. Results There was a significant difference in the distribution of 5-HTTLPR genotype between panic patients with agoraphobia and without agoraphobia (p = 0.024). That is, the panic patients with agoraphobia had a significant excess of the less active 5-HTTLPR allele (S allele). (p = 0.039) Also, we replicated previous western reports which indicated a significant difference in the distribution of COMT genotype between the patients with panic disorder and the healthy controls (p = 0.040). However, no significant associations of agora-phobia or panic disorder with HTR1A gene polymorphisms were found. Conclusions This result supports that the COMT polymorphisms may be associated with panic disorder and suggests that the 5-HTTLPR polymorphisms may play a role in the pathogenesis of agoraphobia in the Korean patients with panic disorder.

Objectives The purpose of this study was to investigate the relationships among circadian types, depressive mood and internet addiction and to identify the mediating effect of depressive mood between circadian types and internet addiction in Korean College Students. Methods A total of 2632 participants completed questionnaires, which included the Korean translation of the Composite Scale of Morningness (CSM), the Patient Health Questionnaire (PHQ-9), and the Korean version of the Internet Addiction Test (KIAT). Statistical analyses were done using correlation analysis, analysis of covariance and multiple linear regression. Results The CSM score was negatively associated with the PHQ-9 score (r = -0.226, p < 0.001) and the KIAT score (r = -0.218, p < 0.001). The eveningness group showed higher scores in depressive mood and internet addiction than the morningness group (p < 0.001). Depressive mood showed a partial mediating effect between circadian types and internet addiction (${\beta}=0.255$, p < 0.001). Conclusions Internet addiction was associated with circadian types and depressive mood. These results suggest that depression and circadian rhythm management would contribute to the prevention of internet addiction.

Objectives This study was conducted to investigate the possibility of neurological soft signs as an endophenotype for schizophrenia by examining neurological soft signs in patients, their unaffected siblings and normal comparison subjects. Methods The study sample consisted of 32 patients, 25 of their unaffected siblings and 30 normal comparison subjects. Neurological soft signs were evaluated using the Cambridge Neurological Inventory Part 2. soft sign assessment. Results The patients were significantly more impaired than normal comparison subjects (p = 0.047) on primitive reflex. The patients were significantly more impaired than siblings (p = 0.004) and normal comparison subjects (p = 0.021) on motor coordination. The siblings performed better on sensory integration than the patients (p = 0.020) and normal comparison subjects (p = 0.036). Conclusions This study suggests that neurological soft signs might be a potential biomarker for schizophrenia, but might not be an endophenotype for schizophrenia.

Objectives Treatment response of bipolar disorders (BDs) to long-term mood stabilizers maintenance has not been well explored because of complicated clinical and treatment courses. This study aims at investigating long-term clinical response of BDs to lithium and/or valproate in a naturalistic setting of a tertiary-care university-affiliated hospital. Methods Subjects were 65 patients with bipolar I (BD-I) disorders who had been treated with lithium and/or valproate for more than two years at single bipolar disorder clinic. Long-term response to the best treatment based on treatment algorithms and the current clinical standard of care was retrospectively evaluated using the Alda Scale and the Clinical Global Impression Scale for use in bi-polar illness (CGI-BP). Patients were classified into full responder and partial/non responder groups based on the total score of the Alda Scale with the cut-off score generated from the frequentist mixture analysis of the authors' previous study. Results The mean duration of treatment with the index medication was 69.2 months. Baseline demographic and clinical characteristics were not different among three mood stabilizer groups (valproate, lithium, and combination groups). Twenty-one subjects were classified into full responder group (32.3%). Treatment response assessed by the Alda Scale and CGI-BP scores was not different between lithium and valproate groups. The Alda Scale scores were well correlated with the CGI-BP scores (p < 0.05). Conclusions One third of the patients showed a full response to the long-term lithium and/or valproate treatment in BD-I. The degree of response was similar between lithium and valproate groups.

Objectives Obsessive-compulsive disorder (OCD) and schizophrenia have many common clinical and neurocognitive features. However, not all of them share the same underlying mechanism. The aim of this study was to discover evidences that indicate a pathophysiological mechanism specific to OCD by comparing correlations of quantitative electroencephalography (QEEG) patterns and neurocognitive function in patients with OCD and schizophrenia. Methods Resting-state QEEG data of total 265 patients were acquired retrospectively and parameters such as absolute power, relative power and peak frequency were analyzed from the data. Stroop test and Trail Making Test results as well as demographic features were reviewed for this study. The correlation of neurocognitive functions and brain electrical activities in each group were assessed and compared by correlation analysis. Results Compared with the OCD group, the schizophrenia group performed poorly in neurocognitive tests. Mean values of QEEG parameters in patients with OCD and schizophrenia did not show significant differences. Both absolute and relative power of alpha rhythm in central and frontal regions showed significant positive correlation with Stroop test results in OCD patients. Conclusions Findings in this study shows distinctive correlations between frontal executive dysfunction and frontal alpha rhythm in the OCD patients, both of which might be a candidate for endophenotype underlying obsessive rumination.

Objectives Although forgetfulness is a common complaint among menopausal depressed women, there is still a debate about the relationship between memory impairment and menopause. The aim of this study is to examine whether menopause is related to cognitive decline among women with depressive disorders. We hypothesized that postmenopausal depressed women show generally poorer performance than premenopausal depressed women on various cognitive function tests. Methods With a retrospective chart review, we identified a total of 87 female patients (45 premenopausal patients and 42 postmenopausal patients) who were hospitalized with depressive disorders from 2000 to 2016. Demographic and clinical variables and cognitive test results were compared between two groups. Results Education year is longer in premenopausal group than postmenopausal group whereas clinical characteristics (illness duration, recurrence, and symptom severity) and mean Intelligence Quotient (IQ) were similar between two groups. The postmenopausal group took longer time for Bender-Gestalt Test (BGT) recall, Trail Making Test (TMT)-A, and TMT-B than the premenopausal group. After controlling for age and education, significant difference was remained for BGT recall (p = 0.029). Conclusions Postmenopausal state may be related with decline of visuospatial memory function, in particular, among depressed female patients. Other areas of cognitive function including complex attention, verbal memory, auditory memory, and working memory might be interpreted while considering age and education level.