Psychiatric disorder as dysfunctional behavioural syndrome is a paradoxical phenomenon that is difficult to explain evolutionarily because moderate prevalence rate, high heritability and relatively low fitness are shown. Several evolutionary genetic models have been proposed to address this paradox. In this paper, I explain each model by dividing it into selective neutrality, mutation-selection balance, and balancing selection hypothesis, and discuss the advantages and disadvantages of them. In addition, the feasibility of niche specialization and frequency dependent selection as the plausible explanation about the central paradox is briefly discussed.

Antidepressants are widely used to treat depression in Korea, however, only a few studies have focused on the provider of the treatment. The aim of the study is to compare the differences between patients who were prescribed antidepressants by psychiatrists and those who were prescribed antidepressants by non-psychiatrists in South Korea. Patients with a diagnosis of depressive disorder who had been newly prescribed antidepressants in 2012 were selected from the Health Insurance Review and Assessment Service database. They were classified into two groups depending on whether they received the antidepressant prescription from a psychiatrist or non-psychiatrist. Sociodemographic, clinical, and depression related cost has been investigated. Treatment resistant depression, which is defined as a failure of two antidepressant regimens to alleviate symptoms, was also investigated. Prescription adequacy was assessed based on whether a regimen was maintained for at least 4 weeks. Among the 834694 patients with pharmaceutically treated depression (PTD) examined in this study, 326122 (39.1%) were treated by psychiatrists. Patients who were treated by psychiatrists were younger and had more psychiatric comorbidities than those treated by non-psychiatrists. They had longer PTD duration (229.3 days vs. 103.0 days, p < 0.05) and a larger proportion of treatment resistant depression (9.3% of PTD) when compared to those patients treated by non-psychiatrists. The patients treated by psychiatrists had a smaller proportion of inadequate antidepressant use compared to those patients in the non-psychiatrist group (44.5% vs. 65.1%, p < 0.05). The costs related to depression corrected with PTD duration were higher in the non-psychiatrist group (32214 won vs. 56001 won, p < 0.05). Patients who receive antidepressants from psychiatrists are patients with more severe, treatment-resistant depression. Psychiatrists prescribe antidepressants more adequately and cost- effectively than non-psychiatrists.

Objectives The purpose of this study was to investigate the differences between adolescents and adults, in the perspective-taking ability, as well as the brain activation patterns during the perspective-taking situation. Methods We recruited healthy adolescents aged 13 years to 15 years (n = 20) and adults aged 19 years to 29 years (n = 20). All the subjects were scanned while performing the perspective-taking task, in which an emotional situation was presented in the form of statements comprising first person, as well as third person perspectives. Differences in brain activation between groups were assessed by contrasting neural activity during the tasks. Results In the between-group analysis, while performing the third-person perspective-taking task, the adolescent group showed greater neural activities in the middle frontal gyrus and precentral gyrus as compared to the adult group. Positive correlation was observed between the activity in the frontal areas (Brodmann area 6/9) and the score of scales related to perspective-taking and social cognition in the adolescent group. Conclusions This study suggests that several frontal brain areas of adolescents needs to be overactivated in order to compensate for low perspective-taking ability when they ought to take another person's point of view.

Objectives Internet gaming disorder (IGD) is associated with attention deficit/hyperactivity disorder (ADHD) or depression etc. We tried to examine the mediating effects of depression in the relationship between ADHD and IGD. Methods This study was conducted on 2000 people who participated in on-line survey among 14-39 year-old men and women in 2017. And we clarified the relationship among IGD, ADHD, and depression and tested the mediation model. The mean and standard deviation of the main variables were calculated and correlation analysis was performed to confirm the relationship among the main variables. In order to test the mediating effect of depression on the relationship between ADHD and IGD, the structural equation model was implemented using AMOS 21 (IBM). Results There were significant correlations among the variables; IGD, ADHD and depression. Depression had a mediating effect 0.23 (95% confidence interval : 0.17-0.28) in the relationship between IGD and ADHD. Conclusions This study showed that depression can mediate ADHD and IGD. Therefore, the evaluation and management of depression and ADHD should be included in the diagnosis and treatment of IGD.

Objectives The objective of this study is to investigate differences in clinical characteristics between female panic disorder (PD) patients with abortion history (PD+A) and without abortion history (PD-A). Methods We examined data from 341 female patients diagnosed with PD. We divided the patients with PD into PD+A (82 patients) and PD-A (259 patients) to compare demographic and clinical characteristics. The following instruments were applied : stress coping strategies, NEO-neuroticism, the Anxiety Sensitivity Index-Revised (ASI-R), the Albany Panic and Phobia Questionnaire (APPQ), the Beck Depression Inventory, the Beck Anxiety Inventory (BAI) and the Sheehan Disability Scale. Results Compared to the PD-A, the PD+A group showed no significant difference in coping strategies. However, significantly higher scores in neuroticism, the ASI-R, the APPQ and the BAI were observed. In terms of health-related disability, the PD+A group did not show significant difference. Conclusions Our results suggest that the PD+A group may differ from the PD-A group in trait markers such as neuroticism and anxiety sensitivity, and abortion history may be associated with panic-related symptom severity. Our study suggests that further consideration is needed on such clinical characteristics in PD patients with abortion history.

Objectives Suicide is a complex phenomenon not only caused by the individual's mental illness and economic situation, but also occurred in sociocultural contexts and relationships around the individual. Therefore, the attitudes, which include collective norms, thoughts and feelings of a population, toward suicide play a fundamental role in the prevention of suicide. Factor structure of Attitudes Toward Suicide (ATTS), developed by Renberg, is also various in different sociocultural contexts. This is the first study to investigate factor structure of ATTS along with nationwide sample of Korean adults. Methods This study analyzed the factor structure and reliability of ATTS in 1500 regionally stratified Korean adults. Exploratory factor analysis was performed by using principal axis factoring and varimax rotation. Results The selection of 33 ATTS items based on internal consistency and communality was conducted. Five factors were analyzed, which were named 'Good reason,' 'Negative gaze,' 'Predictability,' 'Means of escape,' and 'Common secret,' respectively. Explained total variance was 41.94%, and the internal consistency ranged from 0.516 to 0.740. Conclusions Each of the five factors contains different semantic dimensions. Consistent with previous studies, factors containing permissive attitude toward suicide was high in those with history of suicidal thought and of suicide attempt. It is notable that the 'Good reason' showed higher score in elderly. This may be related to socioeconomic or physical adversities which have been considered the major cause of suicide in elderly.

Objectives The aim of this study was to investigate the impact of clinical and psychological factors on the quality of life of children and adolescents with epilepsy and their families. Methods Children and adolescents with epilepsy and their families (n = 63, age range = 6-17 years) completed questionnaires on epilepsy-related variables, quality of life, children's depressive symptoms, children's anxiety, children's behavioral problems, children's attention problems, parental stress, and parental anxiety. Stepwise regression analysis was performed to determine the significant predictive variables that affect quality of life. Results In the correlational analysis, children's attention problems (r = 0.363, p = 0.004), parental anxiety (r = 0.377, p = 0.003), parental stress (r = 0.564, p < 0.001), and children's behavioral problems (r = 0.503, p < 0.001) showed a significant correlation with quality of life. Parental stress (β = 0.415, p = 0.001, adjusted R² = 0.345) and children's behavioral problems (β = 0.285, p = 0.02, adjusted R² = 0.345) were significantly related to the quality of life. Conclusions Clinicians should pay attention to parental stress and children's behavioral problems, which affect quality of life in families with pediatric epilepsy.

Objectives Psychological stress has been known to increase the risk of schizophrenia. Because stress responses are mainly mediated by cortisol, the action of the glucocorticoid receptors (Nuclear Receptor Subfamily 3 Group C Member 1, NR3C1) is possibly related to the pathogenesis of schizophrenia. In this study, we investigated the associations between polymorphisms of NR3C1 and schizophrenia. Methods Four single nucleotide polymorphisms (SNPs) (rs17100236, rs2963155, rs9324924, and rs7701443) of NR3C1 were genotyped in 208 patients with schizophrenia and 339 healthy individuals. A chi-square test was performed to test differences in allele distributions among groups. A multiple logistic regression model was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), and multiple inheritance models to analyze the associations between schizophrenia and SNPs (the dominant, recessive and additive models). Results The minor allele frequencies of two SNPs were significantly higher in the schizophrenia group than in those of the control group (rs2963155 G > A : 0.25 vs. 0.18, p = 0.0066 ; rs7701443 A > G : 0.40 vs. 0.33, p = 0.012). The genotype frequencies of two SNPs were found to be significantly different between patients with schizophrenia and controls in the dominant model (rs2963155 : AG/GG vs. AA, OR = 1.66, 95% CI = 1.16-2.38, p = 0.0055, rs7701443 : AG/AA vs. GG, OR = 1.61, 95% CI = 1.11-2.34, p = 0.01) and the log-additive model (rs2963155 : AG vs. GG vs. AA, OR = 1.54, 95% CI = 1.13-2.10, p = 0.0067). Conclusions This study showed significant associations between NR3C1 polymorphisms and schizophrenia. It suggests that NR3C1 may play a role in the pathogenesis of schizophrenia.