Attention deficit hyperactivity disorder (ADHD) is a common childhood psychiatric disorder. Recently, it has been suggested that brain-derived neurotropic factor (BDNF) may play a role in the pathogenesis of ADHD. Our aim of this review is to understand the physiological functions of BDNF and its potential relationship with ADHD and therapeutic approaches of ADHD. Searches were conducted in Pubmed and Research Information Service System (RISS). In this review, we summarized important literatures for the physiological functions of BDNF in neurodevelopment, change of serum BDNF level in ADHD, association of BDNF polymorphism and ADHD and potential association of treatment of ADHD with serum BDNF level. Further studies are required to more clearly understand the source and the role of BDNF in ADHD and to develop BDNF based-ADHD treatement.

Objectives The aim of this study was to evaluate the psychopathological features such as depression and anxiety in schizophrenics with obsessive-compulsive symptoms (OCS) as well as the severity of OCS according to duration of schizophrenia. Methods We randomly selected sixty four inpatients with schizophrenia. We classified the patients into two groups (OCS group, non-OCS group) according to the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). Clinical and demographic features were evaluated. To assess OCS, Y-BOCS were performed. The Korean version of the Positive and Negative Syndrome Scale(K-PANSS), the Brief Psychiatric Rating Scale (BPRS), the Korean version of the Calgary Depression Scale for Schizophrenia (K-CDSS), the Beck Anxiety Inventory (BAI) and the Satisfaction With Life Scale (SWLS) were conducted. Independent t-test and chi-square test were conducted to compare the two groups. Pearson correlation analysis was performed to examine the relationship between the duration of schizophrenia and the Y-BOCS score. Results The Y-BOCS, K-CDSS, and BAI scores were higher in the OCS group. There was a significant correlation between the duration of schizophrenia and the Y-BOCS score. Conclusions Anxiety and depression symptoms were severe in the OCS group. In addition, the results of this study indicate that the longer duration of schizophrenia, the more severe the OCS. Therefore, the evaluation of OCS in schizophrenics should be accompanied by treatment intervention.

Objectives Dopamine dysregulation has been regarded as one of the core pathologies in patients with schizophrenia. Since dopamine synthesis capacity has found to be inconsistent in patients with schizophrenia, current classification of patients based on clinical symptoms cannot reflect the neurochemical heterogeneity of the disease. Here we performed new subtyping of patients with first-episode psychosis (FEP) through biotype-based cluster analysis. We specifically suggested basal ganglia structural changes as a biotype, which deeply involves in the dopaminergic circuit. Methods Forty FEP and 40 demographically matched healthy participants underwent 3T T1 MRI. Whole brain parcellation was conducted, and volumes of total 6 regions of basal ganglia have been extracted as features for cluster analysis. We used K-means clustering, and external validation was conducted with Positive and Negative Syndrome Scale (PANSS). Results K-means clustering divided 40 FEP subjects into 2 clusters. Cluster 1 (n = 25) showed substantial volume decrease in 4 regions of basal ganglia compared to Cluster 2 (n = 15). Cluster 1 showed higher positive scales of PANSS compared with Cluster 2 (F = 2.333, p = 0.025). Compared to healthy controls, Cluster 1 showed smaller volumes in 4 regions, whereas Cluster 2 showed larger volumes in 3 regions. Conclusions Two subgroups have been found by cluster analysis, which showed a distinct difference in volume patterns of basal ganglia structures and positive symptom severity. The result possibly reflects the neurobiological heterogeneity of schizophrenia. Thus, the current study supports the importance of paradigm shift toward biotype-based diagnosis, instead of phenotype, for future precision psychiatry.