A multimodal study regarding neural correlates of the subjective well-being in healthy individuals.

Although happiness or subjective well-being (SWB) has drawn much attention from researchers, the precise neural structural correlates of SWB are generally unknown. In the present study, we aimed to investigate the associations between gray matter (GM) volumes, white matter (WM) microstructures, and SWB in healthy individuals, mainly young adults using multimodal T1 and diffusion tensor imaging studies. We enrolled 70 healthy individuals using magnetic resonance imaging. We measured their SWB using the Concise Measure of Subjective Well-Being. Voxel-wise statistical analysis of GM volumes was performed using voxel-based morphometry, while fractional anisotropy (FA) values were analyzed using tract-based spatial statistics. In healthy individuals, higher levels of SWB were significantly correlated with increased GM volumes of the anterior insula and decreased FA values in clusters of the body of the corpus callosum, precuneus WM, and fornix cres/stria terminalis. A correlational analysis revealed that GM volumes and FA values in these significant regions were significantly correlated with severity of psychological symptoms such as depression, anxiety, and quality of life. Our findings indicate that GM volumes and WM microstructures in these regions may contribute to SWB, and could be the neural basis for psychological symptom severity as well as quality of life in healthy individuals.

White Matter Correlates of Hostility and Aggression in the Visuospatial Function Network in Patients With Schizophrenia.

Background: Violent acts in patients with schizophrenia are often associated with their hostility and aggression levels. Poor visuospatial processing has been suggested as a possible risk factor of violence in schizophrenia. However, studies investigating the relationship between hostility, aggression, and the visuospatial function have been lacking. Here, we aimed to investigate brain dysconnectivity associated with hostility and aggression in schizophrenia, particularly focusing on the visuospatial function network. Methods: Eighty-eight participants with schizophrenia and 42 healthy controls were enrolled. The visuospatial function network regions of interest were analyzed using Tract-Based Spatial Statistics. The hostility item from the Positive and Negative Syndrome Scale (PANSS), aggressive, and agitated behavior item from the Scale for the Assessment of Positive Symptoms (SAPS), and the Rey Complex Figure Test (R-CFT) were measured. Results: Among the participants with schizophrenia, the SAPS aggressive and agitated behavior scores were significantly correlated with fractional anisotropies (FAs) of the white matter regions in the splenium of the corpus callosum (CC), left posterior thalamic radiations (PTR), and left posterior corona radiata (PCR). Exploratory correlational analysis revealed significant negative correlations between FAs of the splenium of the CC and R-CFT copy and immediate recall scores. In addition, three regions including CC, PTR, and PCR that significantly correlated with the aggression scores showed significant correlations with the total PANSS scores. Conclusion: Our main finding suggests that aggression of patients with schizophrenia may be associated with poor visuospatial ability and underlying white matter dysconnectivity. These may help enhance understanding aggression in patients with schizophrenia.

The interaction effect of early trauma exposure and a diagnosis of panic disorder on cortical thickness.

BACKGROUND: Early trauma (ET) is a risk factor for adult psychiatric disorders. ET exposure is known to cause structural brain alterations, particularly in the fronto-temporo-limbic circuitry. ET-related effects on brain development may differ based on individual characteristics and cause different psychiatric outcomes. We investigated the interaction effect of ET exposure and panic disorder (PD) on cortical thickness. METHODS: Sixty-six participants with PD and 66 healthy controls were enrolled. High-resolution T1-weighted images were acquired, and a whole-brain vertex-based analysis was performed to estimate cortical thickness. The Early Trauma Inventory Self Report-Short Form, Anxiety Sensitivity Inventory-Revised, Panic Disorder Severity Scale, Beck Depression Inventory-II, and Beck Anxiety Inventory were administered. RESULTS: There was a significant interaction between ET exposure and PD on the mean cortical thickness in the bilateral insula and right pars triangularis. An exploratory correlational analysis revealed a positive correlation between the mean cortical thickness in the left insula and severity of anxiety sensitivity to cardiovascular symptoms in participants with PD. LIMITATIONS: Our findings may be affected by recall bias because this study is limited by its retrospective cross-sectional design. CONCLUSIONS: Our findings suggest that ET exposure may affect brain structures differently based on a diagnosis of PD. Furthermore, individual variations in brain alterations after ET may confer trait vulnerability that triggers the development of PD. Future longitudinal studies are warranted to elucidate the neurobiological mechanisms underlying ET and psychiatric outcomes.

Biological Aspects of Aggression and Violence in Schizophrenia.

Although the majority of patients with schizophrenia are not actually violent, an increased tendency toward violent behaviors is known to be associated with schizophrenia. There are several factors to consider when identifying the subgroup of patients with schizophrenia who may commit violent or aggressive acts. Comorbidity with substance abuse is the most important clinical indicator of increased aggressive behaviors and crime rates in patients with schizophrenia. Genetic studies have proposed that polymorphisms in the promoter region of the serotonin transporter gene and in the catechol-O-methyltransferase gene are related to aggression. Neuroimaging studies have suggested that fronto-limbic dysfunction may be related to aggression or violence. By identifying specific risk factors, a more efficient treatment plan to prevent violent behavior in schizophrenia will be possible. Management of comorbid substance use disorder may help prevent violent events and overall aggression. Currently, clozapine may be the only effective antipsychotic medication to repress aggressive behavior. With the current medical field moving toward tailored medicine, it is important to identify vulnerable schizophrenia populations and provide efficient treatment.