Sex-specific regional grey matter volume correlates of daily activities

Treatment with morning blue light increases left amygdala volume and sleep duration among individuals with posttraumatic stress disorder

Background

Posttraumatic stress disorder (PTSD) is associated with numerous cognitive, affective, and psychophysiological outcomes, including problems with sleep and circadian rhythms. We tested the effectiveness of a daily morning blue-light exposure treatment (BLT) versus a matched amber light treatment (ALT) to regulate sleep in individuals diagnosed with PTSD. Moreover, PTSD is also associated with reliable findings on structural neuroimaging scans, including reduced amygdala volumes and other differences in cortical gray matter volume (GMV) that may be indicative of underlying neurobehavioral dysfunctions. We examined the effect of BLT versus ALT on GMV and its association with sleep outcomes.

Methods

Seventy-six individuals (25 male; 51 female) meeting DSM-V criteria for PTSD (Age = 31.45 years, SD = 8.83) completed sleep assessments and structural neuroimaging scans, followed by random assignment one of two light groups, including BLT (469 nm; n = 39) or placebo ALT (578 nm; n = 37) light therapy daily for 30-min over 6-weeks. Participants wore a wrist actigraph for the duration of the study. After treatment, participants returned to complete sleep assessments and a structural neuroimaging scan. Neuroimaging data were analyzed using the Computational Anatomy Toolbox (CAT12) and Voxel-Based Morphometry (VBM) modules within the Statistical Parametric Mapping (SPM12) software.

Results

The BLT condition produced significant increases in total time in bed and total sleep time from actigraphy compared to the ALT condition, while ALT improved wake after sleep onset and sleep efficiency compared to BLT. Additionally, BLT led to an increase in left amygdala volume compared to ALT but did not affect hypothesized medial prefrontal regions. Finally, within group correlations showed that improvements in sleep quality and nightmare severity were correlated with increases in left amygdala volume over the course of treatment for the BLT group but not the ALT group.

Conclusion

In individuals with PTSD, daily exposure to morning blue light treatment was associated with improvements in objective sleep duration and increased volume of the left amygdala compared to amber placebo light treatment, and changes in amygdala volume correlated with subjective improvement in sleep. These findings suggest that daily morning BLT may provide an important non-pharmacologic adjunctive approach for facilitating sleep and neurobehavioral recovery from PTSD.

Personalized values in life as point of interaction with the world: Developmental/neurobehavioral basis and implications for psychiatry

Behavioral neuroscience has dealt with short-term decision making but has not defined either daily or longer-term life actions. The individual brain interacts with the society/world, but where that point of action is and how it interacts has never been an explicit scientific question. Here, we redefine value as an intrapersonal driver of medium- and long-term life actions. Value has the following three aspects. The first is value as a driving force of action, a factor that commits people to take default-mode or intrinsic actions daily and longer term. It consists of value memories based on past experiences, and a sense of values, the source of choosing actions under uncertain circumstances. It is also a multilayered structure of unconscious/automatic and conscious/self-controlled. The second is personalized value, which focuses not only on the value of human beings in general, but on the aspect that is individualized and personalized, which is the foundation of diversity in society. Third, the value is developed through the life course. It is necessary to clarify how values are personalized through the internalization of parent-child, peer, and social experiences through adolescence, a life stage almost neglected in neuroscience. This viewpoint describes the brain and the behavioral basis of adolescence in which the value and its personalization occur, and the importance of this personalized value as a point of interaction between the individual brain and the world. Then the significance of personalized values in psychiatry is discussed, and the concept of values-informed psychiatry is proposed.

Extracting Apathy From Depression Syndrome in Traumatic Brain Injury by Using a Clustering Method

OBJECTIVE

Depression and apathy are common after traumatic brain injury (TBI), and different intervention strategies are recommended for each. However, a differential diagnosis can be difficult in clinical settings, especially given that apathy is considered to be a symptom of depression. In this study, the investigators aimed to isolate apathy from depression among patients with TBI and to examine whether apathy is exclusively associated with the amount of daily activity, as previously reported in the literature.

METHODS

Eighty-eight patients with chronic TBI completed the Japanese versions of the 21-item Beck Depression Inventory-II (BDI-II) and the Starkstein Apathy Scale (AS). Daily activity was measured with a 24-hour life log. A hierarchical cluster analysis was applied to divide the BDI-II data into separable components, and components' correlations with results of the AS and 24-hour life log scale were evaluated.

RESULTS

The BDI-II and AS revealed that 37 patients (42.0%) had both depression and apathy. BDI-II data were classified into four separate clusters (somatic symptoms, loss of self-worth, affective symptoms, and apathy symptoms). Loss of self-worth and apathy symptoms subscores were significantly positively correlated with total AS score (r=0.32, p=0.002, and r=0.52, p<0.001, respectively). The apathy symptoms subscore was significantly correlated with the amount of daily activity (r=-0.29, p=0.009).

CONCLUSIONS

The findings suggest that the BDI-II can differentiate between apathy and depression among patients with TBI, which is essential when selecting intervention options. Moreover, apathy symptoms predicted patients' real-life daily activity.

Decreased physical activity with subjective pleasure is associated with avoidance behaviors

The main hypothesis for the relation between physical activity and mental health is that autonomous motivation, such as subjective pleasure for the activity, plays an important role. However, no report has described empirical research designed to examine the role of subjective pleasure in the relation between objectively measured physical activity and psychological indexes. We used accelerometers to collect data indicating participants' physical activity intensity during a week. Participants recorded their subjective pleasure of activity per hour. In 69% of them, the individual correlation coefficients between physical activity and pleasure in an hour (an index of Physical Activity-Pleasure; PA-PL) were positive (r = 0.22, 95%Cl = [0.11-0.38]), indicating that pleasant sensations increased concomitantly with increasing physical activity. Conversely, 31% participants exhibited negative values of PA-PL, which means that the increase in physical activity had the opposite effect, decreasing pleasure. Multiple linear regression analysis showed that avoidance/rumination behaviors decreased significantly with increased PA-PL (β = -6.82, 95%CI: [-13.27 to -0.38], p < .05). These results indicate that subjective pleasure attached to the PA is more important than the PA amount for reducing depressive behavior.

Altered thalamic gray matter volume in firefighters with heavy alcohol use

BACKGROUND

Alcohol, a known addictive substance, affects the structural properties of the brain. In this study, we explored associations between alcohol use and gray matter properties among firefighters, who are often exposed to significant occupational stress.

METHODS

Gray matter volume (GMV) was evaluated using voxel-based morphometry in 287 male firefighters (mean age: 48.8 ± 7.7 years). Firefighters were classified into 32 never-drinkers, 162 non-heavy alcohol users, and 93 heavy alcohol users according to their alcohol consumption. GMV was compared between groups, and the correlations between GMV and alcohol use were investigated. A voxel-wise height threshold of p < 0.001 (uncorrected) was used, with small volume correction applied on cluster level.

RESULTS

Heavy alcohol users had lower GMV in the bilateral thalamus than non-heavy alcohol users or never-drinkers. Heavy alcohol users also showed lower GMV in the left insula, compared to other groups. The higher the alcohol consumption among firefighters, the lower the GMV of the right thalamus.

CONCLUSIONS

The results of this study show that heavy alcohol use has an association with lower GMV in several core regions, including the thalamus. When considering the impact of these brain regions on cognitive and behavioral control, our findings suggest a need for concern about heavy alcohol use among firefighters.

Relationship between white matter microstructure and work hours

Human social activities are realized by a synergy of neuronal activity over various regions of the brain, which is supported by their connectivity. In the present study, we examined associations between social activities, represented by work hours, and brain connectivity as quantified using diffusion tensor imaging (DTI). In 483 healthy participants, DTI analysis was performed using 3 T magnetic resonance imaging, and work hours were calculated, considering hours of paid employment (the "Work for Pay" category), hours of housework (the "Work at Home" category), and hours of school-related study (the "Student" category). The correlations between each class of work time and DTI indices were analyzed. The mean diffusivity (MD) values of the anterior limb of the internal capsule (ALIC) and the superior fronto-occipital fasciculus (SFO) were negatively correlated with total work hours (ALIC: r = -0.192, p =  2.3 × 10^-5; SFO: r = -0.161, p =  3.8 × 10^-4). We also found that the MD values of the ALIC and the SFO were correlated with work hours in the Work for Pay category (ALIC: r = -0.211, p =  3.2 × 10^-6; SFO: r = -0.163, p =  3.4 × 10^-4) but not with those in the Work at Home category or the Student category. These results suggest that social activity is associated with the white matter microstructure of the ALIC and the SFO. The main difference between "Work for Pay" and the other two social activities appears to be the type of motivation-for example, external versus internal. Therefore, the white matter microstructure of the ALIC and SFO may be related to externally motivated social activities.