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Introduction Bright light therapy (BLT) has been used for treating seasonal affective disorder, depression and bipolar depression. However, it's precise mechanism remains unclear. Bright light exposure (BL) induces neurogenesis in the adult rat hippocampal dentate gyrus (DG). We hypothesized that BL may induce neurogenesis in the human DG as well. Method A 4-week randomized controlled trial study was conducted, where healthy participants were randomly assigned to a BL group (10,000 lux) or dim light exposure group (DL group; 50 lux). Magnetic resonance imaging was performed at baseline and after 4 weeks. Longitudinal hippocampal subfield segmentation was generated via the FreeSurfer 7.1.1 hippocampal subfields module to evaluate volume of bilateral granule cell and molecular layer of the DG-head and -body. Results Our final sample size was 20, which consisted of BL group (n = 10) and DL group (n = 10). After age and sex adjustment, significant effects of time and group were detected in the left DG-head volume (p = 0.04). In the BL group, the left DG-head volume significantly increased (p = 0.004), whereas no significant volumetric change was observed in the DL group. Conclusions This study revealed that 4-week BL significantly increased left DG-head volume in healthy participants. Thus, neurogenesis might be induced by BL in the human DG, which is a completely new mechanism of BLT.

Aim We aimed to investigate the hypotheses that hyperthymic temperament may be positively associated with self-directedness and self-transcendence with adjustment for relevant factors. Methods Using the database of our previous studies, the data from 111 healthy subjects with scores for both the Temperament and Character Inventory and the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire were secondarily used for the present study. Results Hyperthymic Temperament scores were significantly and positively associated with Self-Transcendence scores, but not with Self-Directedness scores, following adjustment for relevant factors. Despite the lack of association between self-transcendence and self-directedness, cooperativeness was significantly and positively associated with self-transcendence and self-directedness, but not with hyperthymic temperament. Moreover, despite the lack of association between hyperthymic temperament and self-directedness, harm avoidance was significantly and negatively associated with hyperthymic temperament and self-directedness, but not with self-transcendence. Conclusion The present findings suggest that hyperthymic temperament may be positively associated with self-transcendence, but not with self-directedness. Moreover, hyperthymic temperament may be, a selfish and reckless trait, self-transcendence may be altruistic and not reckless, and self-directedness may be altruistic but reckless.

Aim In order to resolve the equivocal relationship between anxious temperament rated by the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego-Autoquestionnaire (TEMPS-A) and harm avoidance rated by the Temperament and Character Inventory (TCI), the present study aimed to investigate whether the anxious temperament scale and the harm avoidance scale are significantly associated with adjustment of relevant factors. Our hypothesis was that anxious temperament might be associated with harm avoidance. Methods From the database of our previous studies, the data of 111 healthy subjects who had both TCI and TEMPS-A scores were extracted for the present study. Two multiple regression analyses were performed: one to predict variance in anxious temperament scores without and with harm avoidance scores, and relevant factors; and another to predict variance in harm avoidance scores without and with anxious temperament scores, and relevant factors. Results Anxious temperament was significantly and positively associated with depressive temperament, irritable temperament, and Hamilton Rating Scale for Depression whereas harm avoidance was significantly and negatively associated with hyperthymic temperament, novelty seeking, persistence, and self-directedness, although both were significantly and positively associated with each other. Conclusion These findings support our hypothesis and suggest that anxious temperament may have 'depressive proneness' whereas harm avoidance may have 'passive proneness.'

The Specific Levels of Functioning Scale (SLOF) has been reported to provide a measure of social function in patients with schizophrenia. The aim of this multi-center study was to determine convergent validity of the Japanese version of SLOF, and if cognitive insight would be associated with social function. Fifty-eight patients with schizophrenia participated in the study. Social function, neurocognition, and daily activity skills were evaluated by the Social Functioning Scale (SFS), Brief Assessment of Cognition in Schizophrenia (BACS) and UCSD Performance-based Skills Assessment-Brief (UPSA-B), respectively. We also assessed cognitive insight with the Beck Cognitive Insight Scale (BCIS). Significant relationships were noted between scores on the SLOF vs. those of the SFS, BACS, UPSA-B, and BCIS. Specifically, the correlation between performance on the UPSA-B and SLOF scores was significantly more robust compared to the correlation between performance on the UPSA-B and scores on the SFS. Similarly, the correlation between scores on the BACS and SLOF tended to be more robust than that between the BACS and SFS. Importantly, while the correlation between scores on the BCIS and SLOF reached significance, it was not so between scores on the BCIS and SFS. The SLOF Japanese version was found to provide a measure of social consequences in patients with schizophrenia. Importantly, this study is the first to indicate the relationship between cognitive insight and social function evaluated by the SLOF. This finding is consistent with the observation that SLOF scores were considerably associated with performances on objective functional measures.

Objectives: Mindfulness is a method of training the regulation of attention with non-judgmental acceptance that is linked to beneficial effects on health. The existential approach supports the uniqueness of each individual and helps to provide meaning to their lives. In this randomized controlled trial, we examined whether mindfulness-based intervention (MBI) and the existential approach could be combined sequentially and whether they operated antagonistically or cooperatively. Methods: One hundred thirty-seven participants aged 20 years or older without any severe mental disorders were randomly assigned (1:1), via an envelope method, to receive either 8-week MBI (N = 68) or 4-week MBI followed by 4-week existential approach (EXMIND) (N = 69). Participants were first allocated to a waiting-list group and subsequently randomized to the MBI group or EXMIND group. The primary outcome was self-compassion scale (SCS) total scores at 0, 4, and 8 weeks during intervention or waiting. The analyses were performed by linear mixed models for both primary and secondary outcomes following the intention-to-treat principle. Results: Both MBI and EXMIND groups had significantly increased SCS total scores compared to those of the waiting group, with mean SCS total scores of 2.3 (SD 3.0) in the MBI group and 2.1 (2.9) in the EXMIND group versus 0.3 (2.2) in the waiting group. Conclusions: Our findings suggest that MBI followed by existential approach are not antagonistic and may have cooperative effects, suggesting that EXMIND may be a useful treatment.

Objective Bright light therapy is widely used as the treatment of choice for seasonal affective disorder. Nonetheless, our understanding of the mechanisms of bright light is limited and it is important to investigate the mechanisms. The purpose of this study is to examine the hypothesis that bright light exposure may increase [18F]-fluorodeoxyglucose (FDG) uptake in olfactory bulb and/or hippocampus which may be associated neurogenesis in the human brain. Method A randomized controlled trial comparing 5-day bright light exposure + environmental light (bright light exposure group) with environmental light alone (no intervention group) was performed for 55 participants in a university hospital. The uptake of [18F]FDG in olfactory bulb and hippocampus using FDG positron emission tomography was compared between two groups. Results There was a significant increase of uptake in both right and left olfactory bulb for bright light exposure group vs. no intervention group. After adjustment of log-transformed illuminance, there remained a significant increase of uptake in the right olfactory bulb. Conclusion The present findings suggest a possibility that 5-day bright light exposure may increase [18F]FDG in the right olfactory bulb of the human brain, suggesting a possibility of neurogenesis. Further studies are warranted to directly confirm this possibility.

Introduction: Lamotrigine is one of several mood stabilizers and its effects for the treatment and prevention of depressive episodes, particularly in bipolar disorder, are generally accepted. Although the findings about a therapeutic window of lamotrigine are yet to be determined, it seems important to obtain information on individual pharmacokinetic peculiarities. This study was conducted to formulate the predictive model of plasma lamotrigine levels. Methods: Using the data of 47 patients whose lamotrigine levels, liver function, and renal function were measured, predictive models of lamotrigine levels were formulated by stepwise multiple regression analyses. The predictive power of the models was compared using another dataset of 25 patients. Results: Two models were created using stepwise multiple regression. The first model was: plasma lamotrigine level (μg/mL)=2.308+0.019×lamotrigine dose (mg/day). The second model was: plasma lamotrigine level (μg/mL)=0.08+0.024×lamotrigine dose (mg/day)+4.088×valproate combination (no=0, yes=1). The predictive power of the second model was better than that of the first model. Discussion: The present study proposes a prompt and relatively accurate equation to predict lamotrigine levels.