思春期後期の閾値下うつにおける抑うつ症状の推移とうつ病発症リスクに関するコホート研究

広島大学(Hiroshima University)博士(医学)Doctor of Philosophy in Medical Sciencedoctora

Effects of behavioural activation on the neural circuit related to intrinsic motivation

[Background] Behavioural activation is an efficient treatment for depression and can improve intrinsic motivation. Previous studies have revealed that the frontostriatal circuit is involved in intrinsic motivation; however, there are no data on how behavioural activation affects the frontostriatal circuit. [Aims] We aimed to investigate behavioural activation-related changes in the frontostriatal circuit. [Method] Fifty-nine individuals with subthreshold depression were randomly assigned to either the intervention or non-intervention group. The intervention group received five weekly behavioural activation sessions. The participants underwent functional magnetic resonance imaging scanning on two separate occasions while performing a stopwatch task based on intrinsic motivation. We investigated changes in neural activity and functional connectivity after behavioural activation. [Results] After behavioural activation, the intervention group had increased activation and connectivity in the frontostriatal region compared with the non-intervention group. The increased activation in the right middle frontal gyrus was correlated with an improvement of subjective sensitivity to environmental rewards. [Conclusions] Behavioural activation-related changes to the frontostriatal circuit advance our understanding of psychotherapy-induced improvements in the neural basis of intrinsic motivation. [Declaration of interest] None.This work was supported by a Grant-in-Aid for Scientific Research on Innovative Areas from Japan Society for the Promotion of Science, JSPS (grants 16H06395 and 16H06399), and grant 23118004 from the Ministry of Education, Culture, Sports, Science and Technology, Japan. This work was partially supported by the programme for Brain Mapping by Integrated Neurotechnologies for Disease Studies (Brain/MINDS) by Japan Agency for Medical Research and Development, AMED (grant 15dm0207012h0002) and Integrated Research on Depression, Dementia and Development Disorders by AMED (grant 16dm0107093h0001). The funders had no role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation or review of the manuscript or decision to submit the manuscript for publication

Transition of the psychosomatic symptoms in young patients with developmental disorder <Original Article>

青年期に初めて精神科を受診する発達障害は多くが高機能であるが，二次障害（併存症）が問題となることが多い。早期に何らかの症状を呈していなかったであろうか。今回われわれは，メンタルヘルス問題をかかえて受診した，発達障害症例73例（男性47例，女性26例）について，過去の心身医学的症状の有無や変遷について調査した。過去の情報が入手できた42例では，59.5％が幼少期に心身症症状を呈していた。心身症症状は多くが青年期になると，抑うつ等の精神症状に変化していた。また，過去に治療を受けた症例の多くは，青年期の適応が良好であった。幼少期の心身症症状などのサインを発見し，早期に介入することで，青年期の二次障害を防ぐことができる可能性が示唆された。Most young patients with developmental disorders who consult psychiatrists for the first time during their adolescence may not have mental weakness, but there is high possibility that they may be suffering from comorbidities. We investigated the presence and transition of past psychosomatic symptoms of 73 patients (47 male and 26 female) with developmental disorders. Past information was available in 42 cases, and 59.5% of them had psychosomatic symptoms in their childhood. The symptoms changed for depressive symptoms in many cases. Many cases treated in the past showed good adaptation during their adolescence. Finding psychosomatic symptoms during childhood and intervening at an early time may prevent secondary psychiatric symptoms in their adolescence

Detailed course of depressive symptoms and risk for developing depression in late adolescents with subthreshold depression: a cohort study

Purpose: Despite its clinical importance, adolescent subthreshold depression remains a largely neglected topic. The aims of this study were to accurately identify the natural course of depressive symptoms and the risk for developing major depressive episode (MDE) in late adolescents with subthreshold depression over 1 year. Patients and methods: One hundred and seventy-two participants <20 years of age (mean age: 18.32 years, standard deviation: 0.50), who did not meet the full criteria for an MDE, were selected from 2, 494 screened freshmen based on the Beck Depression Inventory, 2nd edition (BDI-II). We conducted a cohort study of three groups (low-, middle-, and high-symptom groups) divided based on BDI-II scores, over a 1 year period with the use of bimonthly assessments. Temporal changes of depressive symptoms were analyzed using linear mixed modeling and growth mixture modeling. Results: First, we found that late adolescents with subthreshold depression (high depressive symptoms) were split between the increasing and decreasing depressive symptoms groups, whereas the majority of the less-symptoms group remained stable during 1 year. Second, in comparison with late adolescents with less depressive symptoms, those with subthreshold depression had an elevated risk of later depression. Conclusion: Some late adolescents with subthreshold depression had increased depressive symptoms and developed an MDE during 1 year. Therefore, it is necessary for us to rigorously assess the changes in subthreshold depressive symptoms over time in late adolescents

Inward-oriented Japanese students and international exchange <Original Article>

グローバル人材育成の一環として，日本人大学生の海外留学を促進させるべく多くの留学プログラムが高等教育機関では提供されている。しかし，国内での国際交流も，グローバル人材育成において重要な役割を担っている。本研究では，「内向き志向」と国際交流について検討した。国際交流における問題や利点について検討し，「内向き」と「外向き」な大学生を比較検討した。その結果，国際交流の意思と経験には差がなかった。しかし，「内向き」な大学生は，留学生との文化の違いや留学生とかかわることに対する不安が高く，その一方で，「外向き」な大学生は，国際感覚や就職に役立つ経験を，国際交流を通して得ることができると感じていた。国際交流を促す際，国際交流の良さや注意点について十分に情報提供し，特に「内向き」な大学生の不安を和らげることの重要性が示唆された。Higher education institutions are offering many study abroad programs for Japanese university students for them to build their global talents. However, international exchange programs with international students in Japan are also thought to play an important role in building Japanese students’ global talents. In this study, the relationship between inward-oriented students and international exchange was discussed. The problems and merits of international exchange were examined, and inward-oriented students and outward-oriented students were compared. There were no differences in their willingness or in their experiences of international exchange. However, inward-oriented students felt more anxious about the difference in cultures and about having relationships with international students. On the other hand, outward-oriented students thought that they will be able to build their international sensibility through international exchange and that it will be an experience which will help them with their career. The importance of presenting the students with enough information about the good aspects and cautions of international exchange is emphasized especially to decrease the anxiousness of inward-oriented students

Relationship between developmental disabilities and school avoidance tendencies in university students <Original Article>

本研究は大学生の発達障害の特性と不登校傾向との関連について検討することを目的とした。無記名自記式の質問紙調査を行い，分析対象者は284名であった。クラスタ分析の結果，全ての尺度において困難を頻繁に感じている群の学生は，登校回避傾向が最も高かった。重回帰分析の結果，「不注意」が「登校回避行動」に影響を与え，「不安・抑うつ」「不注意」が「登校回避感情」に影響を与えることが示された。対人関係や心理的問題に限らず，学生の自己管理能力にも注目して関わることが，不登校の学生支援において有効である可能性が示唆された。The purpose of this study was to disclose the relationship between developmental disabilities and school avoidance tendencies in university students. Data of 284 university students who answered questionnaires anonymously were analyzed. As a result of the cluster analysis, students who frequently feel difficulty in all measures had the highest school avoidance tendencies. As a result of the multi-regression analysis, it was indicated that “carelessness” had influence on “attitudes of school avoidance tendency”, and that “anxiety and depression” and “carelessness” had influence on “feelings of school avoidance tendency”. Focusing on the students’ self-management abilities as well as interpersonal relationships and psychological problems is suggested to be effective when supporting students with school avoidance tendencies

Inward-oriented Japanese students and studying abroad <Original Articles>

グローバル人材育成の一環として留学生の派遣が推進されているが,海外留学する日本人学生数は,2004年をピークに減少し続けている。留学を阻害する要因として,留学費用や留学時期以外に,若者の「内向き志向」が問題視されている。そこで,本研究では,「内向き志向」と留学の関係について検討した。「内向き志向」を「内向性」と捉え,留学に関して,内向群と外向群の差について検討した。外向群に比べ,内向群に留学意思はなく,海外での生活や対人関係,語学力不足,留学先の教育レベルの高さなどをより問題視していた。「内向き」な学生の不安を軽減するような留学に関する情報提供により,海外留学は促進されると考えられた。The number of Japanese university students who study abroad has been decreasing since 2004. Other than the cost and time of studying abroad, Japanese students being inward-oriented is said to be influencing the decrease of students studying abroad. In this study, the relationship between inward-oriented students and studying abroad is discussed. Compared to outward-oriented students, inward-oriented students did not want to study abroad. They were anxious about living abroad, relationships abroad, language barrier, and the level of education abroad. It was thought that the number of Japanese students studying abroad would increase by giving inward-oriented students information which will relieve their anxiousness

Enduring effects of a 5-week behavioral activation program for subthreshold depression among late adolescents: an exploratory randomized controlled trial

Background: No significant effect of psychological treatment has been reported from meta-analysis of subthreshold depression patients and control subjects at 1-year follow-up. However, behavioral activation is a simpler and more cost-effective treatment than cognitive behavioral therapy. The primary purpose of this study was to assess by comparison to an assessment-only control group whether the effects of behavioral activation program for depressive symptoms can persist up to 1-year follow-up without the use of antidepressants or other psychotherapy. Patients and methods: Late adolescent students were the population targeted in this study. Participants were allocated randomly to an intervention group (n=62) or a control group (n=56). Treatment consisted of five-weekly 60-minute sessions. Participants underwent a structured interview and completed self-report scales at 1 year post-assessment. Results: Late adolescent students receiving treatment had significantly lower mean Beck Depression Inventory, second edition scores at 1-year follow-up than control group students. The effect size (Hedges’ g) for between-group differences at 1-year follow-up was -0.41. Conclusion: Our behavioral activation program is simple and short. Nevertheless, the results obtained at 1-year follow-up of the control group and late adolescent students receiving treatment indicated a significant difference in their Beck Depression Inventory, second edition scores. Our 5-week behavioral activation program based on behavioral characteristics for subthreshold depression might be promising for subthreshold depression. The sample examined for this study imposed some study limitations