Koki Takagaki

Behavioral activation can normalize neural hypoactivation in subthreshold depression during a monetary incentive delay task.

BACKGROUND Late adolescents are under increased risk of developing depressive symptoms. Behavioral activation is an effective treatment for subthreshold depression, which can prevent the development of subthreshold depression into a major depressive disorder. However, the neural mechanisms underlying the efficacy of behavioral activation have not been clearly understood. We investigated neural responses during reward processing by individuals with subthreshold depression to clarify the neural mechanisms of behavioral activation. METHODS Late adolescent university students with subthreshold depression (n=15, age 18-19 years) as indicated by a high score on the Becks Depression Inventory-ll (BDI-ll) and 15 age-matched controls with a low BDI-ll score participated in functional magnetic resonance imaging scanning conducted during a monetary incentive delay task on two occasions. The Individuals in the subthreshold depression group received five, weekly behavioral activation sessions between the two scanning sessions. Moreover, they did not receive any medication until the study was completed. RESULTS Behavioral activation significantly reduced depressive symptoms. Moreover, compared to the changes in brain functions in the control group, the behavioral activation group showed functional changes during loss anticipation in brain structures that mediates cognitive and emotional regulation, including the left ventrolateral prefrontal cortex and angular gyrus. LIMITATIONS Replication of the study with a larger sample size is required to increase the generalizability of these results. CONCLUSIONS Behavioral activation results in improved functioning of the fronto-parietal region during loss anticipation. These results increase our understanding of the mechanisms underlying specific psychotherapies.

Direct and indirect influences of childhood abuse on depression symptoms in patients with major depressive disorder

BackgroundIt is known that the onset, progression, and prognosis of major depressive disorder are affected by interactions between a number of factors. This study investigated how childhood abuse, personality, and stress of life events were associated with symptoms of depression in depressed people.MethodsPatients with major depressive disorder (N = 113, 58 women and 55 men) completed the Beck Depression Inventory-II (BDI-II), the Neuroticism Extroversion Openness Five Factor Inventory (NEO-FFI), the Child Abuse and Trauma Scale (CATS), and the Life Experiences Survey (LES), which are self-report scales. Results were analyzed with correlation analysis and structural equation modeling (SEM), by using SPSS AMOS 21.0.ResultsChildhood abuse directly predicted the severity of depression and indirectly predicted the severity of depression through the mediation of personality. Negative life change score of the LES was affected by childhood abuse, however it did not predict the severity of depression.ConclusionsThis study is the first to report a relationship between childhood abuse, personality, adulthood life stresses and the severity of depression in depressed patients. Childhood abuse directly and indirectly predicted the severity of depression. These results suggest the need for clinicians to be receptive to the possibility of childhood abuse in patients suffering from depression.SEM is a procedure used for hypothesis modeling and not for causal modeling. Therefore, the possibility of developing more appropriate models that include other variables cannot be excluded.

fMRI study of social anxiety during social ostracism with and without emotional support.

Social anxiety is characterized by an excessive fear of being embarrassed in social interactions or social performance situations. Emotional support can help to decrease or diminish social distress. Such support may play an important role at different points of social interaction. However, it is unclear how the beneficial effects of social support are represented in the brains of socially anxious individuals. To explore this, we used the same paradigm previously used to examine the effects of emotional support on social pain caused by exclusion. Undergraduates (n = 46) showing a wide range of social anxiety scores underwent functional magnetic resonance imaging (fMRI) while participating in a Cyberball game. Participants were initially included and later excluded from the game. In the latter half of the session in which participants were excluded, they were provided with supportive messages. In line with our previous work, we found that social exclusion led to increased anterior cingulate cortex (ACC) activity, whereas emotional support led to increased left dorsolateral prefrontal cortex (DLPFC) activity. Despite validation of the paradigm, social anxiety was not associated with increased ACC activity during social exclusion, or during perceived emotional support. Instead, fear of negative evaluation as assessed by the Brief Fear of Negative Evaluation (BFNE) scale showed positive associations with left DLPFC activation while receiving emotional support, compared to while being socially excluded. The more socially anxious an individual was, the greater was the left DLPFC activity increased during receipt of messages. This suggests that highly socially anxious people still have the ability to perceive social support, but that they are nevertheless susceptible to negative evaluation by others.

Effects of behavioural activation on the neural basis of other perspective self-referential processing in subthreshold depression: a functional magnetic resonance imaging study

Background It has been demonstrated that negatively distorted self-referential processing, in which individuals evaluate ones own self, is a pathogenic mechanism in subthreshold depression that has a considerable impact on the quality of life and carries an elevated risk of developing major depression. Behavioural activation (BA) is an effective intervention for depression, including subthreshold depression. However, brain mechanisms underlying BA are not fully understood. We sought to examine the effect of BA on neural activation during other perspective self-referential processing in subthreshold depression. Method A total of 56 subjects underwent functional magnetic resonance imaging scans during a self-referential task with two viewpoints (self/other) and two emotional valences (positive/negative) on two occasions. Between scans, while the intervention group (n = 27) received BA therapy, the control group (n = 29) did not. Results The intervention group showed improvement in depressive symptoms, increased activation in the dorsal medial prefrontal cortex (dmPFC), and increased reaction times during other perspective self-referential processing for positive words after the intervention. Also, there was a positive correlation between increased activation in the dmPFC and improvement of depressive symptoms. Additionally, there was a positive correlation between improvement of depressive symptoms and increased reaction times. Conclusions BA increased dmPFC activation during other perspective self-referential processing with improvement of depressive symptoms and increased reaction times which were associated with improvement of self-monitoring function. Our results suggest that BA improved depressive symptoms and objective monitoring function for subthreshold depression.

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.

Behavioral characteristics of subthreshold depression.

BACKGROUND This study examines differences in behavioral characteristics among individuals who are not depressed and individuals with subthreshold depression, and depression. METHODS We conducted structured interviews with 111 undergraduate students, who also completed self-report scales. The participants were divided into a non-depression group, a subthreshold depression group, and a depression group based on results of the structured interview and the BDI-II. RESULTS There were significant differences in avoidance between depression group and other two groups. Also, for the environmental rewards, there were significant difference between the non-depressed group and the other two groups. LIMITATIONS The sample of depressed participants was small. The overall sample consisted only undergraduate students. CONCLUSIONS This study reported that there are different behavioral characteristics among non-depression, subthreshold depression, and depression groups. Whereas depression group is characterized by high frequency of avoidance and low environmental rewards, subthreshold depression group is characterized by only low environmental rewards.

Preliminary Assessment of the Behavioral Activation Model in Japanese Undergraduate Students

Many studies have reported that behavioral activation is an effective intervention for depression. The behavioral activation model is based on several formulations. For example, depressive mood leads to avoidant behaviors, avoidance negatively affects social contacts, decreased socialization lessens opportunities for positive reinforcement, and a decrease in positive reinforcement results in more depressive mood. The purpose of this study was to examine relationships among avoidant behavior, social contact, frequency of positive reinforcement, and depressive mood by using structural equation modeling to assess support for aspects of this behavioral activation model. Participants were 630 Japanese undergraduate students and vocational school students. Results provided preliminary support for the model. Treating both avoidance and activating behavior might contribute to decreased impairment.

Mechanisms of behavioral activation for late adolescents: Positive reinforcement mediate the relationship between activation and depressive symptoms from pre-treatment to post-treatment

BACKGROUND It is suggested that there is some support for notion that frequency of activity can lead to improved mood in behavioral activation, but this research is relatively imprecise. We investigated whether positive reinforcement mediates the relationship between activation and alleviation of depressive symptoms METHODS Late adolescents with sub-threshold depressive symptoms participated in the study. We conducted an intervention using behavioral activation with the participants. Then, pre-and post-treatment results of behavioral activation were compared. We used mediation analysis using the bootstrapping method to examine whether changes in reinforcement mediated the relationship between changes in activation and improvements in depressive symptoms. RESULTS Participants improved significantly at the post-intervention assessment, compared to the baseline assessment. Results of mediation analysis indicated that reinforcement significantly mediated the relationship between activation and depressive symptoms, whereas activation alone had no a direct effect on depressive symptoms. LIMITATIONS Further studies with more diverse samples of participants are required in order to generalize the results of this study to more diverse populations. CONCLUSIONS The study provides the first full mediational test of behavioral activation model including both measures of activation and positive reinforcement, and we found support for behavioral activations presumed mechanism of action that contact with positive reinforcement mediates the relation between activity and depression.

Effectiveness of group cognitive behavioral therapy for somatoform pain disorder patients in Japan: A preliminary non-case-control study.

Somatoform pain disorder is associated with psychosocial dysfunction, and psychotherapies, such as cognitive behavioral therapy (CBT), are thought to provide useful interventions to address such dysfunction as well as the pain itself. However, little is known about whether CBT for somatoform pain disorder is effective, including the long‐term course of the illness, in non‐Western populations. We therefore tailored such a program based on an existing CBT protocol and examined its effectiveness in Japan.

Do Individuals with Alcohol Dependence Show Higher Unfairness Sensitivity? The Relationship Between Impulsivity and Unfairness Sensitivity in Alcohol-Dependent Adults.

BACKGROUND Alcohol-dependent patients are known to be generally more unfairness sensitive. The ultimatum game (UG) is an experimental task designed to provoke feelings of perceived unfairness. A previous study using the UG has reported more unfairness sensitivity in patients with alcohol dependence than in a nondependent control group; it has been speculated that this increased sensitivity might be due to a difficulty in impulse control. However, the mechanism of this relationship has not been clarified. Therefore, the relationship between unfairness sensitivity in interpersonal relationships and impulsivity was investigated using UG and delay discounting (DD) paradigms. METHODS Subjects were 32 individuals with alcohol dependency and 36 healthy control individuals; both groups performed UG and DD tasks. RESULTS Participants with alcohol dependence rejected monetary offers deemed unfair at a significantly higher rate than did control participants. Moreover, the proportion of accepting unfairness was negatively correlated with impulsivity in patients with alcohol dependence. CONCLUSIONS Perceived unfairness is related to impulsivity in patients with alcohol dependence. These results provide insights concerning the psychopathology of alcohol dependence.