Satoshi Yokoyama

The relationship between positive and negative automatic thought and activity in the prefrontal and temporal cortices: A multi-channel near-infrared spectroscopy (NIRS) study

BACKGROUND Recently, neurobiological studies of the cognitive model of depression have become vastly more important, and a growing number of such studies are being reported. However, the relationship between the proportion of positive and negative automatic thought and activity in the prefrontal and temporal cortices has not yet been explored. We examined the relationship between brain activity and the proportion of positive and negative automatic thought in patients with major depressive disorder (MDD), using multi-channel near-infrared spectroscopy (NIRS). METHODS We recruited 75 individuals with MDD (36 females; mean age=39.23 ± 12.49). They completed the Hamilton Rating Scale for Depression, Automatic Thoughts Questionnaire-Revised, Japanese version of the National Adult Reading Test, and the State-Trait Anxiety Inventory. Brain activation was measured by 52-channel NIRS. RESULTS We found that activation in the vicinity of the right superior temporal gyrus is related to a deviation to negative of the proportion of positive and negative thoughts in individuals with MDD. Left dorsolateral prefrontal cortex activity was higher in the group with comparatively frequent positive thought. LIMITATIONS Our participants were patients taking antidepressant medication, which is known to influence brain activity. Second, the poor spatial resolution of NIRS increases the difficulty of identifying the measurement position. CONCLUSIONS We found that activation of the prefrontal and temporal cortices is related to the proportion of automatic thoughts in the cognitive model of depression.

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.

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.

The neural correlates of the metacognitive function of other perspective: a multiple regression analysis study

Perspective taking is defined as the social cognitive function of imagining the world or imagining oneself from another’s viewpoint. Previously, we reported that behavioral activation increased the dorsal medial prefrontal cortex (dmPFC) activation during other perspective self-referential processing for positive words in subthreshold depression, but did not report whether metacognitive function was related to the dmPFC activation. Therefore, we sought to test the relationship between the dmPFC activation during other perspective self-referential processing for positive words and an individual’s metacognitive evaluation of other perspective. Thirty-four healthy individuals underwent functional MRI scans during a referential task with two viewpoints (self/other) and two emotional valences (positive/negative). Neural activation during other perspective self-referential processing for positive words was correlated with the metacognitive function of participants measured by the Interpersonal Reactivity Index (IRI). We found a positive correlation between the score in perspective taking of the IRI and activation in the dmPFC during other perspective self-referential processing for positive words. The present findings showed that self-report questionnaires assessing participants’ metacognitive evaluation of other perspective were correlated with dmPFC activation during positive metacognition of other perspective task. However, we did not conduct a behavioral activation intervention in the present study. The present students were healthy. The IRI is a subjective measure of multidimensional trait empathy. It is necessary to develop an objective measurement for the metacognitive function of other perspective in the near future.

Effects of behavioral activation program without psychotropic medication treatment for depression in late adolescence: case report

Background A Japanese study revealed that 20.7% of first-year undergraduate students had a major depressive episode during the previous 12 months: first-year undergraduate students with depression need early support. Reportedly, antidepressant medication use during adolescence is associated with modestly increased risk of suicidality. This case study of a late-adolescent woman with depression illustrates the effects of behavioral activation without psychotropic medication. Case presentation A first-year undergraduate student was diagnosed as having major depressive disorder. From earlier studies, we developed a behavioral activation program for late-adolescent people with major depressive disorder. Behavioral activation administered in 10 weekly 60-minute sessions decreased depressive symptoms, avoidant behaviors, and rumination. Moreover, the Beck Depression Inventory, second version score was 1 at 1-year follow-up. Conclusion Results of this case study show that behavioral activation is effective without psychotropic medication. Future studies of large samples must be conducted to assess the effectiveness of behavioral activation without psychotropic medication for depression in late adolescence.

Effects of behavioral activation on default mode network connectivity in subthreshold depression: A preliminary resting-state fMRI study

BACKGROUND Subthreshold depression is a risk factor for major depressive disorder, and it is known to have a negative impact on quality of life (QOL). Although behavioral activation, which is one type of cognitive behavioral therapy, is an effective psychological intervention for subthreshold depression, neural mechanisms of behavioral activation are unclear. Enhanced functional connectivity between default mode network (DMN) and the other regions has been demonstrated in participants with subthreshold depression. The purpose of this study was to examine the effects of behavioral activation on DMN abnormalities by using resting-state functional MRI (rs-fMRI). METHODS Participants with subthreshold depression (N =40) were randomly assigned to either an intervention group or a non-intervention group. They were scanned using rs-fMRI before and after the intervention. Independent component analysis indicated three subnetworks of the DMN. RESULTS Analyzing intervention effects on functional connectivity of each subnetwork indicated that connectivity of the anterior DMN subnetwork with the dorsal anterior cingulate was reduced after the intervention. Moreover, this reduction was correlated with an increase in health-related QOL. LIMITATIONS We did not compare the findings with healthy participants. Further research should be conducted by including healthy controls to verify the results of this study. CONCLUSIONS Mechanisms of behavioral activation might be related to enhanced ability to independently use the dACC and the DMN, which increases an attention control to positive external stimuli. This is the first study to investigate neural mechanisms of behavioral activation using rs-fMRI.

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.

Regional brain functions in the resting state indicative of potential differences between depression and chronic pain.

Complex relationships between depression and chronic pain have been reported in previous studies. However, only a few neuroimaging studies have investigated similarities and differences in neural systems underlying them. We examined the brain functions in the resting state of 43 patients with depression, 41 patients with chronic pain (somatoform pain disorder) and 41 healthy controls, by using regional homogeneity (ReHo) and functional connectivity analysis. Depressive symptoms were assessed by using the Beck Depression Inventory-Second Edition (BDI-II). ReHo values for the dorsolateral prefrontal cortex (DLPFC) significantly decreased for chronic pain patients, and functional connectivity between the DLPFC and thalamus decreased only for these patients. These findings are indicative of distinct brain functions related to depression and chronic pain. Understanding these differences would further elucidate the pathophysiology of these conditions.

Laparoscopic-assisted Resection for Jejunal Stenosis Following Extensive Portomesenteric Venous Thrombosis

Introduction: Portomesenteric venous thrombosis (PMVT) is a rare and often fatal disease that is difficult to diagnose. The symptoms are nonspecific, and diagnosis and initial treatment tend to be delayed. The initial treatment strategy for PMVT has recently tended toward the use of conservative methods before surgical intervention, and most patients can be successfully treated in this way. In rare cases, however, bowel strictures may develop, owing to chronic ischemia. Case Description: We present a case of elective laparoscopy-assisted small-bowel resection of ischemic jejunal stenosis following extensive portal, mesenteric, and splenic vein thrombosis. Discussion: Laparoscopy is indicated for this condition because of the possible need for repeated operations and extensive intraoperative exploration. However, laparoscopy with pneumoperitoneum can be a risk factor for recurrent PMVT, indicating the need to develop methods to shorten the operation time.