Neural effects of cognitive-behavioural therapy on dysfunctional attitudes in depression

The multi-level outcome study of psychoanalysis for chronically depressed patients with early trauma (MODE): rationale and design of an international multicenter randomized controlled trial

BACKGROUND

Whether and how psychotherapies change brain structure and function is unknown. Its study is of great importance for contemporary psychotherapy, as it may lead to discovery of neurobiological mechanisms that predict and mediate lasting changes in psychotherapy, particularly in severely mentally ill patients, such as those with chronic depression. Previous studies have shown that psychoanalytic psychotherapies produce robust and enduring improvements in not only symptom severity but also personality organization in patients who have chronic depression and early life trauma, especially if therapy is delivered at a high weekly frequency.

METHODS/DESIGN

Patients with chronic major depression and a history of early life trauma will be recruited, assessed, and treated across 3 international sites: Germany, Switzerland, and the United States. They will be randomized to one of two treatment arms: either (1) once weekly psychoanalytic psychotherapies, or (2) 3-4 times weekly psychoanalytic psychotherapies. They will have full clinical characterization as well as undergo MRI scanning at study baseline prior to randomization and again one year later. A group of matched healthy controls will undergo similar assessments and MRI scanning at the same time points to help discern whether study treatments induce brain changes toward or away from normal values. Primary study outcomes will include anatomical MRI, functional MRI, and Diffusion Tensor Imaging measures. Study hypotheses will be tested using the treatment-by-time interaction assessed in multiple general linear models with repeated measures analyses in an intent-to-treat analysis.

DISCUSSION

MODE may allow the identification of brain-based biomarkers that may be more sensitive than traditional behavioral and clinical measures in discriminating, predicting, and mediating treatment response. These findings could help to personalize care for patients who have chronic depression patients and early life trauma, and they will provide new therapeutic targets for both psychological and biological treatments for major depressive illness.

Effects of childhood neglect on regional brain activity and corresponding functional connectivity in major depressive disorder and healthy people: Risk factor or resilience?

BACKGROUND

Childhood neglect is a high risk factor for major depressive disorder (MDD). However, the effects of childhood neglect on regional brain activity and corresponding functional connectivity in MDD patients and healthy populations remains unclear.

METHODS

Regional homogeneity, amplitude of low-frequency fluctuations (ALFF), fractional ALFF, degree centrality, and voxel-mirrored homotopic connectivity were extensively calculated to explore intraregional brain activity in MDD patients with childhood neglect and in healthy populations with childhood neglect. Functional connectivity analysis was then performed using regions showing abnormal brain activity in regional homogeneity/ALFF/fractional ALFF/degree centrality/voxel-mirrored homotopic connectivity analysis as seed. Partial correlation analysis and moderating effect analysis were used to explore the relationship between childhood neglect, abnormal brain activity, and MDD severity.

RESULTS

We found decreased brain function in the inferior parietal lobe and cuneus in MDD patients with childhood neglect. In addition, we detected that childhood neglect was significant associated with abnormal cuneus brain activity in MDD patients and that abnormal cuneus brain activity moderated the relationship between childhood neglect and MDD severity. In contrast, higher brain function was observed in the inferior parietal lobe and cuneus in healthy populations with childhood neglect.

CONCLUSIONS

Our results provide new evidence for the identification of neural biomarkers in MDD patients with childhood neglect. More importantly, we identify brain activity characteristics of resilience in healthy populations with childhood neglect, providing more clues to identify neurobiological markers of resilience to depression after suffering childhood neglect.

Neural Effects of Cognitive Behavioral Therapy in Psychiatric Disorders: A Systematic Review and Activation Likelihood Estimation Meta-Analysis

Background

Cognitive behavioral therapy (CBT) is a first-line psychotherapeutic treatment that has been recommended for psychiatric disorders. Prior neuroimaging studies have provided preliminary evidence suggesting that CBT can have an impact on the activity of brain regions and functional integration between regions. However, the results are far from conclusive. The present article aimed to detect characteristic changes in brain activation following CBT across psychiatric disorders.

Method

Web of Science, Cochrane Library, Scopus, and PubMed databases were searched to identify whole-brain functional neuroimaging studies of CBT through 4 August 2021. To be included in the meta-analysis, studies were required to examine functional activation changes between pre-and post-CBT. The included studies were then divided into subgroups according to different task paradigms. Then, an activation likelihood estimation algorithm (ALE) was performed in the different meta-analyses to identify whether brain regions showed consistent effects. Finally, brain regions identified from the meta-analysis were categorized into eight functional networks according to the spatial correlation values between independent components and the template.

Results

In total, 13 studies met inclusion criteria. Three different meta-analyses were performed separately for total tasks, emotion tasks, and cognition tasks. In the total task ALE meta-analysis, the left precuneus was found to have decreased activation. For the cognition task ALE meta-analysis, left anterior cingulate (ACC) and left middle frontal gyrus (MFG) were found to have decreased activation following CBT. However, the emotion task ALE meta-analysis did not find any specific brain regions showing consistent effects. A review of included studies revealed default mode network (DMN), executive control network (ECN), and salience network (SN) were the most relevant among the eight functional networks.

Conclusion

The results revealed that the altered activation in the prefrontal cortex and precuneus were key regions related to the effects of CBT. Therefore, CBT may modulate the neural circuitry of emotion regulation. This finding provides recommendations for the rapidly developing literature.

Cognitive behavioral therapy may rehabilitate abnormally functional communication pattern among the triple-network in major depressive disorder: A follow-up study

BACKGROUND

Cognitive behavioral therapy (CBT) is an established treatment for Major Depressive Disorder (MDD). MDD is characterized by imbalanced communication patterns among three networks: the central executive network (CEN), the default mode network (DMN) and the salience network (SN). The effect of CBT in restoring communications among these networks in MDD is unknown.

METHODS

Thirty-three patients with MDD and 27 healthy controls (HC) participated in the study. Patients were treated with CBT. Resting-state functional magnetic resonance imaging (rs-fMRI) data were obtained in patients at three stages (T0: before treatment; T1: after 6 weeks CBT; T2: after 28 weeks CBT) and in HC (only T0). Both independent component analysis (ICA) and granger causality analysis (GCA) were used to explore dynamic causal communication patterns among the three networks (CEN, DMN, SN) over a course of CBT treatment.

RESULTS

In the HC group, the SN had an inhibitory causal effect on CEN; the CEN and DMN had an excitatory causal effect on the SN. The SN had an inhibitory causal effect on the CEN and the DMN; only the DMN had an excitatory causal effect on the SN in the MDD patients at the T0 stage. As the CBT treatment went on for MDD patients, the CEN restored excitatory causal effect on the SN, and the SN lost inhibitory effect on the DMN. This result mimicked the one found in the HC group. Four regions, left ventromedial prefrontal cortex (lvmPFC), posterior cingulate gyrus (PCC), right inferior parietal lobule (rIPL) and right insula, were implicated in mediating network communications.

LIMITATIONS

The findings should be considered preliminary given the small sample sizes, and assessed only one stage in HC subjects.

CONCLUSION

CBT may enhance the regulatory function of the SN, and rehabilitate the imbalanced brain network communication mode in the MDD. PCC, lvmPFC and rIPL may all be potential targets of CBT.

Dysfunctional Attitudes Mediate the Relationship Between Childhood Emotional Neglect and Anhedonia in Young Adult Major Depression Patients

BACKGROUND

Childhood traumas are well-established risk factors for major depressive disorder (MDD). However, the relationship between childhood traumas types and MDD symptoms is unclear. The present study tested the hypothesis that childhood traumas affect specific types of anhedonia in depression and the mediating role of dysfunctional attitude.

METHODS

Within this cross-sectional study, 310 young adult patients with MDD completed the PHQ-9, CTQ-SF, DAS, and SHAPS. The statistical analyses used the Mann-Whitney U test, Spearman's rank correlation, and multiple regression analysis. Mediation analyses were tested by the structural equation model (SEM).

RESULTS

Spearman's rank correlation analysis showed positive correlations between the SHAPS, CTQ-SF, and DAS total score (p < 0.05). The EA, EN, PN, and SHAPS scores were positively correlated (p < 0.05). Among the four factors of anhedonia, social interaction and interest/pastimes were positively correlated with EA, EN, and PN (p < 0.05), the sensory experience was positively correlated with EN (p < 0.01), and diet did not correlate with childhood traumas. Stepwise regression analysis showed that dysfunctional attitude and emotional neglect were the main influencing factors of sensory experience (p < 0.001) and social interaction (p < 0.001). Dysfunctional attitude and physical neglect were the main factors influencing interest/pastimes (p < 0.001). SEM analysis found that dysfunctional mediated between childhood traumas and anhedonia.

CONCLUSIONS

The degree of anhedonia was related to dysfunctional attitudes and childhood traumas. The childhood emotional neglect experience was the most important and was related to sensory and social anhedonia. Dysfunctional attitudes played a mediating role between childhood neglect and anhedonia. Early psychotherapy targeting young adult MDD patients with childhood emotional neglect may help decrease symptoms of anhedonia.

Discrepancies between self-rated depression and observed depression severity: The effects of personality and dysfunctional attitudes

BACKGROUND

Patient self-reports and clinician ratings of depression severity can differ substantially. The aim of the current study was to explore factors associated with discrepancies between depressed patients' Patient Health Questionnaire (PHQ-9) self-reports and clinicians' Hamilton Rating Scale for Depression (HAMD-17) ratings.

METHODS

We first computed discrepancy scores defined as the standardized weighted HAMD-17 total score minus the standardized PHQ-9 total score. To assess correlates of inconsistent scores, results of patients with similar standardized scores were removed (i.e., within ½ standard deviation, n = 270). Positive values indicate underreporting (HAMD-17 > PHQ-9), i.e., the underreporting group (n = 200); and negative discrepancy scores indicate overreporting (PHQ-9 > HAMD-17), i.e., the overreporting group (n = 221). We examined the relationship of demographic, dysfunctional attitudes and personality variables to the discrepancies between self and observer rated depression.

RESULTS

There were significant differences in extraversion, psychoticism, neuroticism, dysfunctional attitudes and occupation between the underreporting group and the overreporting group (all p < .05). When controlling for potential confounding variables, being a working professional and having high neuroticism and dysfunctional attitudes were significantly associated with overestimating symptoms of depression (e.g., professional: OR, 2.89; 95% CI, 1.67-5.00; p < .001; high neuroticism: OR, 7.08; 95% CI, 1.47-34.08; p < .001;dysfunctional attitudes: OR, 1.01; 95% CI, 1.00-1.02; p = .030). People with average, or high extraversion tended to underestimate scores (average extraversion: OR, 0.59; 95% CI, 0.37-0.95; high extraversion: OR, 0.48; 95% CI, 0.24-0.98).

CONCLUSIONS

This study is the first to use PHQ-9 and HAMD-17 to explore the discrepancies between self and observer rated depression. Discrepancies occurred between the PHQ-9 score and HAMD-17 score, which were related to neuroticism, extraversion, dysfunctional attitudes and being a working professional. Future research should clarify the relationship between these factors and therapeutic effects of treatments, including adverse outcomes.

[Neuronal effects and biomarkers of antidepressant treatments : Current review from the perspective of neuroimaging]

Depression is one of the most frequent and disabling mental disorders worldwide and is accompanied by a severe impairment in the quality of life. There are numerous imaging studies showing differences in the volume of gray and white brain matter and function between patients suffering from depression and healthy controls. Neuroimaging studies show that pharmacotherapy and electroconvulsive therapy are accompanied by an increase of hippocampal gray matter volume while as a result of psychotherapy activity changes in the anterior cingulate cortex (ACC) have repeatedly been reported. By the identification of neuroanatomical markers, baseline volumes of the ACC have also been shown to be associated with therapy response to all treatments. The identification of such neuronal biomarkers in combination with machine learning techniques provide a promising step towards a neurobiologically based application for the prediction of treatment response.

Alterations in patients with major depressive disorder before and after electroconvulsive therapy measured by fractional amplitude of low-frequency fluctuations (fALFF)

BACKGROUND

Electroconvulsive therapy (ECT) is an important treatment option for patients with major depressive disorder (MDD). However, the mechanisms of ECT in MDD are still unclear.

METHODS

Twenty-four patients with severe MDD and 14 healthy controls were enrolled in this study. Eight ECT sessions were conducted for MDD patients using brief-pulse square-wave signal at bitemporal locations. To investigate the regional cerebral blood flow in MDD patients before and after ECT treatments by resting-state functional magnetic resonance imaging (rs-fMRI), the patients were scanned twice (before the first ECT and after the eighth ECT) for data acquisition. Afterward, we adopted fractional amplitude of low-frequency fluctuations (fALFF) to assess the alterations of regional brain activity.

RESULTS

Compared with healthy controls, the fALFF in the cerebellum lobe, parahippocampal gyrus, fusiform gyrus, anterior cingulate gyrus, and thalamus in MDD patients before ECT (pre-ECT) was significantly increased. In another comparison, the fALFF in the cerebellum anterior lobe, fusiform gyrus, insula, parahippocampal gyrus, middle frontal gyrus, and inferior frontal gyrus in pre-ECT patients was significantly greater than the post-ECT fALFF.

LIMITATIONS

Only two rs-fMRI scans were conducted at predefined times: before the first and after the eighth ECT treatment. More scans during the ECT sessions would yield more information. In addition, the sample size in this study was limited. The number of control subjects was relatively small. A larger number of subjects would produce more robust findings.

CONCLUSIONS

The fALFF of both healthy controls and post-ECT patients in cerebellum anterior lobe, fusiform gyrus, and parahippocampal gyrus is significantly lower than the fALFF of pre-ECT patients. This finding demonstrates that ECT treatment is effective on these brain areas in MDD patients.

A novel task for examining the neural basis of Theory of Mind deficits in bipolar disorder

Deficits in theory of mind (ToM) processing have been observed in people with bipolar disorder (BD), but the neural basis of these deficits remains unclear. Here, we studied the relations between neural activation, dysfunctional beliefs and behavioral responses in people with BD during a second-order ToM task. Twenty-five patients and 25 healthy-control participants (HC) underwent functional magnetic resonance imaging (fMRI) while performing a novel ToM task. The Dysfunctional Attitudes scale (DAS) and the Brief Hypomanic Attitudes and Positive Predictions Inventory (BHAPPI) were used to assess dysfunctional beliefs. Significant differences in neural activation were observed between HC and BD patients in regions associated with ToM processing: medial frontal, cingulate, anterior cingulate and superior temporal gyri. Correlations between DAS scores and neural activity in medial frontal and cingulate gyri were observed for HC only. Increased activation in brain regions associated with ToM processing in patients compared to HC provides further evidence of disruption in networks controlling social-cognitive processes. Whether this results from compensatory responses to maintain appropriate behavior is unknown.

Meta-analyses of the neural mechanisms and predictors of response to psychotherapy in depression and anxiety

Understanding the neural mechanisms underlying psychological therapy could aid understanding of recovery processes and help target treatments. The dual-process model hypothesises that psychological therapy is associated with increased emotional-regulation in prefrontal brain regions and decreased implicit emotional-reactivity in limbic regions; however, research has yielded inconsistent findings. Meta-analyses of brain activity changes accompanying psychological therapy (22 studies, n = 352) and neural predictors of symptomatic improvement (11 studies, n = 293) in depression and anxiety were conducted using seed-based d mapping. Both resting-state and task-based studies were included, and analysed together and separately. The most robust findings were significant decreases in anterior cingulate/paracingulate gyrus, inferior frontal gyrus and insula activation after therapy. Cuneus activation was predictive of subsequent symptom change. The results are in agreement with neural models of improved emotional-reactivity following therapy as evidenced by decreased activity within the anterior cingulate and insula. We propose compensatory as well as corrective neural mechanisms of action underlie therapeutic efficacy, and suggest the dual-process model may be too simplistic to account fully for treatment mechanisms. More research on predictors of psychotherapeutic response is required to provide reliable predictors of response.

A systematic review and meta-analysis of the neural correlates of psychological therapies in major depression

Longitudinal neuroimaging studies in major depression have revealed cortico-limbic abnormalities which are modulated by treatment. We performed a systematic review and meta-analysis of psychotherapy treatment studies measuring neural function and metabolism using fMRI, PET, SPECT and MRS. Seventeen studies were included in the systematic review, total of 200 major depression participants (mean age 37.6 years), all medication free, and 116 healthy controls (mean age 36.4 years). Neuroimaging assessments were performed prior to initiation of treatment and following course of treatment. Treatment durations were: 16-30 weeks for CBT, 11 weeks for behavioral activation therapy, and up to 15 months for psychodynamic psychotherapy. The meta-analysis consisted of studies in which both groups had same serial scans and comparable tasks; total of 5 studies with visual presentation tasks of emotional stimuli: 55 patients (mean age: 38.7 years) and 55 healthy controls (mean age: 36.3 years). The meta-analysis revealed a significant group by time effect in left rostral anterior cingulate, in which patients showed increased activity following psychotherapy while healthy controls showed a decrease at follow up. Longitudinal treatment effects revealed reduced left precentral cortical activity in major depression. Findings could be indicative of improvements in emotion responsivity that may be achieved following psychotherapy.

Disentangling the Neural Basis of Cognitive Behavioral Therapy in Psychiatric Disorders: A Focus on Depression

Background: Major depressive disorder (MDD) stands among the most frequent psychiatric disorders. Cognitive behavioral therapy (CBT) has been shown to be effective for treating depression, yet its neural mechanisms of action are not well elucidated. The objective of this work is to assess the available neuroimaging studies exploring CBT’s effects in adult patients with MDD. Methods: Computerized databases were consulted till April 2018 and a research was conducted according to PRISMA guidelines in order to identify original research articles published at any time in English and French languages on this topic. Results: Seventeen studies were identified. Only one study was randomized comparing CBT to pharmacological interventions, and none included an effective control. Following CBT, changes occurred in cerebral areas that are part of the fronto-limbic system, namely the cingulate cortex, prefrontal cortex and amygdala-hippocampal complex. However, the pattern of activation and connectivity in these areas varied across the studies. Conclusion: A considerable heterogeneity exists with regard to study design, adapted CBT type and intensity, and employed neuroimaging paradigms, all of which may partly explain the difference in studies’ outcomes. The lack of randomization and effective controls in most of them makes it difficult to draw formal conclusion whether the observed effects are CBT mediated or due to spontaneous recovery. Despite the observed inconsistencies and dearth of data, CBT appears to exert its anti-depressant effects mainly by modulating the function of affective and cognitive networks devoted to emotions generation and control, respectively. This concept remains to be validated in large scale randomized controlled trials.

Epigenetic and Neural Circuitry Landscape of Psychotherapeutic Interventions

The science behind psychotherapy has garnered considerable interest, as objective measures are being developed to map the patient's subjective change over the course of treatment. Prenatal and early life influences have a lasting impact on how genes are expressed and the manner in which neural circuits are consolidated. Transgenerationally transmitted epigenetic markers as well as templates of enhanced thought flexibility versus evasion can be passed down from parent to child. This influences gene expression/repression (impacting neuroplasticity) and kindling of neurocircuitry which can perpetuate maladaptive cognitive processing seen in a number of psychiatric conditions. Importantly, genetic factors and the compounding effects of early life adversity do not inexorably lead to certain fated outcomes. The concepts of vulnerability and resilience are becoming more integrated into the framework of "differential susceptibility," speaking to how corrective environmental factors may promote epigenetic change and reconfigure neural templates, allowing for symptomatic improvement. Psychotherapy is one such factor, and this review will focus on our current knowledge of its epigenetic and neurocircuitry impact.

A quick behavioral dichotic word test is prognostic for clinical response to cognitive therapy for depression: A replication study

There are no commonly used clinical indicators of whether an individual will benefit from cognitive therapy (CT) for depression. A prior study found right ear (left hemisphere) advantage for perceiving dichotic words predicted CT response. This study replicates this finding at a different research center in clinical trials that included clinically representative samples and community therapists. Right-handed individuals with unipolar major depressive disorder who subsequently received 12-14 weeks of CT at the University of Pittsburgh were tested on dichotic fused words and complex tones tests. Responders to CT showed twice the mean right ear advantage in dichotic fused words performance than non-responders. Patients with a right ear advantage greater than the mean for healthy controls had an 81% response rate to CT, whereas those with performance lower than the mean for controls had a 46% response rate. Individuals with a right ear advantage, indicative of strong left hemisphere language dominance, may be better at utilizing cognitive processes and left frontotemporal cortical regions critical for success of CT for depression. Findings at two clinical research centers suggest that verbal dichotic listening may be a clinically disseminative brief, inexpensive and easily automated test prognostic for response to CT across diverse clinical settings.

Adolescent Major Depressive Disorder: Neuroimaging Evidence of Sex Difference during an Affective Go/No-Go Task

Compared to female major depressive disorder (MDD), male MDD often receives less attention. However, research is warranted since there are significant sex differences in the clinical presentation of MDD and a higher rate of suicide in depressed men. To the best of our knowledge, this is the first functional magnetic resonance imaging (fMRI) study with a large sample addressing putative sex differences in MDD during adolescence, a period when one of the most robust findings in psychiatric epidemiology emerges; that females are twice as likely to suffer from MDD than males. Twenty-four depressed and 10 healthy male adolescents, together with 82 depressed and 24 healthy female adolescents, aged 11-18 years, undertook an affective go/no-go task during fMRI acquisition. In response to sad relative to neutral distractors, significant sex differences (in the supramarginal gyrus) and group-by-sex interactions (in the supramarginal gyrus and the posterior cingulate cortex) were found. Furthermore, in contrast to the healthy male adolescents, depressed male adolescents showed decreased activation in the cerebellum with a significant group-by-age interaction in connectivity. Future research may consider altered developmental trajectories and the possible implications of sex-specific treatment and prevention strategies for MDD.

Modulation of the Default Mode Network in First-Episode, Drug-Naïve Major Depressive Disorder via Acupuncture at Baihui (GV20) Acupoint

BACKGROUND

Previous neuroimaging studies have revealed that acupuncture modulates the default mode network (DMN) in healthy subjects and patients with certain disorder. However, few studies have been performed to investigate whether or not acupuncture might modulate the DMN in patients with major depressive disorder (MDD). Thereby, the aim of the present study was to assess alterations of the DMN induced by acupuncture stimulation in patients with first-episode, drug-naïve MDD.

MATERIALS AND METHODS

Twenty nine patients with first-episode, drug-naïve MDD and 29 healthy subjects were enrolled in this study. All the healthy subjects underwent 6-min resting-state functional magnetic resonance imaging (R-fMRI) scan. While patients underwent acupuncture stimulation for 20-min electro-acupuncture stimulation (EAS) at Baihui acupoint (GV20) and two 6-min R-fMRI scans before and after EAS. Based on the precuneus/posterior cingulate cortex (PC/PCC) as the seed region, functional connectivity (FC) method was adopted to examine abnormal DMN in patients by comparing with healthy subjects and to evaluate the influence of EAS on intrinsic connectivity within the DMN in patients with MDD.

RESULTS

Compared to healthy subjects, MDD patients had abnormal DMN. Moreover, results showed that EAS at GV20 induced increased FC between the PC/PCC and bilateral anterior cingulate cortex (ACC), and decreased FC between the PC/PCC and left middle prefrontal cortex, left angualr gyrus and bilateral hippocampus/parahippocampus (HIPP/paraHIPP) in patients with MDD, which were the main brain regions showing significant differences between the patients and healthy subjects.

CONCLUSION

Our findings provide imaging evidence to support that GV20-related acupuncture stimulation may modulate the DMN in patients with first-episode, drug-naïve MDD. This study may partly interpret the neural mechanisms of acupuncture at GV20 which is used to treat patients with MDD in clinical.

Cognitive behavioural therapy for depression: systematic review of imaging studies

OBJECTIVE

Although cognitive behavioural therapy (CBT) has been shown to be an effective treatment for depression, the biological mechanisms underpinning it are less clear. This review examines if it is associated with changes identifiable with current brain imaging technologies.

METHODS

To better understand the mechanisms by which CBT exerts its effects, we undertook a systematic review of studies examining brain imaging changes associated with CBT treatment of depression.

RESULTS

Ten studies were identified, five applying functional magnetic resonance imaging, three positron emission tomography, one single photon emission computer tomography, and one magnetic resonance spectroscopy. No studies used structural MRI. Eight studies included a comparator group; in only one of these studies was there randomised allocation to another treatment. CBT-associated changes were most commonly observed in the anterior cingulate cortex (ACC), posterior cingulate, ventromedial prefrontal cortex/orbitofrontal cortex (VMPFC/OFC) and amygdala/hippocampus.

DISCUSSION

The evidence, such as it is, suggests resting state activity in the dorsal ACC is decreased by CBT. It has previously been suggested that treatment with CBT may result in increased efficiency of a putative 'dorsal cognitive circuit', important in cognitive control and effortful regulation of emotion. It is speculated this results in an increased capacity for 'top-down' emotion regulation, which is employed when skills taught in CBT are engaged. Though changes in activity of the dorsal ACC could be seen as in-keeping with this model, the data are currently insufficient to make definitive statements about how CBT exerts its effects. Data do support the contention that CBT is associated with biological brain changes detectable with current imaging technologies.

Functional neuroimaging of psychotherapeutic processes in anxiety and depression: from mechanisms to predictions

PURPOSE OF REVIEW

The review provides an update of functional neuroimaging studies that identify neural processes underlying psychotherapy and predict outcomes following psychotherapeutic treatment in anxiety and depressive disorders. Following current developments in this field, studies were classified as 'mechanistic' or 'predictor' studies (i.e., informing neurobiological models about putative mechanisms versus aiming to provide predictive information).

RECENT FINDINGS

Mechanistic evidence points toward a dual-process model of psychotherapy in anxiety disorders with abnormally increased limbic activation being decreased, while prefrontal activity is increased. Partly overlapping findings are reported for depression, albeit with a stronger focus on prefrontal activation following treatment. No studies directly comparing neural pathways of psychotherapy between anxiety and depression were detected. Consensus is accumulating for an overarching role of the anterior cingulate cortex in modulating treatment response across disorders. When aiming to quantify clinical utility, the need for single-subject predictions is increasingly recognized and predictions based on machine learning approaches show high translational potential.

SUMMARY

Present findings encourage the search for predictors providing clinically meaningful information for single patients. However, independent validation as a crucial prerequisite for clinical use is still needed. Identifying nonresponders a priori creates the need for alternative treatment options that can be developed based on an improved understanding of those neural mechanisms underlying effective interventions.