Neurobiological and clinical effect of metacognitive interpersonal therapy vs structured clinical model: study protocol for a randomized controlled trial

Effect of metacognitive interpersonal therapy on brain structural connectivity in borderline personality disorder: Results from the CLIMAMITHE randomized clinical trial

BACKGROUND

Recently, we showed that Metacognitive Interpersonal Therapy (MIT) is effective in improving clinical symptoms in borderline personality disorder (BPD). Here, we investigated whether the effect of MIT on clinical features is associated to microstructural changes in brain circuits supporting core BPD symptoms.

METHODS

Forty-seven BPD were randomized to MIT or structured clinical management, and underwent a clinical assessment and diffusion-weighted imaging before and after the intervention. Fractional anisotropy (FA), mean, radial, and axial diffusivities maps were computed using FSL toolbox. Microstructural changes were assessed (i) voxel-wise, with tract based spatial statistics (TBSS) and (ii) ROI-wise, in the triple network system (default mode, salience, and executive control networks). The effect of MIT on brain microstructure was assessed with paired tests using FSL PALM (voxel-wise), Linear Mixed-Effect Models or Generalized Linear Mixed Models (ROI-wise). Associations between microstructural and clinical changes were explored with linear regression (voxel-wise) and correlations (ROI-wise).

RESULTS

The voxel-wise analysis showed that MIT was associated with increased FA in the bilateral thalamic radiation and left associative tracts (p < .050, family-wise error rate corrected). At network system level, MIT increased FA and both interventions reduced AD in the executive control network (p = .05, uncorrected).

LIMITATIONS

The DTI metrics can't clarify the nature of axonal changes.

CONCLUSIONS

Our results indicate that MIT modulates brain structural connectivity in circuits related to associative and executive control functions. These microstructural changes may denote activity-dependent plasticity, possibly representing a neurobiological mechanism underlying MIT effects.

TRIAL REGISTRATION

ClinicalTrials.govNCT02370316 (https://clinicaltrials.gov/study/NCT02370316).

Improving treatment outcomes for borderline personality disorder: what can we learn from biomarker studies of psychotherapy?

PURPOSE OF REVIEW

Borderline personality disorder (BPD) is a severe and common psychiatric disorder and though evidence-based psychotherapies are effective, rates of treatment nonresponse are as high as 50%. Treatment studies may benefit from interdisciplinary approaches from neuroscience and genetics research that could generate novel insights into treatment mechanisms and tailoring interventions to the individual.

RECENT FINDINGS

We provide a timely update to the small but growing body of literature investigating neurobiological and epigenetic changes and using biomarkers to predict outcomes from evidence-based psychotherapies for BPD. Using a rapid review methodology, we identified eight new studies, updating our earlier 2018 systematic review. Across all studies, neuroimaging ( n  = 18) and genetics studies ( n  = 4) provide data from 735 participants diagnosed with BPD (mean sample size across studies = 33.4, range 2-115).

SUMMARY

We report further evidence for psychotherapy-related alterations of neural activation and connectivity in regions and networks relating to executive control, emotion regulation, and self/interpersonal functioning in BPD. Emerging evidence also shows epigenetic changes following treatment. Future large-scale multisite studies may help to delineate multilevel treatment targets to inform intervention design, selection, and monitoring for the individual patient via integration of knowledge generated through clinical, neuroscience, and genetics research.

Aberrant Structural Connectivity of the Triple Network System in Borderline Personality Disorder Is Associated with Behavioral Dysregulation

Background: Core symptoms of Borderline Personality Disorder (BPD) are associated to aberrant connectivity of the triple network system (salience network [SN], default mode network [DMN], executive control network [ECN]). While functional abnormalities are widely reported, structural connectivity (SC) and anatomical changes have not yet been investigated. Here, we explored the triple network’s SC, structure, and its association with BPD clinical features. Methods: A total of 60 BPD and 26 healthy controls (HC) underwent a multidomain neuropsychological and multimodal MRI (diffusion- and T1-weighted imaging) assessment. Metrics (fractional anisotropy [FA], mean diffusivity [MD], cortical thickness) were extracted from SN, DMN, ECN (triple network), and visual network (control network) using established atlases. Multivariate general linear models were conducted to assess group differences in metrics and associations with clinical features. Results: Patients showed increased MD in the anterior SN, dorsal DMN, and right ECN compared to HC. Diffusivity increases were more pronounced in patients with higher behavioral dysregulation, i.e., suicidal attempting, self-harm, and aggressiveness. No differences were detected in network structure. Conclusions: These results indicate that the triple network system is impaired in BPD at the microstructural level. The preferential involvement of anterior and right-lateralized subsystems and their clinical association suggests that these abnormalities could contribute to behavioral dysregulation.