Boosting the Theory of Mind Network: Specific Psychotherapy Increases Neural Correlates of Affective Theory of Mind in Euthymic Bipolar Disorder.

Objectives: In BD, impaired affective theory of mind (aToM) performance and aberrant neural activation in the ToM brain network partly explain social functioning impairments. However, it is not yet known whether psychotherapy of BD influences neuroimaging markers of aToM.Methods: In the present study conducted within the multicentric randomized controlled trial of the BipoLife consortium, euthymic BD patients underwent two group interventions over 6 months (M = 28.45 weeks): a specific, cognitive-behavioral intervention (SEKT, n = 31) targeting impulse regulation, ToM, and social skills versus an emotion-focused intervention (FEST, n = 28). To compare the effect of SEKT and FEST on neural correlates of aToM, patients performed an aToM task during functional magnetic resonance imaging before and after interventions (final fMRI sample of pre- and post-completers, SEKT: n = 16; FEST: n = 17). Healthy controls (n = 32) were scanned twice with the same time interval. Since ToM was trained in SEKT, we expected an increased ToM network activation in SEKT relative to FEST post-intervention. Results: Both treatments effectively stabilized patients’ euthymic state in terms of affective symptoms, life satisfaction, and global functioning. Confirming our expectations, SEKT patients showed increased neural activation within regions of the ToM network, the bilateral temporoparietal junction (TPJ), the posterior cingulate cortex (PCC), and the precuneus, whereas FEST patients did not. Conclusions: The stabilizing effect of SEKT on clinical outcomes went along with increased neural activation of the ToM network, while FEST possibly exerted its positive effect by other, yet unexplored routes.