Mindfulness-based cognitive therapy (MBCT) is a psychotherapeutic intervention that has been shown effective in several clinical conditions. Nevertheless, research is still needed on its effectiveness on cognition.

To analyze possible effects on cognition of the addition of MBCT intervention versus a brief structured group psycho-education to the standard treatment of subsyndromal bipolar depression. Our hypothesis was that MBCT could improve some aspects of cognitive function to a higher degree than psycho-education and treatment as usual (TAU).

A randomized, multicenter, prospective, versus active comparator, evaluator-blinded clinical trial was conducted. Forty patients with BD and subclinical or mild depressive symptoms were randomly allocated to:

– MBCT added to psychopharmacological treatment (n = 16);

– a brief structured group psycho-educational intervention added to psychopharmacological treatment (n = 17);

– standard clinical management, including psychopharmacological treatment (n = 7).

Assessments were conducted at screening, baseline, post-intervention (8 weeks) and 4-month follow-up.

Cognition results point to significant improvement in Stroop Color test as well as processing speed in TMT A test (P < 0.05) in the two psychological intervention groups versus TAU.

These preliminary findings suggest that the addition of MBCT or psycho-education to usual treatment could improve some cognitive dimensions in subsyndromal bipolar depressive patients.

The authors have not supplied their declaration of competing interest.