Sustained Attention as Mediator in Mindfulness-Based Cognitive Therapy for Depression
Clinical Psychiatry, Psychotherapy, Child and Adolescent Psychiatry
Final Report Abstract
Mindfulness-based interventions have proved effective in reducing various clinical symptoms and in improving general mental health and well-being. The investigation of the mechanisms of therapeutic change needs methods for assessment of mindfulness. Existing self-report measures have, however, been strongly criticized on various grounds, including distortion of the original concept, response bias, and other. We propose a psychophysiological method for the assessment of the mindfulness learned through time-limited mindfulness-based therapy by people who undergo meditation training for the first time. We use the individual pre-post-therapy changes (dERPi) in the event-related brain potentials (ERPs) recorded in a passive meditation task as a measure of increased mindfulness. dERPi is computed through multivariate assessment of individual participant's ERPs. For this purpose, we adopted a multivariate approach proposed by Bostanov & Kotchoubey (2006), based on Bostanov (2004), which allowed us to quantify the difference between the pre-therapy ERP and the post-therapy ERP by representing the single-trial ERPs as points in a vector space and computing the geometric distance between the two sample means for each participant. We developed the work of Bostanov (2004) and Bostanov & Kotchoubey (2006) further and published the results in a more detailed mathematical technical article where we provided a didactic geometric primer on some basic concepts of multivariate statistics as applied to ERP assessment in general and to the t-CWT method in particular. In this publication, we also presented for the first time a detailed, step-by-step, formal description of the t-CWT algorithm and discussed some conceptually novel applications of the multivariate approach in general and of the t-CWT method in particular for the purpose of hypothesis testing in ERP research. We tested the proposed method in a group of about 70 recurrently depressed participants, randomly assigned in 1.7:1 ratio to mindfulness-based cognitive therapy (MBCT) or cognitive therapy (CT). The therapy outcome was measured by the long-term change (dDS) relative to baseline in the depression symptoms (DS) assessed weekly, for 60 weeks, by an online self-report questionnaire. We found a strong, highly significant, negative correlation (r = −0.55) between dERPi (mean = 0.4) and dDS (mean = −0.7) in the MBCT group. Compared to this result, the relationship between dDS and the other (self-report) measures of mindfulness we used was substantially weaker and not significant. So was also the relationship between dERPi and dDS in the CT group. The interpretation of dERPi as a measure of increased mindfulness was further supported by positive correlations between dERPi and the other measures of mindfulness. In this study, we also replicated a previous result, namely, the increase (dLCNV) of the late contingent negative variation (LCNV) of the ERP in the MBCT group, but not in the control group (in this case, CT). We interpreted dLCNV as a measure of increased meditative concentration. The relationship between dLCNV and dDS was, however, very week, which suggests that concentration might be relatively unimportant for the therapeutic effect of mindfulness. The proposed psychophysiological method could become an important component of a “mindfulness test battery” together with self-report questionnaires and other newly developed instruments. We published these results in a very detailed article in which we also discussed some generic problems of assessment arising from the very nature of mindfulness. Some results from this DFG-funded project as well as from our previous one were reported in the ARD TV documentary series “W wie Wissen” (https://www.daserste.de/information/wissen-kultur/w-wie-wissen/sendung/gedanken-100.html) and in the feature length documentary movie “STOPPING – wie man die Welt anhält – Wege zur Meditation” (http://www.stoppingderfilm.org/).
Publications
- (2015). Multivariate assessment of event-related potentials with the t-CWT method. BMC Neurosci
Bostanov V.
(See online at https://doi.org/10.1186/s12868-015-0185-z) - (2018). Measuring Mindfulness: A Psychophysiological Approach. Frontiers in human neuroscience, 12, 249
Bostanov, V., Ohlrogge, L., Britz, R., Hautzinger, M., & Kotchoubey, B.
(See online at https://doi.org/10.3389/fnhum.2018.00249)
