Acceptance and commitment therapy for individuals with depressive and anxiety symptoms following acquired brain injury: A non-concurrent multiple baseline design across four cases.

Only four people were treated and there was no comparison group, so the changes cannot be attributed to the therapy rather than to time passing or to other things happening in these people's lives. Consecutive daily ratings were strongly correlated with each other in six of the phases, which the authors say can make the overlap statistic overestimate how large the effect was. Therapists rated their own adherence to the treatment protocol rather than an independent rater, and one participant received only 60% of the planned exercises and metaphors, below the 80% the authors consider acceptable. For one participant the researcher filled in the weekly follow-up ratings on his behalf because he no longer wanted to answer them, and for another the first 16 days of anxiety ratings were replaced with his average because he had misunderstood the question. The two participants with stroke were relatively young and three of the four had a high education level, so the findings may not apply to older stroke patients or to people with less education. Improvements in anxiety and depression showed up on one questionnaire (the HADS) but not on the other (the DASS-21), where scores were lower to begin with. Psychological flexibility and valued living did not improve, and the authors note that the questionnaire used to measure psychological flexibility may in fact be measuring distress. The study cannot say whether ACT works differently for stroke than for traumatic brain injury.

Funded by ZonMW, a Dutch research funder (project number 636310003). The paper states the funder had no role in the study design, data collection, data analysis, data interpretation, or writing of the manuscript.

Do not conclude that this eight-session ACT programme works for depression and anxiety after brain injury. Three of the four participants improved, but one did not improve on depression at all, and by follow-up his questionnaire scores were higher than before treatment. Also do not assume that better mood means better daily participation: participation and valued living did not clearly improve in any of the four.