title: Acceptance and Commitment Therapy for Depression after Psychosis: autobiographical memory specificity and rumination as candidate mechanisms of change: and Clinical research portfolio
Creators: name: McKenzie, Christopher
Publisher: name: University of Glasgow
Year: 2019
Subjects: subject: acceptance and commitment therapy, acceptance, depression, schizophrenia, psychosis, depression after psychosis, mechanisms of change, mechanism, autobiographical memory, rumination

description: Background: Understanding how interventions work is a key step in the development and evaluation of complex interventions. Based on previous research, autobiographical memory specificity and rumination are candidate mechanisms of change. Our aim was to explore mechanisms of therapeutic change in the context of a pilot trial of Acceptance and Commitment Therapy (ACT) for people with a diagnosis of schizophrenia and major depression. Method: The ACT for Depression After Psychosis Trial (ADAPT; Gumley et al., 2017) provided repeated measures data that allowed exploration of the change process in ACT for depression after psychosis. Participants who met criteria for schizophrenia and major depression were randomly allocated to standard care or standard care plus up to 5-months of individual ACT for depression after psychosis (ACTdp). Primary outcomes administered on entry to the study (pre-randomisation), at 5-months (posttreatment), and at 10-months (follow up) included the Beck Depression Inventory (BDI), Calgary Depression Scale for Schizophrenia (CDSS), the Kentucky Inventory of Mindfulness Skills (KIMS), and the Acceptance and Action Questionnaire (AAQ). Candidate mechanisms of change were assessed using Ruminative Response Scale (RRS) and the Autobiographical Memory Test (AMT). Results: Significant correlations between change scores were found for BDI and proposed mechanisms of change at 5-months (Rumination: r = 0.60, p&lt; .05; Overgeneral memory responses: r = 0.67, p &lt; .05; memory recall latency: r = -0.84, p&lt; .01) and 10-months (Rumination: r = 0.80, p &lt; .01; Overgeneral memory responses: r = 0.61, p &lt; .01). Changes in CDSS depression and rumination scores were significantly correlated at 10-months (Rumination: r = 0.76, p &lt; .01). In order to examine hypotheses that aspects of autobiographical memory specificity would vary by treatment group, cue word valence, and time of assessment, three-way mixed ANOVAs were performed for percentage of overgeneral memories recalled, and emotional tone of events recalled. Significantly more overgeneral responses were recalled for negative cue words (F (1, 22) = 17.817, p &lt; .001, partial eta squared = .447). Additionally, significantly more negative feeling was evoked for memories recalled in response to negative cue words (F (1, 17) = 83.232, p &lt; .001, partial eta squared = .839). A threeway interaction was found for cue word x time point x treatment group’s effect on feeling evoked by memories recalled (F (2, 15) = 6.251, p &lt; .013, partial eta squared = .455). Post-hoc analysis found the negative feeling evoked by memories recalled in response to negative cue words was significantly reduced in the ACT group posttreatment. For the ACT group, the difference between mean feeling evoked to negative cue words at baseline and 5-months was 2.72, (95% CI [-5.115, -0.318], p &lt; .013). Application: This study provides insight into the change mechanisms through which interventions like ACTdp may produce beneficial effects. Preliminary findings suggest ACT may facilitate positive change for those experiencing depression after psychosis by reducing cognitive avoidance and enhancing ability to tolerate recollection and discussion of emotionally challenging events.