Memory Flexibility training (MemFlex) to reduce depressive symptomatology in individuals with major depressive disorder: study protocol for a randomised controlled trial

Proof of Concept for the Autobiographical Memory Flexibility (MemFlex) Intervention for Posttraumatic Stress Disorder

Autobiographical memory distortions are a key feature of posttraumatic stress disorder (PTSD). In this proof-of-concept randomized controlled trial (N = 43), we evaluated an autobiographical memory flexibility intervention, MemFlex. We aimed to determine whether the mechanism-focused intervention, which aims to improve autobiographical memory processes, may also affect other cognitive predictors of PTSD and potentially reduce PTSD symptoms in Iranian trauma survivors diagnosed with PTSD. Results indicated significant, moderate to large between-groups effect sizes in favor of MemFlex, relative to wait-list control, for the targeted cognitive mechanism of autobiographical memory flexibility and PTSD symptoms. A large, significant effect was also observed on maladaptive posttraumatic cognitions-a strong predictor of PTSD prognosis, which is a key target of high-intensity cognitive therapies for PTSD. Findings support future completion of a scaled-up trial to evaluate treatment efficacy of MemFlex for PTSD to determine whether MemFlex may offer a culturally adaptive, low-cost, low-intensity intervention able to improve cognitive mechanisms of PTSD.

Harnessing Mental Imagery and Enhancing Memory Specificity: Developing a Brief Early Intervention for Depressive Symptoms in Adolescence

Background

Treatment innovation for depressive symptoms in adolescence is urgently needed. Adult research suggests interventions targeting underlying cognitive mechanisms, such as dysfunctional mental imagery and overgeneral memory, are promising. Here, we describe and evaluate in a case series a brief imagery-based intervention for depressive symptoms that targets these cognitive mechanisms.

Methods

Nine participants completed the four-session intervention, whose principle components were imagery rescripting and memory specificity training. Questionnaires and experimental tasks (assessing symptomatology and cognitive mechanisms) were administered at three time points: pre-intervention, post-intervention and 3-month follow-up.

Results

The intervention was feasible to deliver and acceptable to participants. There was a large reduction in depression symptom scores from pre to post intervention (d = 1.32; 67% showed reliable improvement, RI) and this was maintained at follow-up (d = 1.46; RI = 75%). There were also reductions in anxiety (post: d = 1.15, RI = 44%; follow-up: d = 1.67, RI = 63%), increases in self-esteem (post: d = − 0.70, RI = 44%; follow-up: d = − 1.20, RI = 50%) and noteworthy changes in memory specificity (post: d = − 1.80, RI = 67%; follow-up: d = − 0.94, RI = 63%).

Conclusions

This is the first study to use imagery rescripting and memory specificity training in adolescence. Initial evidence is provided that the intervention is acceptable and may have clinical utility. Future randomised controlled trials are needed to further assess the intervention.

Circuits that encode and guide alcohol-associated preference

A powerful feature of adaptive memory is its inherent flexibility. Alcohol and other addictive substances can remold neural circuits important for memory to reduce this flexibility. However, the mechanism through which pertinent circuits are selected and shaped remains unclear. We show that circuits required for alcohol-associated preference shift from population level dopaminergic activation to select dopamine neurons that predict behavioral choice in Drosophila melanogaster. During memory expression, subsets of dopamine neurons directly and indirectly modulate the activity of interconnected glutamatergic and cholinergic mushroom body output neurons (MBON). Transsynaptic tracing of neurons important for memory expression revealed a convergent center of memory consolidation within the mushroom body (MB) implicated in arousal, and a structure outside the MB implicated in integration of naïve and learned responses. These findings provide a circuit framework through which dopamine neuronal activation shifts from reward delivery to cue onset, and provide insight into the maladaptive nature of memory.

When I relive a positive me: Vivid autobiographical memories facilitate autonoetic brain activation and enhance mood

Autobiographical memory is vital for our well‐being and therefore used in therapeutic interventions. However, not much is known about the (neural) processes by which reliving memories can have beneficial effects. This study investigates what brain activation patterns and memory characteristics facilitate the effectiveness of reliving positive autobiographical memories for mood and sense of self. Particularly, the role of vividness and autonoetic consciousness is studied. Participants (N = 47) with a wide range of trait self‐esteem relived neutral and positive memories while their bold responses, experienced vividness of the memory, mood, and state self‐esteem were recorded. More vivid memories related to better mood and activation in amygdala, hippocampus and insula, indicative of increased awareness of oneself (i.e., prereflective aspect of autonoetic consciousness). Lower vividness was associated with increased activation in the occipital lobe, PCC, and precuneus, indicative of a more distant mode of reliving. While individuals with lower trait self‐esteem increased in state self‐esteem, they showed less deactivation of the lateral occipital cortex during positive memories. In sum, the vividness of the memory seemingly distinguished a more immersed and more distant manner of memory reliving. In particular, when reliving positive memories higher vividness facilitated increased prereflective autonoetic consciousness, which likely is instrumental in boosting mood.

A randomised controlled trial of memory flexibility training (MemFlex) to enhance memory flexibility and reduce depressive symptomatology in individuals with major depressive disorder

Successful navigation within the autobiographical memory store is integral to daily cognition. Impairment in the flexibility of memory retrieval can thereby have a detrimental impact on mental health. This randomised controlled phase II exploratory trial (N = 60) evaluated the potential of a novel intervention drawn from basic science - an autobiographical Memory Flexibility (MemFlex) training programme - which sought to ameliorate memory difficulties and improve symptoms of Major Depressive Disorder. MemFlex was compared to Psychoeducation (an evidence-based low-intensity intervention) to determine the likely range of effects on a primary cognitive target of memory flexibility at post-intervention, and co-primary clinical targets of self-reported depressive symptoms and diagnostic status at three-month follow-up. These effect sizes could subsequently be used to estimate sample size for a fully-powered trial. Results demonstrated small-moderate, though as expected statistically non-significant, effect sizes in favour of MemFlex for memory flexibility (d = 0.34, p = .20), and loss of diagnosis (OR = 0.65, p = .48), along with the secondary outcome of depression-free days (d = 0.36, p = .18). A smaller effect size was observed for between-group difference in self-reported depressive symptoms (d = 0.24, p = .35). Effect sizes in favour of MemFlex in this early-stage trial suggest that fully-powered evaluation of MemFlex may be warranted as an avenue to improving low-intensity treatment of depression.

TRIAL REGISTRATION

ClinicalTrials.gov, Identifier NCT02371291.

Memory flexibility training for autobiographical memory as an intervention for maintaining social and mental well-being in older adults

Autobiographical memory specificity (AMS) reduces with increasing age and is associated with depression, social problem-solving and functional limitations. However, ability to switch between general and specific, as well as between positive and negative retrieval, may be more important for the strategic use of autobiographical information in everyday life. Ability to switch between retrieval modes is likely to rely on aspects of executive function. We propose that age-related deficits in cognitive flexibility impair AMS, but the "positivity effect" protects positively valenced memories from impaired specificity. A training programme to improve the ability to flexibly retrieve different types of memories in depressed adults (MemFlex) was examined in non-depressed older adults to determine effects on AMS, valence and the executive functions underlying cognitive flexibility. Thirty-nine participants aged 70+ (MemFlex, n = 20; control, n = 19) took part. AMS and the inhibition aspect of executive function improved in both groups, suggesting these abilities are amenable to change, although not differentially affected by this type of training. Lower baseline inhibition scores correlated with increased negative, but not positive AMS, suggesting that positive AMS is an automatic process in older adults. Changes in AMS correlated with changes in social problem-solving, emphasising the usefulness of AMs in a social environment.

Study protocol for a randomised, controlled platform trial estimating the effect of autobiographical Memory Flexibility training (MemFlex) on relapse of recurrent major depressive disorder

INTRODUCTION

Major depressive disorder (MDD) is a chronic condition. Although current treatment approaches are effective in reducing acute depressive symptoms, rates of relapse are high. Chronic and inflexible retrieval of autobiographical memories, and in particular a bias towards negative and overgeneral memories, is a reliable predictor of relapse. This randomised controlled single-blind trial will determine whether a therapist-guided self-help intervention to ameliorate autobiographical memory biases using Memory Flexibility training (MemFlex) will increase the experience of depression-free days, relative to a psychoeducation control condition, in the 12 months following intervention.

METHODS AND ANALYSIS

Individuals (aged 18 and above) with a diagnosis of recurrent MDD will be recruited when remitted from a major depressive episode. Participants will be randomly allocated to complete 4 weeks of a workbook providing either MemFlex training, or psychoeducation on factors that increase risk of relapse. Assessment of diagnostic status, self-report depressive symptoms, depression-free days and cognitive risk factors for depression will be completed post-intervention, and at 6 and 12 months follow-up. The cognitive target of MemFlex will be change in memory flexibility on the Autobiographical Memory Test- Alternating Instructions. The primary clinical endpoints will be the number of depression-free days in the 12 months following workbook completion, and time to depressive relapse.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the NHS National Research Ethics Committee (East of England, 11/H0305/1). Results from this study will provide a point-estimate of the effect of MemFlex on depressive relapse, which will be used to inform a fully powered trial evaluating the potential of MemFlex as an effective, low-cost and low-intensity option for reducing relapse of MDD.

TRIAL REGISTRATION NUMBER

NCT02614326.

Autobiographical episodic memory-based training for the treatment of mood, anxiety and stress-related disorders: A systematic review and meta-analysis

We review evidence for training programmes that manipulate autobiographical processing in order to treat mood, anxiety, and stress-related disorders, using the GRADE criteria to judge evidence quality. We also position the current status of this research within the UK Medical Research Council's (2000, 2008) framework for the development of novel interventions. A literature search according to PRISMA guidelines identified 15 studies that compared an autobiographical episodic memory-based training (AET) programme to a control condition, in samples with a clinician-derived diagnosis. Identified AET programmes included Memory Specificity Training (Raes, Williams, & Hermans, 2009), concreteness training (Watkins, Baeyens, & Read, 2009), Competitive Memory Training (Korrelboom, van der Weele, Gjaltema, & Hoogstraten, 2009), imagery-based training of future autobiographical episodes (Blackwell & Holmes, 2010), and life review/reminiscence therapy (Arean et al., 1993). Cohen's d was calculated for between-group differences in symptom change from pre- to post-intervention and to follow-up. We also completed meta-analyses for programmes evaluated across multiple studies, and for the overall effect of AET as a treatment approach. Results demonstrated promising evidence for AET in the treatment of depression (d=0.32), however effect sizes varied substantially (from -0.18 to 1.91) across the different training protocols. Currently, research on AET for the treatment of anxiety and stress-related disorders is not yet at a stage to draw firm conclusions regarding efficacy as there were only a very small number of studies which met inclusion criteria. AET offers a potential avenue through which low-intensity treatment for affective disturbance might be offered.

The effects of autobiographical memory flexibility (MemFlex) training: An uncontrolled trial in individuals in remission from depression

BACKGROUND AND OBJECTIVES

Impaired cognitive processing is a key feature of depression. Biases in autobiographical memory retrieval (in favour of negative and over-general memories) directly impact depression symptoms, but also influence downstream cognitive factors implicated in the onset and maintenance of the disorder. We introduce a novel cognitive intervention, MemFlex, which aims to correct these biases in memory retrieval and thereby modify key downstream cognitive risk and maintenance factors: rumination, impaired problem solving, and cognitive avoidance.

METHOD

Thirty eight adults with remitted Major Depressive Disorder completed MemFlex in an uncontrolled clinical trial. This involved an orientation session, followed by self-guided completion of six workbook-based sessions over one-month. Assessments of cognitive performance and depression symptoms were completed at pre- and post-intervention.

RESULTS

Results demonstrated medium-sized effects of MemFlex in improving memory specificity and problem solving, and decreasing rumination, and a small effect in reducing cognitive avoidance. No significant change was observed in residual symptoms of depression.

LIMITATIONS

This study was an uncontrolled trial, and has provided initial evidence to support a larger-scale, randomized controlled trial.

CONCLUSIONS

These findings provide promising evidence for MemFlex as a cost-effective, low-intensity option for reducing cognitive risk associated with depression.