A Pilot Evaluation of Mindfulness-based Cognitive Therapy for People With Huntington's Disease

Huntingdon's disease (HD) is a genetic neurodegenerative condition which causes problems with movement, coordination and cognitive functioning, and emotional difficulties are also commonly experienced. It is believed to affect around five to ten in 100,000 people of European descent, with recent UK estimates as high as 11.2-13.5. Each child of an affected person has a 50% chance of inheriting the condition. As age of diagnosis is typically around 35-55, with time from diagnosis to death around 20 years, those who are diagnosed have often seen their parents affected by the condition.

Many people at various stages of HD (including those who carry the gene but are pre-symptomatic) experience low mood, anxiety and other psychological difficulties. Indeed, alongside functional capacity, mood may be one of the main factors which contributes to health related quality of life, more so than discrete motor problems, or cognitive impairment. In addition, reports from patients suggest emotional and social concerns are important for individuals with the condition at the pre-symptomatic stage, and these concerns remain throughout the disease course. Medication may be effective to alleviate psychological difficulties for some people, but its efficacy has not been conclusively proven and it is not suitable for all. Psychological interventions may provide an alternative or additional way of alleviating distress.

Although it is commonly presumed that biological factors are the main determinants of psychological distress in people with HD, several studies have indicated that, while these may indeed be important, psychological factors are also significant. For example beliefs about the disease and coping mechanisms are associated with poorer mental health and higher levels of depression. Such psychological beliefs and coping patterns can be adaptively changed using psychological interventions, for example cognitive-based psychological therapies.

Little progress has been reported on the development of psychological interventions in HD despite the fact that people with HD have expressed an interest in psychological approaches and these are currently being successfully developed for people with other neurological conditions (e.g., in people with Parkinson's disease). It is therefore proposed to pilot mindfulness-based cognitive therapy (MBCT) which, although originally developed to help people with remitted depression from relapse, has been increasingly used to help people with current difficulties. It has also been piloted with people with Parkinson's disease who found it an acceptable intervention and reported improvements in self-management and psychological wellbeing. In general, MBCT has also recorded other gains including improved sleep quality and social functioning. It has also received sufficient evidence for it to be a recommended approach in the UK NICE guidelines for people with a history of depression. MBCT can also reduce anxiety and provides group support. There are also indications that mindfulness training can improve neurocognitive functioning, even in people with neurodegenerative disease. Finally, a psychological therapy subgroup within the European Huntington's Disease Network has recently been formed, thus indicating the rise of interest in psychological approaches and the timely nature of this work.

Hence this study will provide the first indication of whether MBCT, a therapeutic approach with an established evidence base, would be acceptable and useful for people with HD. In order to meet this aim, MBCT will be delivered to two groups, one to individuals who carry the gene but are pre-symptomatic and one to individuals who have begun to experience symptoms but are at an early stage of the disease course.

Approaches to outcome evaluation should be incremental, with lower cost studies, e.g., qualitative investigations and case studies, being conducted before investment in randomised controlled trials is considered. Thus this study will follow this guidance by collecting both qualitative and quantitative data. The qualitative data will be analysed using interpretative phenomenological analysis, a methodology previously used in other qualitative studies on MBCT. Semi-structured interviews will provide data on the acceptability of the intervention and detailed accounts of participants' experience after the intervention has been provided. This will inform whether the MBCT intervention needs to be changed or adapted in further trials. The quantitative data will be used to provide basic pre and post intervention comparisons on a number of outcome variables relevant to MBCT, with the hypothesis that performance on these measures will improve post training. These data will also be used to estimate effect sizes for further trials so that these are suitably powered.

Given the considerable physical, cognitive and emotional consequences of the disease, HD not only affects the person with HD, but also those with whom they live, even in the pre-clinical phase. Family members often become caregivers and can have a reduced quality of life as a result, including experiencing low mood themselves. In fact, caregiver burden and caregiver depression is associated with depression of the person with HD and, alongside motor disturbances, depression of the person with HD is one of the main predictors of caregiver burden. Partners of people with HD can also experience reduced satisfaction with their relationship, sometimes more so than the person with HD themselves.

Thus this study will also investigate the views of a family member (e.g. partner, parent, child) of the person participating in the intervention. As the intervention is aimed at alleviating psychological distress in the person with HD, it is hypothesised that this in turn will also have an effect on the family member's wellbeing. Also, higher levels of mindfulness are associated with higher levels of satisfaction in partner relationships, perhaps due to more adaptive conflict resolution and better emotional recognition and management. Participants in MBCT have reported increased empathy and perspective taking, being more able to respond mindfully in relationships. Thus increased mindfulness of the person with HD may benefit family and social relationships.

In addition, caregivers' views about the symptoms or quality of life of the person with HD may not always match the person with HD themselves. Furthermore, certain symptom changes which are beneficial to the person with HD may not be so to the caregiver, and thus the caregiver can offer an alternative perspective of the wellbeing (including behavioural and psychological changes) of the person with HD.

Both qualitative and quantitative data will be collected from a family member or close friend of the person with HD, where such a person is available and willing to take part. Semi-structured interviews with the family member will explore their perceptions on the acceptability of the intervention and experiences of the person with HD, as well as the impact on the family member personally and the wider family system. Data collected pre and post the intervention will assess any changes in their psychological wellbeing, caregiver burden and family relationships, with the hypothesis that wellbeing and relationships will improve post training and caregiver burden will decrease.