This is a feasibility study to evaluate whether it is possible to conduct a larger study to evaluate whether providing psychological support to carers of people with MS is effective in reducing carer strain. Whilst not all carers experience distress as a result of their caring duties, some do. This study is testing the use of Acceptance and Commitment Therapy (ACT) in a self-help format. Participants will learn about and use ACT by reading a book provided to them by the study. One group will receive the ACT book, another will receive the same book alongside weekly telephone support to use the book, and a third group will act as a control group and therefore will not have extra support. Participants are allocated to the groups based on chance (a computer will decide group allocation). Participants will complete questionnaires before group allocation, and then again 3 months after they were allocated to a group, and one final time 6 months after group allocation. Those who receive the self-help book will get sent chapters each week for 8 weeks. The groups will be compared on scores from the questionnaires and complete feedback interviews with a subgroup of those who receive the book, to gain feedback about their experiences of the study.

Inclusion Criteria:

• primary carer for a person with MS,
• English speaking (intervention and assessments are in English),
• able to give informed consent.
• score at least 21 on the Zarit Burden Interview (demonstrating a minimum of mild distress)

Exclusion Criteria:

• diagnosis of MS themselves
• psychiatric diagnosis
• inability to commit to the intervention