A recent Cochrane review examined the effectiveness of Mindfulness-Based Stress Reduction (MBSR) techniques for reducing stress in family carers of people with dementia. The authors concluded cautiously that MBSR might help to reduce depressive symptoms and anxiety among carers (in the short-term at least). As usually happens, the authors of this review caution readers about the poor quality of the evidence available.
Liu, Z. Sun, YY. [and] Zhong, BL. (2018). Mindfulness-based stress reduction for family carers of people with dementia. Cochrane Database of Systematic Reviews. August 14th 2018; 8: CD012791. [Epub ahead of print].
There is also an Executive Summary.