Caring for a person with dementia can be challenging over the years. To support family carers throughout their entire caregiving career, interventions with a sustained effectivity are needed. A novel 6-week mobile health (mHealth) intervention using the experience sampling method (ESM) showed positive effects on carers' well-being over a period of 2 months after the intervention. In this study, the effects after 6 months of the selfsame intervention were examined to evaluate the sustainability of positive intervention effects.