In addition, the psycho-education programme reduced carers’ burden of care compared with those who received usual care. The intervention effect was significant and differed over time. Zarit et al (1986) found the burden of care included negative feelings about giving care and impaired physical or psychological health. At four weeks the intervention started to have a positive effect on quality of life and this differed over time, but no intervention effect was found for environment as this has no interaction with psychology or education, that is, the living environment could not become better or worse if the carer had improved or decreased psychological or physical wellbeing.