The current policy guidelines on mental health aim to keep the mentally ill within the community, with the development of social support, including families, hence the emergence of the role of the family caregiver.

To identify socio-demographic variables influencing anxiety, depression and stress for the informal caregivers of the mentally ill; to determine the influence of family background variables on caregiver anxiety, depression and stress; to analyse the relationship between social support and caregiver overload with caregiver anxiety, depression and stress.

Cross-sectional, descriptive and correlational study with 104 caregivers, mostly female (62.5%), aged between 22 and 77 years with a mean age of 52.03 years. The following were used as instruments: the Family Apgar Scale; the Satisfaction with Social Support Scale (ESSS); the Caregiver Overload Scale (ESC); the Anxiety, Depression and Stress Scales (EADS-21).

We found that females have higher rates (P<.05) of anxiety, depression and stress; participants with less education have more anxiety than those with higher and secondary education (P=.001); caregivers living in rural areas have higher levels of depression (P=.044) and stress (P=.041); those who perceive belonging to families with marked dysfunctions have higher levels of depression (P=.0.001) and stress (P=.000); the higher the overload, the higher the levels of anxiety (P=.002), depression and stress (P=.000).

I tis necessary to develop strategies for local and community intervention to promote mental health and prevent mental illness.