Independent mental capacity advocates will begin work across England today as the first stage of the Mental Capacity Act 2005 is implemented.
Imcas will help people without family or friends make decisions about serious medical treatment and changes in residence.
Local authorities and NHS trusts will be required to appoint an Imca in these circumstances and take their views into account.
Imca services have been commissioned from the voluntary sector by councils and primary care trusts.
The rest of the act will be implemented in October.
Mental health information