Health Secretary Alex Neil hailed the link worker project as being "right on the front-line of the battle against health inequalities".
Seven surgeries in poorer areas have link workers based in them, with GPs able to refer patients on to them if they have problems which require more than just medical treatment.
Link workers try to help people struggling with financial, emotional or environmental problems, which could be linked to issues such as housing, debt, stress or fuel poverty.
They can provide advice and put people in contact with other organisations for support.
Mr Neil said the link workers help give people "the chance to live happier lives, with less chance of illness further down the road".
The scheme was launched in September last year and was initially due to run until March 2015. Each surgery taking part in the pilot scheme receives £50,000 a year to pay for the link workers and practice development.
Mr Neil yesterday visited one of the GP surgeries involved, the Allander Practice in Glasgow, where he met doctors, link workers and patients.
The Health Secretary said: "This is about giving people an extra helping hand to address the problems that are making them feel unwell.
"I'm delighted to be able to announce extra funding for the programme to 2018. A full evaluation will be carried out and we will then decide whether or not to extend it to GP practices across the country."