Public health minister Michael Matheson said such prejudice was “unacceptable” in modern Scotland and sufferers should feel they were able to speak out.
The £4.5 million scheme, funded by Comic Relief and the Scottish Government, will help raise awareness and deliver local activities that challenge the discrimination associated with mental ill-health.
It has been backed by a woman whose battle with depression and schizophrenia left her feeling alienated.
Lynsey Pattie, 21, from Motherwell, who was diagnosed with depression aged 15 and schizophrenia when she was 18, now volunteers with the Scottish Association for Mental Health (SamH).
She said: “I’ve experienced mental health problems for most of my life and was hospitalised for ten months, so I know how it feels to deal with the stigma of mental ill-health. I’ve lost friends and have felt alienated by people who don’t understand that, despite my illness, I’m still the same person.
“I know first-hand that, with the right facts and information, the stigma of mental ill-health can be reduced, which is why this new campaign is crucially important for the one in four Scots living with mental health problems.”
The project is being led by SamH and the Mental Health Foundation.
Isabella Goldie, the foundation’s Scottish chief, said: “Many people experiencing mental health problems find that they are avoided by those closest to them and most able to help – their family and friends – and as a result can face their difficulties alone.
“Most of us have trouble coping at times, and mental health problems are common enough that most of us will know somebody who has been affected in some way. However, feelings of shame can prevent people from seeking help and discrimination can greatly limit opportunities in employment, education and even to good-quality healthcare.”
SamH chief executive Billy Watson said: “Every year, one in four people in Scotland will experience a mental health problem and it is imperative that we work towards eliminating the stigma and discrimination that currently exists.”
Gilly Green, Comic Relief’s head of UK grants, said: “Through the new programme, we can work towards breaking down one of the last forms of discrimination still faced daily by people all over Scotland and the rest of the UK.”
Mr Matheson said: “We believe it is unacceptable for people with mental health problems to be faced with discrimination.
“We are committed to building on the work of our high-profile See Me campaign to end all forms of mental health discrimination in Scotland.
“We must ensure that nobody is unwilling to seek help due to stigma, or fear of stigma, around mental health.”