Mental illnesses are characterised by health conditions manifesting changes in thinking, emotion, behaviour or a combination of these entities. Mental illnesses are associated with problems of functioning in social, work or family activities. According to US data on Mental illness 19% of adults experience mental illness, 4.1 % have serious illness and 8.5 % have a substance use disorder. Health is defined as not only of physical well-being but also mental well-being. In contrast to common conception, mental illness is treatable and they are able to function in the society like other people. They can pursue education, work involving labour or where physical skill is required. It is worth mentioning that many of the patients are so intelligent that they can function with great intelligence when they are in remission.