Dr Mendis, after completing his education in Sri Lanka, proceeded to the United Kingdom and undertook training in medicine in Birmingham and London, where he was awarded the membership of the Royal College of Psychiatrists, UK.
Following his return to Sri Lanka in his capacity as Consultant Psychiatrist, he has been actively engaged in clinical practice and also he professionally functions at the National Council for Mental Health since his appointment as its Director in 2009 and promoted as President in 2014. He is responsible for the development, planning, reviewing and implementation and management of all professional programmes and activities of the Mental Health Resource Centre and all other professional programmes conducted by the National Council for Mental Health.
Dr. Mendis has been an active speaker, reviewer and Consultant in Psychiatry and Mental Health and involved in mental health awareness and training, conducting training workshops, delivering guest lectures, contributing to the media and participated in a number of television and radio programmes. He is an exponent of the strategy that mental health policies should not be solely concerned with mental health disorders, but also recognize and address the broader issues which promote mental health.
His current interests include electroconvulsive therapy and aspects of mind and body interaction and also optimization of mental health care/mental health clinical research through the training of community based health human resources in primary care.
His singular and unique contribution towards the development of mental health and mental health care has been given due recognition nationally and internationally.