Dr. Mahesan Ganesan is currently a Consultant Psychiatrist at the National Institute of Mental Health, Angoda, Colombo, Sri Lanka. He was registered as a consultant psychiatrist in 1995. 

Prior to his work at the mental Hospital, he worked extensively in the conflict and tsunami affected district of Batticaloa, in Eastern Sri Lanka where he was instrumental in developing a community mental health service model. He spent over 9 years working in Batticaloa. He was responsible for providing services for over 1.4 million people as the only psychiatrist. There were hardly any services as there has not been any psychiatrist in this region for over 20 years. He helped develop a model with minimum resources that has now been implemented. It includes small acute inpatient care units in hospitals; many out reach follow-up clinics, and community work. He was instrumental in developing the concept of GBV desk in Batticaloa district in 2005 and helped to establish similar services in five other hospitals in the Northeast of the country. 

The program also focuses on child protection, drug and alcohol abuse, psychosocial activities, developing services for the learning disabled children (intellectual disability) and more. 

He also serves as a Board Member of Samutthana, Centre for Human Rights and Development, Survivors Associated and Global Initiative in Psychiatry (FGIP) Good practice group, and patron of Ampara special needs network.