Chaturaka Rodrigo

Chaturaka Rodrigo

University of Colombo, Sri Lanka

Title: Psychiatric morbidity of cannabis use: Neurobiology and implications on policy development


Chaturaka Rodrigo is currently working as a lecturer at the Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Sri Lanka. He graduated with MBBS (Hons) in 2007 from University of Colombo and is currently reading for his MD (Medicine) as a post-graduate trainee. He has 32 publications in indexed reputed international journals and 17 research papers presented at national and international scientific conferences published as abstracts. He is an author of three books and was an invited speaker at the International Forum of Quality and Safety in Healthcare 2011 at Amsterdam, Netherlands.


An epidemiological association between cannabis use and development of schizophrenia spectrum disorders (SSD) has been demonstrated in several studies over the last two decades. This risk is significantly more for males. In a retrospective analysis of over 3600 patients seeking treatment for a psychiatric disorder in Sri Lanka, we have demonstrated that 2.83% of the sample reported life time cannabis (LTC) use. During a follow up period of up to nine years, 16% (576) of this total cohort was diagnosed with a SSD. Male sex and LTC use were significantly associated with being diagnosed with a SSD (p<0.01 and 0.001 respectively). In the majority (91.5%), cannabis use preceded the diagnosis. There are three schools of thought regarding the association of cannabis and SSD; a) cannabis use causes SSD; b) patients with SSD are attracted to cannabis use; and c) cannabis use induces SSD in a minority with background vulnerability. The theory of background vulnerability has been explored in recent research. Still, the exact nature of this vulnerability is unclear (e.g. genetic, environmental or a combination of these). Though cannabis is often portrayed in media as a relatively harmless drug, these issues have to be considered when determining the legal policy regarding cannabis use (decriminalization versus banning). The proposed talk will cover the aspects of epidemiological evidence for an association between SSD and cannabis, neurobiological theories regarding this association and dilemmas in determining the legal status of cannabis use based on the speaker’s experience with research in to this subject.