Canadian Psychiatric Association


Ottawa, ON, April 12, 2017 – With the federal government set to legalize marijuana on or before July 1, 2018, the Canadian Psychiatric Association (CPA) has released a statement today highlighting the importance of safeguarding the mental wellness of youth and young adults in the forthcoming legislation.

“There is a strong evidence-base showing that early and regular cannabis use can affect cognition, such as memory, attention, intelligence and the ability to process thoughts and experiences,” says CPA President, Dr. Renuka Prasad. “It can also increase the risk of developing a primary psychotic disorder as well as other mental health issues such as depression in those who are already vulnerable to these disorders.”

Research shows that the human brain continues to develop until around the age of 25, therefore psychiatrists are concerned that the regular use of cannabis prior to that age may negatively affect the brain’s healthy maturation process.

For this reason the CPA recommends in its position statement, Implications of Cannabis Legalization on Youth and Young Adults, that Canadians should not be legally allowed to use marijuana until the age of 21, and that legislation should restrict the quantity and potency of the drug until they are 25.

“Cannabis with high tetrahydrocannabinol (THC) content can result in significantly worse mental health and cognitive outcomes, including worsening of panic disorder and other anxiety disorders,” says Dr. Phil Tibbo, lead author of the statement and member of the CPA’s Research Committee. Dr. Tibbo is also head of the Nova Scotia Early Psychosis Program.

The CPA believes legislation should address the need for public education targeting youth and young adults around the effects early cannabis use can have on brain development.

The statement is supported by the Canadian Academy of Child and Adolescent Psychiatry, the Canadian Academy of Geriatric Psychiatry, the Canadian Academy of Psychiatry and the Law, and the Canadian Academy of Psychosomatic Medicine.

“The legalization of cannabis is only about 15 months away and we need to be ready for its potential impact on the mental health of our youth,” says Dr. Prasad. “The CPA is willing and prepared to work with the government on critical components of the legislation related to research, public education, and harm reduction.”

Read CPA’s position statement, Implications of Cannabis Legalization on Youth and Young Adults, at


The Canadian Psychiatric Association is the national voice for Canada’s 4,700 psychiatrists and more than 900 psychiatric residents. Founded in 1951, the CPA is dedicated to promoting an environment that fosters excellence in the provision of clinical care, education and research.