Estonian study: Cannabis tends to affect the mental health of ever younger people By 47 shares Recreational use of cannabis is increasing worldwide, including in Estonia; a study by medical researchers of the University of Tartu shows that the first use of cannabis in Estonia is taking place in increasingly younger age groups – more and more people try cannabis before the age of 16, and from the point of view of brain development, this is too early. Medical researchers from the University of Tartu, led by an associate professor in psychiatry, Liina Haring, and a professor of human physiology, Eero Vasar, have concluded the results of the extensive survey “Drugs and Developing Brains”. The survey, which involved 4,922 Estonian people, assessed cannabis use among 16-45-year-olds and analysed whether and to what extent the psychopathological symptoms of cannabis users and non-users differ.