Psychology is the study of human behaviour, cognition, and emotion. Psychologists are professionals trained to assess and diagnose issues of mental health, as well as learning and developmental differences. They also provide psychotherapy to address both difficulties of mental health and issues of daily living. In Ontario, psychologists are regulated health professionals registered with College of Psychologists and Behaviour Analysts of Ontario. Educational material about psychologists and their many roles can also be found at the Canadian Psychological Association.