Abnormal behaviour

Abstract

At the outset of their study of psychology students often expect the subject to be mainly concerned with abnormal states of behaviour. ‘Madness’ is the ubiquitous colloquial expression that appears in people’s definitions of what psychology is about. However, the study and treatment of abnormal states is the central concern of psychiatry and not of psychology. Psychologists define abnormality as a deviation from the normal state, where psychiatrists use the term ‘illness’ to describe a categorically different condition from ‘health’. Indeed the notion of mental illness derives from the fact that psychiatry is a branch of medical science that is founded on the study of physical illnesses and disease states.