Aim: To define psychopathy and discuss psychological theories relating to psychopathy.We all think that we know what a psychopath is. This is a term bandied about by themedia, films, cinemas, and so on. So before we continue, let us clarify someimportant terms.Mental illness in the Western World tends to be classified in accordance with theDSM (Diagnostic and Statistical Manual of Mental disorders) published by theAmerican Psychiatric Association. It is regularly updated. The DSM uses fivedimensions to diagnose mental illness.Axis 1 – Clinical Syndromes: this includes items such as depression, schizophreniaand social phobia.Axis II – Personality Disorders and Developmental Disorders: included here isautism, learning disabilities, and so on, but also personality disorders, such asantisocial personality disorder, dependent personality disorder, and so on.Axis III – Physical Conditions - these are physical conditions that can affectconditions in Axis I and II, such as brain injury, HIV/AIDS.Axis IV – Severity of Psychosocial Stressor – these are events that happen in ourlives that affect Axis I and Axis II, such as bereavement, unemployment and so on.Axis V – Highest level of Functioning – here the psychologist or psychiatrist looks atthe person's level of functioning now and at the highest level over the previous year,to help the clinician determine how the axes are affecting the person.