Character disturbance more burdensome to those around him than to the patient himself. The conscience is underdeveloped, and the patient is untrustworthy and inclined to criminal behaviour. A psychopath must fulfil his needs. His tolerance of frustration is low: small annoyances or disappointments make him ill. Psychopaths cannot imagine anyone else’s situation, or enter into long, deep relationships. Other people are objects used for his satisfaction. Treatment is made difficult by the fact that everything that goes wrong in the patient’s life is ascribed to others, and never to himself. One cause of psychopathy can be lack of affection or teaching in early life. A certain amount of trust in other people is needed to form a conscience and the ability to place oneself in other people’s shoes; love, security and a structured life in early childhood are essential for this. Psychopathy sometimes occurs as a result of personality decay after a serious brain injury. In such cases the patient was normal before the injury. Brain damage as a result of poisoning or addiction”’ can also cause the condition; treatment is extremely difficult.