Neurosis

1. (Med.) A functional nervous affection or disease, that is, a disease of the nerves without any appreciable change of nerve structure.
2. (Psychiatry) a mental or emotional disorder that affects only part of the personality, and involves less distorted perceptions of reality than a psychosis. As used in medicine, anxiety is a prominent characteristic, and the condition may be accompanied by psychosomatic symptoms. Phobias and compulsive behavior are common varieties.