| Term | Definition |
| Dsm-Iv | the fifth Verison of the American psychiatric Associations Diagnostic and Statistical Manual of Mental Disorder. |
| Anxiety | a vague, generalized apprehension or feeling that one is in danger. |
| Phobia | an intense and irrational fear of particular object or situation. |
| Panic disorder | an extreme anxiety that manifests itself in the form of a panic attacks. |
| Post-traumatic stress disorder | disorder in which victims of traumatic events experience the original event in the form of dreams of flashbacks. |
| Somatoform disorder | physical symptoms for which there is no apparent physical cause. |
| conversion disorder | changing emotional difficulties into a loss of a specific voluntary body function. |
| Dissociative disorder | a disorder in which a person experiences alterations in memory, identity, or consciousness. |
| Dissociative amnesia | the inability to recall important personal events of information; is usually associated with stressful events. |
| Dissociative fugue | a dissociative disorder in which a person suddenly and unexpectedly travels away from home or work and is unable to recall the past. |
| Dissociative identity disorder | a person exhibits two or more personality states each with its own patterns of thinking and behaving. |
| Schizophrenia | a group of disorders characterized by confused and disconnected thoughts, emotions, and perceptions. |
| Delusions | false beliefs that a person maintains in the face of contrary evidence. |
| Hallucinations | perceptions that have no direct external cause. |
| Major depressive | sever form of lowered moor in which a person experiences feelings of worthless and diminished pleasure or interest in many activities. |
| Bipolar disorder | disorder in which an individual alternates between feelings of mania (euphoria) and depression. |
| Personality disorder | maladaptive of inflexible ways of dealing with others and one's environment. |
| Antisocial personality disorder | a personality disorder characterized by irresponsibility, shallow emotions, and lack of conscience. |
| Psychological dependence | use of drugs to such an extent that a person feels nervous and anxious without it. |
| Addiction | a pattern of drug abuse characterized by an overwhelming and compulsive desire to obtain and use the drug. |
| Tolerance | physical adaptation to a drug so that a person needs an increased amount in order to produce the original effect. |
| Withdrawal | the symptoms that occur after a person discontinues the use of a drug to which he or she becomes addicted. |