| Term | Definition |
| psychological disorder | deviant, distressful, and dysfunctional behavior patterns |
| attention-deficit hyperactivity disorder (ADHD) | psychological disorder marked by the appearance by age 7 of one or more of three key symptoms: extreme inattention, hyperactivity, and impulsivity |
| medical model | concept that diseases have physical causes that can be diagnosed, treated, and in most cases, cured |
| DSM- IV | American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders |
| anxiety disorders | psychological disorders characterized by distressing, persistent anxiety or maladaptive behaviors that reduce anxiety |
| generalized anxiety disorder | anxiety disorder in which a person in continually tense, apprehensive, and in a state of autonomic nervous system arousal |
| panic disorder | anxiety disorder marked by unpredictable minutes-long episodes of intense dread in which a person experiences terror and accompanying chest pain, choking, or other frightening sensations |
| phobia | anxiety disorder marked by a persistent, irrational fear and avoidance of a specific object or situation |
| obsessive-compulsive disorder (OCD) | anxiety disorder characterized by unwanted repetitive thoughts and/or actions |
| post-traumatic stress disorder (PTSD) | anxiety disorder characterized by haunting memories, nightmares, social withdrawal, jumpy anxiety, and/or insomnia that lingers for four weeks or more after a traumatic experience |
| mood disorders | psychological disorders characterized by emotional extremes |
| major depressive disorder | mood disorder in which a person experiences, in the absence of drugs or medical condition, two or more weeks of significantly depressed moods, feelings of worthlessness, and diminished interest or pleasure in most activites |
| mania | mood disorder marked by hyperactive, wildly optimitic state |
| bipolar disorder | mood disorder in which the person alternates between the hopelessness and lethargy of depression and the overexcited state of mania |
| schizophrenia | group of disorders characterized by disorganized and delusional thinking, disturbed perceptions, and inappropriate emotions and actions |
| delusions | false beliefs, often persecution or grandeur, that may accompany psychotic disorders |
| personality disorders | psychological disorders characterized by inflexible and enduring behavior patterns that impair social functioning |
| antisocial personality disorder | personality disorder in which the person exhibits a lack of conscience for wrongdoing |