Cognitive behavior therapy: A therapeutic practice that helps patients recognize and remedy dysfunctional thought patterns. One characteristic technique is exposure and response prevention, in which a patient with a phobia deliberately exposes himself or herself to the feared situation, gradually decreasing the panic response. Cognitive behavior therapy is used to treat obsessive-compulsive disorder, panic disorder, and other biologically based psychiatric illnesses, often in combination with medication. Evidence gathered from brain scans indicates that over time this therapy can sometimes create actual changes in brain and neurotransmitter function. Abbreviated CBT.