The American Psychiatric Association (APA) provides a formal definition of a psychological disorder that incorporates many features from Wakefield's harmful dysfunction model. This definition states that a psychological disorder is a condition involving: 1) significant disturbances in thoughts, feelings, and behaviors; 2) these disturbances reflect an underlying biological, psychological, or developmental dysfunction; 3) they cause significant distress or disability in an individual's life; and 4) they are not expected or culturally approved responses to life events.