The negative symptoms of schizophrenia: a cognitive perspective.

Recent reports of improvement in the negative symptoms of schizophrenia following targeted cognitive interventions have prompted interest in the cognitive underpinnings of these symptoms. This review integrates current experimental research with the phenomenological accounts of patients participating in cognitive therapy for these specific symptoms. We propose that, in addition to the well-established role of neurobiological factors in their development and maintenance, specific cognitive appraisals and beliefs play a role in the expression and persistence of negative symptoms. This cognitive model of negative symptoms is based on a diathesis-stress formulation: a continuum of predispositional traits from the premorbid personality to the full-blown negative symptomatology, the incorporation of negative social and performance attitudes within these traits, and low expectancies for pleasure or success in goal-oriented activities. We suggest that negative symptoms represent, in part, a compensatory pattern of disengagement in response to threatening delusional beliefs, perceived social threat, and anticipated failure in tasks and social activities. A psychological aspect of this motivational and behavioural inertia appears to be the patient's perception of limited psychological resources--a perception that motivates patients to conserve energy by minimizing investment in activities requiring effort.