Persecutory delusions and the conditioned avoidance paradigm: towards an integration of the psychology and biology of paranoia.

INTRODUCTION Theories of delusions often underplay the role of their content. With respect to persecutory delusions, taking threat as fundamental suggests that models of threat-related, aversive learning, such as the Conditioned Avoidance Response (CAR) task, might offer valid insights into the underlying normal and abnormal processes. In this study, we reappraise the psychological significance of the CAR model of antipsychotic drug action; and we relate this to contemporary psychological theories of paranoia. METHODS Review and synthesis of literature. RESULTS Anticipation and recall of aversive events are abnormally accentuated in paranoia. Safety (avoidance) behaviours may help perpetuate and fix persecutory ideas by preventing their disconfirmation. In addition, patients may explain negative events in a paranoid way instead of making negative self-attributions (i.e., in an attempt to maintain self-esteem). This defensive function only predominates in the overtly psychotic patients. The "safety behaviours" of paranoid patients, their avoidance of negative self-attributions, and the antiparanoid effect of antipsychotic medication all resonate with aspects of the CAR. CONCLUSIONS The CAR appears to activate some normal psychological and biological processes that are pathologically activated in paranoid psychosis. Paranoid psychological defences may be a result of basic aversive learning mechanisms, which are accentuated during acute psychosis.