AFFECTIVE DEFICITS AND PAIN INSENSITIVITY IN SCHIZOPHRENIA

Affective deficits have long been considered a prominent feature of sc hizophrenia and play a central role in recent theory and research on t he pathophysiology of this disorder. However, it has recently been arg ued that current approaches to the conceptualization and assessment of affective flattening in schizophrenia are confounded by the social an d neuromotor deficits that are also prevalent in this disorder. Insens itivity to pain in individuals with schizophrenia - a phenomenon that has been reported frequently but never systematically investigated -pr ovides one approach to examining affective flattening unconfounded by social and neuromotor deficits. Two studies are described in which sig nal detection theory measures of thermal pain sensitivity were examine d in patients with schizophrenia, mood disorder, and normal controls; in addition, in the patients with schizophrenia, the relationships bet ween these measures and measures of affective deficits were examined. Patients with schizophrenia had significantly poorer sensory discrimin ation of painful thermal stimuli than control subjects, but did not di ffer from controls with respect to their response criterion for report s of pain; patients with mood disorder had a significantly higher (i.e ., more stoical) criterion for reports of pain than controls. As predi cted, among the patients with schizophrenia, higher response criterion was significantly correlated with greater affective flattening and le ss intense affective experience (as well as with fewer positive sympto ms and poorer premorbid adjustment). The results of these studies sugg est that pain insensitivity in schizophrenia may reflect affective as well as sensory abnormalities, and that pain insensitivity in schizoph renia may provide a method for studying affective flattening in this d isorder that is relatively independent of the social and neuromotor de ficits that confound existing measures of this symptom. Continued exam ination of the relationship between pain insensitivity and affective d eficits in schizophrenia is also important because numerous clinical r eports have suggested that pain insensitivity is detrimental to health and can have life-threatening consequences in individuals with this d isorder.