A Few Methodologic Issues of Note

Abstract

the avolitional pathology described by Kraepelin 1 is a core pathology affecting some, but not all, persons with schizophrenia. Parenthetically, the ‘‘not all’’ arises from present day emphasis on reality distortion symptoms as diagnostic criteria regardless of the presence of avolitional pathology. The negative symptom construct is broader than avolition and may be usefully dissected, eg, into restricted affect and reduced drive. 2,3 These primary negative symptoms are a direct expression of the disease process independent of reality distortion. It is alsolikely thatall authors believe thatsecondarynegative symptoms also occur. That is, negative symptoms with causes other than the direct pathophysiology of the illness. Common examples include anhedonia secondary to depression, diminished social engagement secondary to paranoia, constricted facial affect caused by antipsychotic drugs (ie, akinesia), and low interest and activity secondary to sedative side effects of therapeutic medication. Despite a seeming consensus on this issue, 2 most articles reporting negative symptoms use rating scales that do not distinguish between primary and secondary negative symptoms. And most of these report their findings without any mention of the primary/secondary negative symptom confound. This axe has been to the grinder on many previous occasions with only modest effect. 4–14