ASSESSING SOMATIZATION DISORDER IN THE CHRONIC FATIGUE SYNDROME

This study was conducted to examine the rates of somatization disorder (SD) in the chronic fatigue syndrome (CFS) relative to other fatiguin g illness groups. It further addressed the arbitrary nature of the jud gments made in assigning psychiatric vs. physical etiology to symptoms in controversial illnesses such as CFS. Patients with CFS (N = 42), m ultiple sclerosis (MS) (N = 18), and depression (N = 21) were compared with healthy individuals (N = 32) on a structured psychiatric intervi ew. The SD section of the Diagnostic Interview Schedule (DIS) III-R wa s reanalyzed using different criteria sets to diagnose SD, All subject s received a thorough medical history, physical examination, and DIS i nterview. CFS patients received diagnostic laboratory testing to rule out other causes of fatigue. This study revealed that changing the att ribution of SD symptoms from psychiatric to physical dramatically affe cted the rates of diagnosing SD in the CFS group. Both the CFS and dep ressed subjects endorsed a higher percentage of SD symptoms than eithe r the MS or healthy groups, but very few met the strict DSM-III-R crit eria for SD. The present study illustrates that the terminology used t o interpret the symptoms (ie, psychiatric or physical) will determine which category CFS falls into. The diagnosis of SD is of limited use i n populations in which the etiology of the illness has not been establ ished.