Faculty Bibliography

The authors conducted an investigation in four tertiary-care centers to determine if psychiatric comorbidity and psychological variables were predictive of functional impairment in patients with fibromyalgia syndrome (FMS). Seventy-three individuals were administered the Structured Clinical Interview for DSM-III-R, the Rand 36-item Health Survey (SF-36), and multiple self-report measures. The patients with FMS were found to have a high lifetime and current prevalence of major depression and panic disorder. The most common disorders were major depression (lifetime [L] = 68%, current [C] = 22%); dysthymia (10% [C only]); panic disorder (L = 16%, C = 7%); and simple phobia (L = 16%, C = 12%). The self-report scales revealed significant elevations in depression, anxiety, neuroticism, and hypochondriasis. Functional impairment on all measures of the SF-36 was severe (e.g., physical functioning = 45.5 and role limitations due to physical problems = 20.0). Stepwise multiple-regression analysis revealed that current anxiety was the only variable that predicted a significant proportion of the variance (29%) in SF-36 physical functioning. Thus, in this multicenter study, the persons with FMS exhibited marked functional impairment, high levels of some lifetime and current psychiatric disorders, and significant current psychological distress. Current anxiety level appears to be an important correlate of functional impairment in individuals with FMS.

The neuropsychiatric sequelae of chronic Lyme disease remains unclear. This study sought to characterize the psychological status of a group of participants who met criteria for post-Lyme syndrome (PLS). These measures were then used to examine the influence of psychological status on neuropsychological performances. Thirty PLS participants completed a structured psychiatric interview, the Positive and Negative Affect Schedule, the Lyme Symptom Checklist, and a battery of neuropsychological tests. As a group, the PLS participants did not appear to have an elevated incidence of psychiatric disorders, and psychiatric history was not useful for understanding neuropsychological performances or symptom reports. The mood of the PLS participants was characterized by lowered levels of positive affect (PA) and typical levels of negative affect. This combination can be distinguished from depression and is consistent with previous findings of affect patterns in individuals with chronic fatigue syndrome. PA was also linked to both total symptom severity and severity of cognitive complaints, but not to duration of illness, neurological manifestations at initial diagnosis, or treatment history. Relative to published normative data, neuropsychological performances were not in the impaired range on any measure. Neither psychological status nor symptom report were useful for understanding any aspect of cognitive functioning. It is concluded that decreased PA is the most useful marker of psychological functioning in PLS.

Although several studies have suggested that cognitive slowing is a symptom in Lyme disease, it is not clear whether this slowing is general or relates to specific cognitive tasks. This study examined cognitive speed in 25 Lyme disease patients using a mental arithmetic task. These patients showed significant impairments when initiating the cognitive processes involved in counting, but performed as well as healthy participants (n = 23) when the number of counting increments increased. Lyme patients also performed a speeded perceptual-motor matching task as well as healthy participants. Lyme-related initiation speed deficits were significantly correlated with performance on standardized neuropsychological tests, including the Trail Making Test and the Digit Symbol Test, but not with self-reported depression. These results suggest that the cognitive deficits seen on speeded tasks are process specific in the Lyme patient group, and are not the result of generalized slowing.