Objective: To evaluate the prevalence and role of psychiatric comorbidity and other psychological factors in patients with chronic Lyme disease (CLD).
Methods: We assessed 159 patients drawn from a cohort of 240 patients evaluated at an academic Lyme disease referral center. Patients were screened for common axis I psychiatric disorders (e.g., depressive and anxiety disorders); structured clinical interviews confirmed diagnoses. Axis II personality disorders, functional status, and traits like negative and positive affect and pain catastrophizing were also evaluated. A physician blind to psychiatric assessment results performed a medical evaluation.
Two groups of CLD patients (those with post-Lyme disease syndrome and those with medically unexplained symptoms attributed to Lyme disease but without Borrelia burgdorferi infection) were compared with 2 groups of patients without CLD (patients recovered from Lyme disease and those with an identifiable medical condition explaining symptoms attributed to Lyme disease).
Results: After adjusting for age and sex:
• Axis I psychiatric disorders were more common in CLD patients than in comparison patients (P = 0.02, odds ratio 2.64, 95% confidence interval 1.30-5.35), but personality disorders were not.
• Patients with CLD had higher negative affect, lower positive affect, and a greater tendency to catastrophize pain (P < 0.001) than comparison patients.
• All psychological factors except personality disorders were related to level of functioning. A predictive model based on these psychological variables was confirmed.
• Fibromyalgia was diagnosed in 46.8% of CLD patients.
Conclusion: Psychiatric comorbidity and other psychological factors distinguished CLD patients from other patients commonly seen in Lyme disease referral centers, and were related to poor functional outcomes.
Source: Arthritis and Rheumatism, Nov 26, 2008; 59(12):1742-1749. PMID: 19035409, by Hassett AL, Radvanski DC, Buyske S, Savage SV, Gara M, Escobar JI, Sigal LH. University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick; Rutgers University, Piscataway; Bristol-Myers Squibb, Princeton, New Jersey, USA. [E-email: