The objective of the study was to evaluate the presence of psychopathology in fibromyalgia patients compared to a control group of rheumatic patients with pain. Forty-nine fibromyalgia patients and 33 controls were evaluated using established self-rating scales. Serotonin was determined using a radioenzymatic method. Fibromyalgia patients scored significantly higher than the controls on the majority of the subscales on the SCL-90, the two subscales on the Spielberger State and Trait Anxiety Inventory, the GHQ 12 scale and on a visual analogue pain scale. In a multivariate analysis the somatization dimension followed by the state anxiety accounted for the highest difference. Platelet-poor plasma serotonin, platelet serotonin and platelet uptake index were not significantly different between the groups. In conclusion, fibromyalgia patients presented quantitatively more psychopathology than the control group on a wide range of psychopathologic axes, and this cannot solely be accounted for by their higher level of pain.
