Markers of thrombogenesis are activated in unmedicated patients with acute psychosis: a matched case control study

Background: Antipsychotic treatment has been repeatedly found to be associated with an increased risk for venous thromboembolism in schizophrenia. The extent to which the propensity for venous thromboembolism is linked to antipsychotic medication alone or psychosis itself is unclear. The objective of this study was to determine whether markers of thrombogenesis are increased in psychotic patients who have not yet been treated with antipsychotic medication. Methods: We investigated the plasma levels of markers indicating activation of coagulation (D-dimers and Factor VIII) and platelets (soluble P-selectin, sP-selectin) in an antipsychotic-naive group of fourteen men and eleven women with acute psychosis (age 29.1 +/- 8.3 years, body mass index 23.6 +/- 4.7), and twenty-five healthy volunteers were matched for age, gender and body mass index. Results: D-dimers (median 0.38 versus 0.19 mg/l, mean 1.12 +/- 2.38 versus 0.28 +/- 0.3 mg/l; P = 0.003) and sP-selectin (median 204.1 versus 112.4 ng/ml, mean 209.9 +/- 124 versus 124.1 +/- 32; P = 0.0005) plasma levels were significantly increased in the group of patients with acute psychosis as compared with healthy volunteers. We found a trend (median 148% versus 110%, mean 160 +/- 72.5 versus 123 +/- 62.5; P = 0.062) of increased plasma levels of factor VIII in psychotic patients as compared with healthy volunteers. Conclusions: The results suggest that at least a part of venous thromboembolic events in patients with acute psychosis may be induced by pathogenic mechanisms related to psychosis rather than by antipsychotic treatment. Finding an exact cause for venous thromboembolism in psychotic patients is necessary for its effective treatment and prevention.