The relationship of subsyndromal depression to syndromal depression is unclear. Increased sensitivity of platelet serotonin type 2 receptor has been reported in depression using the Fura-2 technique. The sensitivity of the platelet serotonin type 2 receptor was assessed using the Fura-2 method in 16 patients with subsyndromal depression and 14 controls. The patient group had higher numerical values of both basal and serotonin-stimulated levels of platelet intracellular calcium that did not however reach statistical significance.