PLATELET MEMBRANE PHOSPHATIDYLINOSITOL-4,5-BISPHOSPHATE ALTERATIONS IN BIPOLAR DISORDER - EVIDENCE FROM A SINGLE-CASE STUDY

Abnormalities in the cellular phosphatidylinositol (PI) pathway have b een proposed to be implicated in the pathophysiology of bipolar disord er. A platelet model was used to study phosphatidylinositol-4,5-bispho sphate (PIP2) membrane values in a bipolar disorder patient in differe nt mood states, in a single case study. The patient was studied unmedi cated, initially in the euthymic and later in the manic states, and su bsequently on lithium after remission of manic symptoms. The relative percentage of PIP2 in the platelet membranes increased with cycling fr om the euthymic into the manic state. After lithium treatment, PIP2 de creased, and was similar to the euthymic state. This study further dem onstrates the feasibility of this method, as well as its applicability to longitudinal studies in bipolar disorder, and suggests promising d irections for future research in this area. (C) 1997 Elsevier Science Ireland Ltd.