Platelet membrane phosphatidylinositol-4,5-bisphosphate alterations in bipolar disorder--evidence from a single case study

Psychiatry Res. 1997 Mar 24;69(2-3):197-202. doi: 10.1016/s0165-1781(96)03022-3.


Abnormalities in the cellular phosphatidylinositol (PI) pathway have been proposed to be implicated in the pathophysiology of bipolar disorder. A platelet model was used to study phosphatidylinositol-4,5-bisphosphate (PIP2) membrane values in a bipolar disorder patient in different mood states, in a single case study. The patient was studied unmedicated, initially in the euthymic and later in the manic states, and subsequently on lithium after remission of manic symptoms. The relative percentage of PIP2 in the platelet membranes increased with cycling from the euthymic into the manic state. After lithium treatment, PIP2 decreased, and was similar to the euthymic state. This study further demonstrates the feasibility of this method, as well as its applicability to longitudinal studies in bipolar disorder, and suggests promising directions for future research in this area.

Publication types

  • Case Reports
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Antidepressive Agents / therapeutic use
  • Bipolar Disorder / blood*
  • Bipolar Disorder / drug therapy
  • Blood Platelets / chemistry*
  • Cell Membrane / chemistry
  • Female
  • Humans
  • Lithium Carbonate / therapeutic use
  • Phosphatidylinositol 4,5-Diphosphate / blood*


  • Antidepressive Agents
  • Phosphatidylinositol 4,5-Diphosphate
  • Lithium Carbonate