5-HT(1A) receptor binding in euthymic bipolar patients using positron emission tomography with [carbonyl-(11)C]WAY-100635.
BACKGROUND
This study was undertaken to examine whether brain 5-HT(1A) receptor binding is reduced in euthymic bipolar patients.


METHODS
Eight medicated euthymic bipolar patients and 8 healthy volunteers underwent positron emission tomography scanning using the selective 5-HT(1A) receptor radioligand [carbonyl-(11)C]WAY-100635.


RESULTS
No significant difference in global postsynaptic parametric binding potential (BP(ND)) was found between euthymic bipolar patients (mean + or - SD, 4.24 + or - 0.76) and healthy volunteers (mean + or - SD, 4.34 + or - 0.86). Ninety five percent Confidence Intervals for the difference in group mean global postsynaptic BP(ND) were -0.77 to 0.97. Analysis of regional BP(ND) did not reveal regional differences between patients and healthy controls.


CONCLUSIONS
The number of subjects studied was limited and all subjects were on medication.


CONCLUSIONS
In contrast to previous findings of reduced 5-HT(1A) receptor binding in untreated unipolar and bipolar depressed patients [Sargent, P.A., Kjaer, K.H., Bench, C.J., Rabiner, E.A., Messa, C., Meyer, J., Gunn, R.N., Grasby, P.M., Cowen, P.J., 2000. Brain serotonin1A receptor binding measured by positron emission tomography with [(11)C]WAY-100635: effects of depression and antidepressant treatment. Arch. Gen. Psychiatry 57, 174-180]; [Drevets, W.C., Frank, E., Price, J.C., Kupfer, D.J., Holt, D., Greer, P.J., Huang, Y., Gautier, C., Mathis, C., 1999. PET imaging of serotonin1A receptor binding in depression. Biol. Psychiatry 46, 1375-1387] and in recovered unipolar depressed patients [Bhagwagar, Z., Rabiner, E.A., Sargent, P.A., Grasby, P.M., Cowen, P.J., 2004. Persistent reduction in brain serotonin1A receptor binding in recovered depressed men measured by positron emission tomography with [(11)C]WAY-100635. Mol. Psychiatry 9, 386-92], this study found no difference in 5-HT(1A) receptor BP(ND) between medicated euthymic bipolar patients and healthy controls. Normal 5-HT(1A) receptor BP(ND) in these patients may be a result of drug treatment or could indicate that reduced 5-HT(1A) receptor binding is specific to the depressed state in bipolar patients.
Sargent
Peter A
PA
University Department of Psychiatry, Warneford Hospital, Oxford OX3 7JX, UK. peter.sargent@obmh.nhs.uk
Rabiner
Eugenii A
EA
Bhagwagar
Zubin
Z
Clark
Luke
L
Cowen
Philip
P
Goodwin
Guy M
GM
Grasby
Paul M
PM
D000328:Adult; D000367:Age Factors; D001921:Brain / Q000000981:diagnostic imaging*; D002250:Carbon Radioisotopes; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010879:Piperazines; D049268:Positron-Emission Tomography; D011725:Pyridines; D044282:Receptor, Serotonin, 5-HT1A / Q000032:analysis*; D012016:Reference Values; D012702:Serotonin Antagonists
D002250:Carbon Radioisotopes; D010879:Piperazines; D011725:Pyridines; D012702:Serotonin Antagonists; D044282:Receptor, Serotonin, 5-HT1A; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide