A STICKY INTERHEMISPHERIC SWITCH IN BIPOLAR DISORDER

Citation
Jd. Pettigrew et Sm. Miller, A STICKY INTERHEMISPHERIC SWITCH IN BIPOLAR DISORDER, Proceedings - Royal Society. Biological Sciences, 265(1411), 1998, pp. 2141-2148
Citations number
59
Categorie Soggetti
Biology
ISSN journal
09628452
Volume
265
Issue
1411
Year of publication
1998
Pages
2141 - 2148
Database
ISI
SICI code
0962-8452(1998)265:1411<2141:ASISIB>2.0.ZU;2-J
Abstract
Despite years of research into bipolar disorder (manic depression), it s underlying pathophysiology remains elusive. It is widely acknowledge d that the disorder is strongly heritable, but the genetics are comple x with less than full concordance in monozygotic twins and at least fo ur susceptibility loci identified. We propose that bipolar disorder is the result of a. genetic propensity for slow interhemispheric switchi ng mechanisms that become 'stuck' in one or the other state. Because s low switches are also 'sticky' when compared with fast switches, the c linical manifestations of bipolar disorder may be explained by hemisph eric activation being 'stuck' on the left (mania) or on the right (dep ression). Support for this 'sticky' interhemispheric switching hypothe sis stems from our recent observation that the rate of perceptual alte rnation in binocular rivalry is slow in euthymic subjects with bipolar disorder (n=18, median=0.27 Hz) compared with normal controls (n=4-9, median=0.60 Hz, p<0.0005). We have presented evidence elsewhere that binocular rivalry is itself an interhemispheric switching phenomenon. The rivalry alternation rate (putative interhemispheric switch rate) i s robust in a given individual, with a test-retest correlation of more than 0.8, making it suitable for genetic studies. The interhemispheri c switch rate may provide a trait-dependent biological marker for bipo lar disorder.