Mice engineered to lack a specific gene showed behaviors similar to human mania in a study funded in part by NIMH; they were hyperactive, slept less, appeared less depressed and anxious, and craved sugar, cocaine and pleasure stimulation. The rodents’ behavior was more normal after lithium treatment or restoration of a functioning CLOCK protein, which the knocked-out gene codes for.
The article says this is similar to human mania, and it sounds like it’s similar enough to tell us useful stuff, although the mice don’t sound bipolar, just, as they say, behaving similarly to some aspects of manic humans.
The CLOCK protein is involved in circadian rhythms. And so here is some interesting stuff on circadian rhythms in bipolar disorder, and on how lithium works, from one of my favorite bipolar disorder sites, Jim Phelps’ Psych Education. Lots of science, lots of high-level information that isn’t very widely spread, and an excellent site for info on bipolar II in general and on anxiety in bipolar.