Angelman syndrome is a genetic neurodevelopmental disorder. A common anti-cancer drug was found to turn a gene back on that is turned off in the syndrome. Huge breakthrough. If it pans out in humans I predict it will garner the Nobel in medicine/physiology.

http://www.nature.com/news/a-wake-up...t-genes-1.9700

There are obvious parallels with IS in terms of being a genetic disorder though it seems much more complex that just having one gene turned off. Anyway, the point stands that a drug can potentially help with genetic disorders. Actually, if bipolar is genetic then we already know a drug (lithium) can help with that so this wouldn't be breaking new ground in that respect. The new ground appears to be explicitly using a drug to turn on a silenced gened.