Medication-Based Disadvantage Changes

[Ecstatic Savant]

Greetings all, I have a question for the more experienced players and GMs out there. I have a campaign I'm putting together where one player was afflicted with Berserk and a handful of other similar disadvantages from a god-like entity. The actual way these disadvantages affect his brain is largely physical, though, so it can be somewhat controlled with medication. The medication in question would replace most of his hot-tempered disadvantages with counterparts that make him more reserved and restrained, like Incurious and Clueless. My question is, what would be the best way to represent that shift in his character? I initially considered mitigation on the appropriate violent disadvantages, but that would just remove them entirely while under the effects of the medication. Split Personality was my second idea, but it doesn't really seem applicable given the circumstances. I'm kinda stumped on this one and any help would be greatly appreciated.