I would tell them to go away from whatever place they are at for a moment, go to another city, countryside, or even another continent and read Buddha. While it is not a quick fix in form of aspirin for their headache, the knowledge they learn from his teachings will show them how to never get a headache ever again. But to be able to focus on it, once must find a place which doesn't distract him and provides him with peace. Somewhere where you have no business to do. So you can just be.

Although I understand and can confirm from my personal experience, that nobody fully understands what he reads for the first time, until he goes all the way round and ends up where he started.

It's like, you get your first book, and it will give you ideas, then you'll go and may read thousand other books you have been inspired to read only to come back to the one you got at the beginning and then you'll understand it better. Then you go another round, and when you come back you understand it even deeper. Same words, same sentences, same book. Yet it still provide more and more knowledge.

It is because of the spiral of awareness. The more you know the more your awareness raises, which causes your perception to change, which leads to seeing more than you saw before.

But yea, I would start with Buddha definitely.

Have candy. Just the offering of something sweet is a good key into someone that is need of advice,hard candy or a toffee. It is often associated with better times. Then look for things to be grateful about no matter how small or insignificant. Remember or have The Abraham-Hicks Emotional Guidance Scale
The person probably will not go from 12. Disappointment to 3. Enthusiasm/Eagerness/Happiness in one step
peace