Flooding tha brain with serotonin and dopamine are the solution, but the problem is that most of medications are reuptake inhibitors. They doesn't work for many people and have horrible side effects.
Aripiprazole is helping my brother after several months of anhedonia and depression. The usual antidepressants and mood stabilizer didn't help much. Although, this all came after a psychotic break and there is a suspicion that he suffers from bipolar or schizoaffective, so not sure it applies. Sulpiride also seems to be helping my father somewhat, for years he had been on quetiapine.