Antipsychotics work with a specific regulated effect. It can't be done naturally. Right now they are actually researching antipsychotics that go beyond the dopamine hypothesis. The antipsychotic agent I take that is in Phase II FDA study works on a totally new hypothesis that is that it regulates glutamate transmission and that class of antipsychotic once FDA approved (the NMDA receptor modulates, google "Dr. Javitt, glycine") is showing much promise regarding safety and efficacy and in myself has promoted a full recovery but just like the current generation of antipsychotics has a specific targeted effect. Only medications can change the way receptors of neurotransmitters work in the brain.
Exercise. A lot of research suggests that proper exercise is the best way to regain your mental health.
Take plants as an example (I know that it's a cheap example, but it makes a point): If you cut a leaf off a plant, the best way to make it grow out again is to give the plant plenty of sun, water and oxygen.
The same can be said about a human. If you get enough exercise, sun, water and clean air, your health should improve. Physically and mentally.