If its for ptsd theres emdr. It's done with a therapist but you're basically making your brain do surgery on itself.

Not sure if you have a specific condition in mind. There are ways to help increase your overall happiness, but for psychology problems you should really consider therapy to fix the root of the problem. Doing your favorite hobbies boosts dopamine. Eating healthy, and making sure you’re getting enough vitamins and nutrients. Exercise if you’re able to, it releases endorphins and improves your overall health and energy. I would also cut out caffeine, or anything that upsets your body. For BP, meds and therapy are highly recommended. I’m not sure there are many other options. There are electrical-based medical procedures that have been shown to help treatment resistant mental illnesses, like vagus nerve stimulation and deep brain stimulation