Licensed therapists have to conform to a recognized standard in ethics and methods around psychotherapy. There are then different types of specialties/theories that build atop that base framework.

Psychology (like medicine and computer-science) is an ever evolving science. Just 50 years ago, we would try to shock the depression out of you - and it worked for a short period of time.

We haven't reached the final say in how the mind works, or who we are, and we probably never will, but every year we get closer.

Electroconvulsive therapy is still in use on patients that do not react to other treatments. Patients are anesthetized and the doses have been lowered today though.

https://www.mayoclinic.org/tests-procedures/electroconvulsiv...

It's always be a very effective method for some mental health issues. It's just dangerous (it affects more than what you are targeting), and should always be a last resort (which it is now).

In the past it was the first or second answer to a LOT of illnesses from the made up (hysteria - read: horny wife and inexplicable weight gain) to the legitimate (depression, hyperactivity, bipolar disorders).