So let me narrow it down a bit: Does one need therapy when one is on the spiritual path? So, here is my perspective on this: therapy, fundamentally, improves functionality. If you are fully functioning, or functioning as needed for and required for you and your life, there is no need for therapy, or repair of your machine, of any kind.
In my experience and that of many others many others I know, being on the spiritual path will bring up, or forth, states and trauma and wounding which prior to that you were not conscious of, but which expressed as habitual postures and actions in your life.. Those states can be very difficult to deal with and in fact make you dysfunctional, and at some point or another everyone needed some kind of help to move forward. I recently listened to an introduction for a course and it was advised: if you are in any way unstable mentally, we recommend you NOT take this course. Some schools, such as the BBSH, will not even allow you to attend unless you are in therapy, and here is why: when those difficult times and states arise, it is not appropriate to lay it on your family, friends, teachers and coworkers to have to deal with them. You need reliable, competent help to help you through it and if possible, stay functional. Falling apart, loosing it, not being able to get grounded, starting to open to high sense perception - all that can be very difficult and frightening to deal with - even though is is to be expected. Some spiritual schools have a system set up whereby you are obligated to have peer student support contacts as well as teacher sessions, which are properly boundaried and which you pay for. Some schools will do a certain level of ministering as part of service, but if you ever hear any suggestion at all that maybe professional help is needed: that is a big hint. If you are lucky, you can continue through the waves with sheer will or apply the principle of borrowing necessity to function - for something higher than you. Transformation can happen that way too. Point is: one way or another YOU are responsible to deal with it
So in short, chances are, at some point or another you on the spiritual path will find yourself in need of help to deal with stuff, whatever your perception is of how that came about. Stuff IS going to come up. That is when you find ways to handle it adequately on yuor own, without becoming dysfunctional, or find a helper or therapist, you can trust. It may be for a few weeks, or a few years. You find a way to deal with whatever it is that comes up without forcing friends and family into a role they really should not be burdened with. Find compatriots on the path to compare notes with and get professional help when necessary
I have explored a few non conventional therapies and was and am delighted about what I found out there.