I don't know whether or not being a JW causes psychological problems, but it can make existing issues much, much worse. In my case, I didn't realize how much the experience had damaged me until recently, and I've been out for almost four years now.
When I first started studying with the Witnesses, I was 17. I've always wanted to do "the right thing," whatever that entailed, I've always been spiritual (i.e. wanted to make God happy), and I've always been a bit shy. I really wanted a place to belong, and the chance to believe I was making God happy. The Witnesses gave me that. But later on, I realized that my life among them was... wrong. Much of what I'd been taught to believe just didn't make any sense and/or nagged at my conscience, and besides that, a part of me that just wanted to grow up.
I ended up leaving. A lot of things happened -- some good, some bad, some indifferent, much to do with the self-discovery that I hadn't realized I'd been denied in my late teens and early twenties. I came to realize that, in a lot of ways, my psychological development had been frozen at age 17, the age I was when I first hooked up with the Witnesses. And since my entire social life had been among JWs then, I never learned how to make friends in the "real world", and all the friends I might've made in college were gone. So, over time, my shyness problems have become progressively worse while I wasn't looking. Right now, I have no real life friends because I don't know how to connect with them. I assume they wouldn't be interested and just save us both the trouble.
Looking within myself, though, I've reached another conclusion: the things I was taught as a Witness helped my make my present shyness worse. All that stuff about thinking no more of yourself than necessary, putting everyone else (especially the Org) above yourself, not giving too much attention to your own needs, that sort of thing.... It really stuck with me since my self-esteem wasn't so terrific to begin with. I took those things to heart, and somewhere deep down, I concluded that I wasn't worthy of genuine love. I was supposed to give everything; I had no right to want or expect anything in return.
And on top of that, I know I still had that same old tape playing, always there but made all the louder by my past experiences: never tell anyone all of your secrets, never reveal who you really are or what you really think. Otherwise, it might be used against you.
And, of course, that isn't healthy.
I've made an appointment with a therapist to help me live more fully. I realize now that I can't do this alone. And don't even get me started on the isses I had with depression which started while I was still "in." I know I'm not the only one who's had problems like these.
~Rochelle.