There is a common belief in the anti-cult movement that ex-members of cults should seek for psychological counseling or therapy and better if this counseling/therapy is provided by mental health professionals who are knowledgeable about cult issues.
It looks quite logical, but there is one problem. There are no independent studies that indicate that it is so. There are probably millions people who left cults and most of them have never went to therapists who counsel ex-members of cults. Most of them probably do not know that they "should" do that. Who can say that they are in a worse position than those who go to therapists for years? I know some ex-members of my former cult (and some of them were very seriously abused by it) who have never contacted the secular anti-cult movement and did not seek therapy after their leaving, but who have very happy and fulfilling life now.
So, there are no independent data that indicate that ex-members of cults need therapy. Well, of course, therapists who counsel ex-cult members often say that it is very important for them to get therapy, but do not forget that these therapists earn money from counseling ex-members of cults. Also, some people who were counseled say that they got help, but it is quite subjective and not all of the people who were counseled are satisfied with their therapists. When people believe that therapists help them, it is very easy for them to feel better regardless of whether they really get help from the therapy or not. In medicine, there is a famous placebo effect: when people believe that a certain pill is a very effective medicine, many of them will feel better, even if this pill is absolutely useless. Of course, placebo effect exists in psychotherapy as well. And, as I wrote, there are no independent studies that therapy for the post-cult recovery really helps.
In 1952, H. J. Eysenck published his classic study (http://psychclassics.yorku.ca/Eysenck/psychotherapy.htm) where the main conclusion was that psychotherapy does not affect people's recovery from psychological disorders: whether people undergo therapy or not, the result will be the same. This study sparked a lot of controversy, and there have been many attempts to disprove this study, but they do not look very satisfactory to me. I know that there are many cases when researchers publish studies that indicate that certain psychotherapies do not help or even harm, people who practice them try to disprove these studies. Of course, people who practice such therapies (whether they are really harmful or not) are unhappy that someone criticizes them, but this reaction itself does not mean that the researchers wrong when they say that these therapies are harmful. I think it is a very similar situation with Eysenck's study. If any psychotherapy is useless, than, it means that all the practicing psychologists, psychotherapists, and all the other mental health professionals should close their practices and seek for another job. But do they want it? Of course, not.
So, Eysenck's study indicated that any psychotherapy is useless for treating psychological disorders. And there are no independent studies that indicate that psychotherapy has any benefit for ex-members of cults.
There is another problem. There are some "popular" diagnoses that are often given to ex-members of cults, such as PTSD, C-PTSD, and DID (or DD NOS). Some of these diagnoses are very controversial by themselves. C-PTSD has never been considered as a valid diagnosis by DSM. DID is also a very controversial diagnosis (even when it is not applied for ex-members of cults). Moreover, DSM does not say anything about cults or disorders that have been caused by cults.
There are some mental health professionals who prefer not to give any diagnoses. Well, I do not think that is is better. Suppose, you go to a medical doctor and he or she does not give you any diagnosis. What does it mean? Usually, it means that: (1) either you are healthy and do not need any medical aid or (2) he or she does not know what is the problem with you and how to treat you. In either case, you will probably not go to this doctor for treatment. But why should anyone go to a therapist who does not give any diagnosis?
Another point is that probably there are no two mental health professionals who counsel ex-members of cults who would agree with one another. They disagree on, practically, everything: on the definition of a cult and what groups are cults and what are not; on the definition of cult mind control (thought reform or whatever other term is used); on the definition of post-cult recovery; on what therapy is more helpful for ex-members of cults; and on many other things. In this diversity of opinions, who is right and who is wrong? Probably, no one is right. And, actually, this diversity of opinions just shows that the whole secular anti-cult field is far too subjective.
Well, I like to say that I have never been under psychotherapy (including therapy for post-cult recovery) and have never needed it. But who can prove that it is an exception and not the rule? And who has ever proven that ex-members of cults need therapy? No one.