Do Jehovah's Witnesses have a higher rate of mental illness among their members or those who leave the organization as some claim? There is no published, peer-reviewed information conclusively demonstrating a higher rate of mental disorders or distress among Jehovah's Witnesses. Though there have been articles purporting to be "studies" that claim a high rate of mental disorders among Jehovah's Witnesses, but with no independent support.
In one article I found on the subject*, they gave no conclusive evidence and tried to make the positive statements made by one of only three studies it quotes look like negative statements where the study concluded that there was no reason to restrict Jehovah's Witness parents from raising children and espousing their beliefs to them. In fact, the study cited really wasn't about the prevalence of mental illness among Jehovah's Witnesses at all, but about whether Jehovah's Witnesses were fit parents. The second "study" it cited, rather just an article that claimed a high rate of mental illness among Jehovah's Witnesses without support, was claiming that a parent does not have a right to bring their child up in a limited view of the world. It didn't make any statistical claims regarding mental dysfunction among Jehovah's Witnesses at all. And the third of the three studies cited was so loaded with emotionally-laden words and vile disdain for Jehovah's Witnesses in general and their beliefs, showing a clear bias, that no scientist would give it any credence, so its unsupported conclusions could not be trusted in any sense.
The other studies the article mentioned, it summarized for the reader without references or quotations from the studies. These included mental health studies done by Swedish and U.S. militaries, in 1946 and 1949 respectively and another U.S. military Study from 1972 to 1976, these studies acquiring most of their information before drafting was done away with regarding Jehovah's Witnesses as conscientious objectors, claiming a high degree of mental illness; not exactly unbiased, especially when you consider the attitudes of the military against conscientious objectors in those days.
In fact, those three studies from militaries constitute the full extent of mental illness studies, which amount to "anyone that objects to the military is a nut case". The first three studies, those the article quoted, did not provide any information regarding mental disorders among Jehovah's Witnesses at all. The article also seems to suggest that "disillusionment" is a mental disorder. At the end of the article, it concludes with an admission that there just wasn't enough information to claim a higher rate of mental disorder among Jehovah's Witnesses. So the article trying to claim it ends up concluding otherwise.
In The Mental Health of Jehovah's Witnesses, by John Spencer, Mr. Spencer gives a clear indication of bias, giving commentary about the legitimacy of Jehovah's Witness beliefs and stating that because it differs from orthodoxy, that the terms "psychotic" and "paranoid" would best be applied. Due to this bias, an impartial scientist would never give any credence to such consideration and would disregard the entire article on such grounds, and rightfully so.
In the publication, Social Compass, Vol. XXIV, 1977/1, Havor Montegue, in The Pessimistic Sects Influence on the Mental Health of its Members: the Case of Jehovah's Witnesses, claims a low value of life and a high murder rate among Jehovah's Witnesses without providing any supporting evidence to the claim. Despite providing a seemingly unbiased tone, Montegue goes on to use John Spencer's article above as his primary source of information, though itself is not an actual "study". So clearly, Montegue does not give consideration to the bias demonstrated by the articles he researches, nor does he rely impartially upon actual studies.
Ultimately, all the information in these articles all go back to the three biased studies done by the U.S. military concerning conscientious objectors. The conclusions of the majority amounts to 'religiosity is insanity; Jehovah's Witnesses are devoutly religious, therefore they are rife with mental illness.'
Though a claim was made by the above psychiatrist that there was a higher rate of suicidal inclinations, no support was given suggesting a higher rate of suicide among active members, though he tried very hard to imply it while dodging any actual claim to such.
I found one article done about the relationship between Jehovah's Witnesses and Schizophrenia by Michael Rand. In the article, he repeatedly refers to studies that make generalizations about belief systems and religion, as well as about immigrants, but make no direct connections to Jehovah's Witnesses. Instead, his article makes generalizations about Jehovah's Witnesses in an effort to confirm pre-existing biases and conclusions with studies that did not focus on Jehovah's Witnesses at all, despite his claims otherwise. In fact, the very purpose of his article is, "The hypothesis is that the practices and beliefs expressed by the Jehovah's Witnesses can be associated with the Schizophrenic Migration model by Drs. Selten, Cantor-Graae, & Kahn (Selten, Cantor-Graae, & Kahn, 2007) which could result in a higher risk of schizophrenia." That is, his intent is not to prove that Jehovah's Witnesses have a higher rate of schizophrenia, but that "Jehovah's Witnesses can be associated with" the article by Drs. Selten, Cantor-Graae and Kahn.
The article goes on to directly claim a distrust by Jehovah's Witnesses of psychological professions, yet, this is countered by the many articles by Jehovah's Witnesses on depression that very clearly recommend professional help if immediate resolution through application of Bible principles cannot be obtained. The article goes on to speculate about what Jehovah's Witnesses "might" or "may" believe regarding psychological professions, but gives no testimonial or study evidence. Thus, the article has a very clear bias against Jehovah's Witnesses.
The article claims without support, "This is compounded by the fact that Jehovah's Witnesses do not care for their own mental health often because they feel that Armageddon is just around the corner and as such it won't matter." It then states, "The solution to this issue is the same as it would be with any group of people: simply attempt to foster trust and understanding in order to achieve common ground." Yet the article it cites for support has nothing to do with Jehovah's Witnesses. Thus, it is an assumption, as all the studies cited in the article are applied in the same way, though none of the articles ever refer to Jehovah's Witnesses. It simply tries to claim that Jehovah's Witnesses are like immigrants and are therefore affected by the same issues as immigrants. In reality, Michael Rand was, in fact, just a student at Walden University. The article is not actually endorsed by the University, nor is Michael actually a psychiatrist or psychologist.
But if these attempts at studies of mental illness among Jehovah's Witnesses were intent upon finding actual facts, they would abandon biases against doctrines, avoid poisoned wells and stick to impartial data from random sampling and careful research. Since the people performing these studies are incapable of being impartial, scientific and thorough, clearly there is no reason to give any credence to their efforts, no matter how monumental. Twisting a fact to suit one's agenda does not make it a new fact; it just turns it into a lie.
* It was an article apparently written by an apostate. I do not give referrals to such articles.