Posted on 03/21/2008 12:36:18 AM PDT by neverdem
Not everyone is vulnerable to post-traumatic stress disorder (PTSD)--the extreme anxiety, depression, and nightmares that can follow a harrowing event. Although some people develop symptoms after seemingly minor traumas, others can handle wars, hurricanes, or various forms of physical abuse without losing their emotional balance. Now, researchers have shown that mutations in a stress-related gene may help determine whether someone who suffered from abuse as a child is susceptible to PTSD later in life.
Teasing out the genetics of PTSD has been difficult. Children who are abused are more susceptible to PTSD as adults, and researchers estimate that up to 40% of this susceptibility is inherited. But just what genes are responsible is not known. One promising lead is FKBP5, a gene that helps regulate binding between stress hormones and their receptors. Research has shown that childhood abuse can lead to overreactivity in the body's stress response system, so a team at Emory University in Atlanta, Georgia, decided to see if there was a link between PTSD and mutations in FKBP5.
The researchers collected data on 762 people, most of them from poor black neighborhoods, who came to the clinic over a 2-year period for nonpsychiatric reasons. Through interviews and questionnaires, the subjects reported experiences with childhood abuse as well as other types of trauma in later life. Clinicians determined whether such traumas had triggered PTSD in adulthood. Subjects also gave saliva samples so their DNA could be tested.
Some 30% of the patients reported physical or sexual abuse, or both, as a child. This group showed twice the number of PTSD symptoms following later traumas, such as an accident or robbery, as those who had not reported being abused. And the prevalence of two particular mutations in the FKBP5 gene were significantly more common in this abused group among those who had PTSD than those who did not. The mutations by themselves do not predict PTSD, showing that it's the combination of certain genes with the early trauma that leads to the vulnerability. The researchers theorize that some of the mutations make brain cells in children more sensitive to stress hormones throughout their lives.
The findings, reported today in the Journal of the American Medical Association, are complex and preliminary but "biologically plausible," says Richie Poulton of the University of Otago in Dunedin, New Zealand, an expert on gene-environment interactions. It's an "important paper," adds psychiatrist Daniel Weinberger of the National Institute of Mental Health in Bethesda, Maryland. The work is part of an emerging body of research "showing that genes for complex psychiatric conditions are best studied in the context of other risk factors," he says. "I think this is the wave of the future."
Related sites
Current Issue: Vol. 299, No. 11, March 19, 2008. Theme Issue: Genetics/Genomics
There are a number of FReebies in JAMA.
JAMA?
What’s wrong with JAMA?
thanks so much for posting
PTSD?I guess now they can start disarming earlier.
Very interesting. One of my close friends and a colleague has been doing research on susceptibility to PTSD and he told me that having a Dx of personality disorder (of the lively and dramatic type) was a common finding for PTSD patients. My clinical experience supports this as well.
Bump for narcissists and borderlines!
If spanking is considered child abuse by the AMA, and child abuse increases the risk of PTSD, is now anyone who was spanked at risk of PTSD, so we need to take guns away from them?
This is one of the few areas of study that makes me wish I could live (and keep my marbles) for another 50 years. In my amateur pastoral/counseling experience (characterized as often as not by trying to help people into getting psychiatric help) I see a kind of gradation of personality disorders and their manifestations.
I mean some sufferers manage to make it through life with moderately successful careers, staying out of jail, no kids in jail, marriages intact, like that. Others are chronically at odds with life. Both groups have "episodes" when they come unwrapped, maybe end up in court or in jail, maybe just alienate some friends or end some relationships.
In the families of these people I see relationships, dynamics, and adaptations strikingly (to me) similar to what you see in alcoholic families.
I have real trouble teasing out what's genetic and what's situational, but I really like the idea that childhood stress can flip one into a style of reacting that then characterizes the rest of one's life.
I began to think of this as a "habit" or a conditioned reflex and surmised that for many milder PD types learning to react and cope in "healthy" ways would be a lot like UNlearning how to ride a bike. That is, it would be REALLY hard and with a crappy prognosis -- and that the KIND of thing that is the most likely to help would be something like AA - or some kind of group work lasting for a decade or longer, if not for the rest of the sufferer's life.
ANd of course a big problem there is that unless somebody has things like the grosser manifestations of PTSD, one is not going to enter into such Rx because, after all, "It's not MY problem, it's (their/your) problem." (And (they/we) frequently DO have a "problem" arising from being in some kind of relationship with the sufferer -- and in families frequently the "presenting Member" is not the sickest.
Comments would be appreciated. All this is from thinking hard about people to whom I have "ministered" (though not in the BJ Clinton sense) over the past 3 decades.
In other words, some people are just liberal p*ssies
Eh, I’m not buying it. I’m not borderline, not dramatic or narcissistic, and I never experienced childhood sexual or physical abuse. Neither have my children. But my kids and I developed a case of PTSD after a terrible experience we had.
Also, as part of my work I have examined the medical and psychiatric records of several hundred veterans with PTSD. I can’t recall even one of them being labelled narcissistic or dramatic. On the contrary. Admittedly some of them might have been borderline—I recall a couple of female veterans who had borderline personality disorder of various sorts.
I don’t think that a PD in the background would be necessary for PTSD to show up later. But it might lower the threshold.
The study might have discovered correlation, not causation. In other words, the personality disorders or history of abuse might not increase the likelihood of PTSD showing up because of some genetic anomaly. There could be two other mechanisms at play here:
1. First, people from an inner-city, black, poor background might by definition be more likely to experience events that would legitimately cause PTSD (being shot, being victim of a serious crime, being threatened, etc.) and might have less access to excellent psychiatric care than someone who lives in a better place.
Second, PD or history of abuse, rather than predisposing the patient to PTSD, might instead prevent the patient from recovering from what would for the average person a very transient case of PTSD.
Just a thought. But you could find 47 things wrong with the design of this study and its conclusions.
“In other words, some people are just liberal p*ssies”
—nice! just in time for Good Friday!
>>is now anyone who was spanked at risk of PTSD,
>>so we need to take guns away from them?
That would seem to be consistent with their MO.
I don’t know what JAMA is.
Click the link. It won't bite you. I promise.
So do I and I think in many ways the nature-nurture "issue" is a false dichotomy. The role of learning is very powerful; and the quest for a medical model of psychiatry (e.g., the pursuit of the psychopathogene) is more as not a case of medical economics' control over a healing discipline.
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