A new way of thinking about PTSD

Photo by Mary Knox Merrill.

Clin­i­cians diag­nose Post Trau­matic Stress Dis­order, or PTSD, based on a series of cri­teria. An impor­tant one of these states that PTSD comes about after someone expe­ri­ences “intense fear, help­less­ness or horror” in response to a trau­matic event. One pop­ular theory of PTSD is that the amyg­dala, as the brain seat of fear, is not reg­u­lated well.

I have a vision of psy­chology pro­fessor Lisa Feldman Bar­rett sit­ting at her desk reading that line in the Diag­nostic and Sta­tis­tical Manual of Mental Dis­or­ders and slap­ping her fore­head in frus­tra­tion. Bar­rett has spent the last decade pushing against the com­monly held idea that emo­tions are local­ized to par­tic­ular areas of the brain and that they are the sort of “sub­atomic par­ti­cles” of psychology.

Despite tons of evi­dence that the amyg­dala is active in all sorts of emo­tional responses, from fear to anger to sad­ness, as well in social pro­cessing and vision more broadly, and it is still widely believed to be the “fear” area of the brain. And since PTSD is thought to be a “fear dis­order,” clin­i­cians and some sci­en­tists think it is a dis­order of the amyg­dala, too.

In an article pub­lished last year — which was the most down­loaded from the Journal of Trau­matic Stress in 2011 — Bar­rett and her col­league Michael Suvak, a PTSD expert at the VA Boston Health­care System, apply what Bar­rett calls a “con­struc­tionist approach” to under­standing the disorder.

The psy­cho­log­ical con­struc­tion approach pro­poses that phe­nomena like emo­tions, cog­ni­tion and per­cep­tion are not the fun­da­mental ele­ments of the mind, asso­ci­ated with dis­tinct brain regions. Instead, the authors write in the article, they “are the names people give to mental events that result from the inter­play of a more basic, common set of psy­cho­log­ical ingre­di­ents.” These ingre­di­ents, they hypoth­e­size, are net­works of brain activity that cor­re­spond to things like affect, con­cep­tu­al­iza­tion, and exec­u­tive function.

Instead of labeling PTSD as a “fear dis­order,” the sought-​​after paper sug­gests it might be more useful to think of it as a dis­order of one or more of these func­tional net­works. For example, it could be that for people who develop PTSD “infor­ma­tion from the world has stronger affec­tive value,” say the authors. “It is more moti­va­tion­ally salient and home­o­sta­t­i­cally rel­e­vant, even when it ought not to be.”

Looking at PTSD from this per­spec­tive resolves some of the long-​​considered mys­teries about the dis­order, namely that an indi­vidual can develop PTSD without expe­ri­encing the emo­tions of “fear” and “anx­iety” and that mul­tiple brain regions seem to be hyper– or hypo-​​active in PTSD indi­vid­uals, not just the amygdala.

With PTSD gaining more atten­tion in the media, in society and in the research world, under­standing the dis­order at its roots will be of par­tic­ular importance.