Therapy is all about learning how to cope and manage difficult situations better, but sessions may not always equip patients with the practical tools they need to face challenges when they occur.
In fact, the latest research suggests that just when self-control is critical—such as during frightening or traumatic situations— stress impairs the parts of the brain that are essential for staying rational. That means that cognitive behavioral therapy (CBT) — the most effective talk therapy for treating anxiety disorders and depression — can fail patients just when they need these coping skills the most.
“The study is a thought-provoking and surprisingly simple demonstration of a possibly very common and crucial everyday limitation on cognitive restructuring techniques, like those learned in CBT,” says Keith Laws, professor of psychology at the University of Hertfordshire in England, who was not associated with the research.
The study’s 78 healthy participants, none of whom had previous phobias or anxiety disorders, were trained to fear images of spiders or snakes with mild electric shocks. After several training sessions, they all displayed fear of the shocks when the appropriate images flashed on a screen — measured by their own descriptions of their emotions as well as by changes in their skin’s ability to conduct electricity when aroused. The participants were then taught CBT techniques to manage their emotions.
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The coping strategies helped the participants to recognize how their thoughts influenced their feelings — and helped them to reframe the fearful experience to lessen the impact of negative thinking. So, for example, rather than anticipating the pain of the shocks and worrying about how long they would last, they were instructed to distract themselves and view the experience as an annoyance, not an ordeal. “The idea is that the way you choose to see the situation can alter your response,” says study co-author Elizabeth Phelps, professor of psychology at New York University.
That’s the way CBT is supposed to work, and hundreds of studies have documented that teaching people how to tap into these skills can help fight anxiety disorders and depression.
But CBT doesn’t work for all people, or in all situations — and Phelps may have found a good reason for why. She brought the participants back to the lab the day after their CBT training to see whether the techniques they learned would stick. To create stress, she had half of the group submerge their right hands in ice water for three minutes — which raised stress hormone levels. The rest of the participants held their hands in tepid water for the same time.
Ten minutes later, all were confronted with the images that they knew would be followed by shocks— but only the non-stressed group showed less fear than they did in the initial experiment. Indeed, the stressed group was just as frightened as they had been before they learned CBT, meaning that the stress— in the form of the ice bath— had rendered the therapy useless.
“What we think is happening is that even mild stress can lead to subtle deficits in [the functioning of] the prefrontal cortex (PFC),” says Phelps, referring to the brain area responsible for control over emotions.
The fact that stress can overwhelm the rational and cognitive areas of the brain isn’t new — in the short term, stress hormones can impair function and with repeated exposure, can even kill brain cells there. “The PFC is a very stress-sensitive and malleable brain region,” says Bruce McEwen, professor of neuroscience at Rockefeller University, who edited the study for the Proceedings of the National Academy of Sciences.
What’s revealing about the current results, however, is that CBT, which researchers thought could counter this effect, doesn’t always do the job. That may be because scientists haven’t fully appreciated the combined effect that fear and stress may have on the brain. In the study, fear alone didn’t trigger the stress response. The participants showed no elevations in stress hormones during the first part of the experiment, even though they were afraid of being shocked before being trained in CBT.
Similarly, patients given CBT for depression may use it readily to cope with being snubbed by a friend — but be devastated by the same event if the boss has also been on their case all day.
Rather than suggesting that CBT may not be useful, however, Phelps thinks that her research suggests that it may take practice for it to succeed. Under stress, people’s brains go on auto-pilot, and pre-set reactions become the priority while abstract, logical and reasoned thinking —the type encouraged by this therapy— is reduced. It may take repeated trials to actively engage CBT skills and overcome the instinctual stress-driven response to crises. “Once something becomes more automatic, it relies less on the PFC,” Phelps says, “If you really practice and it becomes second nature, [stress] shouldn’t matter so much.”
Laws suggests that the results also mean medications such as beta blockers might be more important for certain patients who don’t respond initially to CBT, since these drugs can reduce stress responses. Other researchers are studying different medications that affect the PFC, since some work hints that how the PFC is activated in the stress response could distinguish between patients who respond to CBT and those who don’t.
CBT’s effectiveness might also be enhanced by actually introducing a little bit of stress when it is learned, to better simulate a real-world scenario. Research on resilience conducted among Navy Seals and found that their highly stressful training is critical to their ability to stay rational under duress. And mild stress itself has been shown to improve learning and increase resilience. They key, of course, will be in figuring out how much stress is just enough — something that varies from person to person, and even from session to session.