How cortisol affects exposure therapy for anxiety disorders

Summary: Cortisol administration after exposure has no beneficial effects for patients suffering from phobias or anxiety disorders. Arachnophobic who received cortisol following exposure were more likely to relapse when they encountered spiders in a different context.

Source: RUB

Bochum-based psychologists have studied how the application of the stress hormone cortisol affects exposure therapy for anxiety disorders. The researchers knew from earlier studies that extinction learning, which constitutes the foundation of exposure therapy, can be reinforced by administering cortisol. However, the team headed by Professor Armin Zlomuzica at Zentrum für Psychotherapie (psychotherapy centre) at Ruhr-Universität Bochum (RUB) has demonstrated with a group of arachnophobics that an application of cortisol after exposure is not beneficial for the patients. Rubin, the RUB’s science magazine, reports about the results which were also published in the scientific journal Psychoneuroendocrinology.

“Various studies have shown that extinction can be accelerated or reinforced in healthy individuals by administering the stress hormone cortisol,” says Armin Zlomuzica. In these studies, patients always took cortisol prior to the therapy. The team from Bochum has now tested what happens if the drug is administered after exposure to the triggering object. The idea was that they would be able to use the pharmaceutical agent after successful exposure, thus reinforcing only the positive therapy outcomes.

Experiment with arachnophobics

50 individuals with arachnophobia took part in the study. Half of them were administered a cortisol tablet following exposure therapy, the other half were given a placebo. Before and after exposure, the researchers recorded the severity of each participant’s fear of spiders. To this end, the patients assessed their own fear subjectively; in addition, a behavioural approach test was performed, in order to gain an objective measure of each patient’s phobia. In the process, a therapist presents a spider in a terrarium and asks the patient to get as close to it as possible.

This shows a spider crawling on a person's hand
Arachnophobia is a widespread fear. The image is credited to Roberto Schirdewahn.

Immediately after therapy, most of the patients were able to approach the spider more closely than before. The researchers from Bochum are primarily interested in the long-term effects. This is why they repeated the behavioural approach test – one month and six months after exposure therapy and in two different contexts: in the room where the therapy had taken place, and in a different room with a different terrarium and a different supervisor.

Context is the key

“Our study has shown that the learned behaviour was much more strongly linked to the context following the application of the drug, which is not what we want in the long term,” explains Armin Zlomuzica. Patients who were administered cortisol were more likely to relapse when they encountered a spider in a different context. Accordingly, administering cortisol after exposure therapy doesn’t appear to have any benefits for the patients.

About this neuroscience research article

Media Contacts:
Armin Zlomuzica – RUB
Image Source:
The image is credited to Roberto Schirdewahn.

Original Research: Open access
“Post-exposure cortisol administration does not augment the success of exposure therapy: A randomized placebo-controlled study”. Friederike Raeder, Christian J. Merz, Martin Tegenthoff, Oliver T. Wolf, Jürgen Margraf, Armin Zlomuzica. Psychoneuroendocrinology Volume 99, January 2019, Pages 174-182. doi:10.1016/j.psyneuen.2018.09.015


Post-exposure cortisol administration does not augment the success of exposure therapy: A randomized placebo-controlled study

Cortisol administration prior to treatment can promote the efficacy of exposure-based treatments in specific phobia: cortisol has been proposed to reduce fear retrieval at the beginning of exposure and to enhance the acquisition and consolidation of corrective information learned during exposure. Whether cortisol exerts a beneficial therapeutic effect when given after exposure, e.g., by targeting the consolidation of new corrective information, has not been addressed so far to date. Here, we examined whether post-exposure cortisol administration promotes fear reduction and reduces return of fear following contextual change in specific phobia. Furthermore, the effect of cortisol on return of fear following contextual change (i.e., contextual renewal) was assessed. Patients with spider phobia (N = 43) were treated with a single session of in-vivo exposure, followed by cortisol administration (20 mg hydrocortisone) in a double-blind, placebo-controlled study design. Return of fear was assessed with behavioral approach tests (BATs) in the familiar therapy context (versus a novel unfamiliar context) at one-month and seven-month follow-up assessment. Exposure was effective in reducing fear from pre-treatment to post-treatment (i.e., 24 h after exposure) on fear-related behavioral (approach behavior during the BAT), psychophysiological (heart rate during the BAT) and subjective (fear during the BAT, spider-fear related questionnaires) measures of therapeutic outcome, with no add-on benefit of cortisol administration. Cortisol had no effect on contextual renewal at one-month follow-up. However, in a subsample (N = 21) that returned to the seven-month follow-up, an adverse effect of cortisol on fear renewal was found, with cortisol-treated patients showing an increase in subjective fear at the final approach distance of the BAT from post-treatment to seven-month follow-up. These and previous findings underline the importance of considering the exact timing of cortisol application when used as an add-on treatment for extinction-based psychotherapy: post-exposure cortisol administration does not seem to be effective, but might promote fear renewal at the subjective level.

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