woman undergoing psychology test
When the lamp in the figure is red, the subject hears an unpleasant sound in the earphones and learns to associate the visual signal with discomfort.

© Anna Nilsen

Psychological treatment

New PTSD meds take advantage of body's own cannabinoids

A medication that boosts the body’s own cannabis-like substances, endocannabinoids, shows promise to help the brain un-learn fear memories when these are no longer meaningful. This according to an early-stage, experimental study on healthy volunteers at Linköping University.

The new findings give hope that a new treatment can be developed for post-traumatic stress disorder, PTSD.

portrait of leah mayo
Leah Mayo

© Anna Nilsen

“We have used a medication that blocks the way the body breaks down its own cannabis-like substances, or ‘endocannabinoids’. Our study shows that this class of medications, called FAAH inhibitors, may offer a new way to treat PTSD and perhaps also other stress-related psychiatric conditions. The next important step will be to see if this type of medication works in patients, particularly those with PTSD”, says Leah Mayo, senior post-doctoral fellow and lead investigator on the study, which was carried out in the laboratory of Professor Markus Heilig at the Center for Social and Affective Neuroscience, CSAN, Linköping University, and published in the scientific journal Biological Psychiatry.

Recommended article

Photo

Traumatized patients

Improving treatment of anxiety disorders

Traumatic experiences can become deeply entrenched in a person's memory. How can fears following a traumatic event be reduced in the long term and prevented from becoming a permanent stress-related disorder? Researchers at the Mainz University Medical Center have recently shed new light on these questions. The key to their approach lies in firmly anchoring new, positive experiences in the…

Post-traumatic stress disorder, PTSD, arises in some – but not all – people who have experienced life-threatening events. A person affected by PTSD avoids reminders of the trauma, even when the danger is long gone. Over time, these patients become tense, withdrawn, and experience sleep difficulties. This condition is particularly common among women, where it is often the result of physical or sexual abuse. It is highly debilitating, and current treatment options are limited.

PTSD is currently best treated using prolonged exposure therapy, PE. In this treatment, patients are repeatedly exposed to their traumatic memory with the help of a therapist. This ultimately allows patients to acquire new learning: that these memories no longer signal imminent danger. Although clinically useful, effects of PE are limited. Many patients do not benefit, and among those who do, fears frequently return over time. The scientists who carried out the current study examined whether fear extinction learning, the principle behind PE therapy, can be boosted by a medication.

Photo
By measuring the activity of small facial muscles, the researchers can detect whether the subject reacts with discomfort, joy, surprise or another emotion.

© Anna Nilsen

The researchers tested a pharmaceutical that affects the endocannabinoid system, which uses the body’s own cannabis-like substances to regulate fear and stress-related behaviors. The experimental medication results in increased levels of anandamide, a key endocannabinoid, in regions of the brain that control fear and anxiety. The medication accomplishes this by blocking an enzyme, FAAH (fatty acid amide hydrolase), that normally breaks down anandamide. The FAAH inhibitor tested by the researchers was originally developed for use as a pain killer, but was not effective enough when tested clinically. 

This early-stage experimental study was randomised, placebo-controlled and double-blind, which means that neither the participants nor the scientists knew who was receiving the active drug (16 people) and who was receiving placebo (29 people). Participants were healthy volunteers. After taking the drug for 10 days, they underwent several psychological and physiological tests. In one of these, participants learned to associate a highly unpleasant sound, that of fingernails scraping across a blackboard, with a specific visual cue – an image of a red or blue lamp. Once they had learned to respond with fear to the previously innocuous image of the lamp, they were repeatedly re-exposed to it, but now in the absence of the unpleasant sound. This allowed them to unlearn the fear memory. The following day, the scientists measured how well participants remembered this new learning: that the lamp was no longer a threat signal. This process of un-learning fear is the same principle on which PE therapy for PTSD is based.

“We saw that participants who had received the FAAH inhibitor remembered the fear extinction memory much better. This is very exciting”, say Leah Mayo. “Numerous promising treatments coming out of basic research on psychiatric disorders have failed when tested in humans. This has created quite a disappointment in the field. This is the first mechanism in a long time where promising results from animal experiments seem to hold up when put to test in people. The next step, of course, is to see whether the treatment works in people with PTSD”, adds professor Markus Heilig.


Source: Linköping University

04.09.2019

Read all latest stories

Related articles

Photo

LSD & Psilocybin

Microdosing drugs – exploring risks and benefits

The practice of taking small, regular doses of psychedelic drugs to enhance mood, creativity, or productivity lacks robust scientific evidence, say scientists. The process, called microdosing, has…

Photo

Oral contraceptives

Can birth control pills keep you from recognising emotions?

The pill could be blurring your social judgement ‒ but perhaps not enough so you'd notice. By challenging women to identify complex emotional expressions like pride or contempt, rather than basic…

Photo

New biological approach

Old antibiotic could become valuable depression treatment

An antibiotic used mostly to treat acne has been found to improve the quality of life for people with major depression, in a clinical trial from Deakin University.

Related products

Eppendorf – Mastercycler nexus X2

Research Use Only (RUO)

Eppendorf – Mastercycler nexus X2

Eppendorf AG
Sarstedt – Low DNA Binding Micro Tubes

Research Use Only (RUO)

Sarstedt – Low DNA Binding Micro Tubes

SARSTEDT AG & CO. KG
Shimadzu – CLAM-2030

Research Use Only (RUO)

Shimadzu – CLAM-2030

Shimadzu Europa GmbH