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Intrusive Memories After Trauma May Be Shrunk By Anti-Inflammation Drug

People were given a dose of hydrocortisone shortly after watching movie scenes of “extreme violence”.


Tom Hale


Tom Hale

Senior Journalist

Tom is a writer in London with a Master's degree in Journalism whose editorial work covers anything from health and the environment to technology and archaeology.

Senior Journalist

An anatomical of a human head showing its brain

"The findings reported here build on previous studies that target the emotions that underlie involuntary memory", one of the researchers said. Image credit: AgriTech/

Taking a single pill of an anti-inflammatory drug immediately after a traumatic event could help people in the process of forgetting intrusive memories, according to a new trial at University College London (UCL). It’s still extremely early days for the research, but the team behind the project suggests that this treatment has some potential to help some people with post-traumatic stress disorder (PTSD).

The drug in question is hydrocortisone, an anti-inflammatory steroid used to treat conditions such as arthritis. This is a form of cortisol, the so-called "stress hormone" that's best known for producing the "fight or flight" response.


In the new study, 60 people were given 30 milligrams of hydrocortisone and 60 were given a placebo drug. The participants were then shown scenes of “extreme violence” from the R-rated French psychological thriller Irréversible

They found that the group who were given hydrocortisone a few minutes after being shown several very upsetting videos had less distressing intrusive memories than those who had been given a placebo drug.

Of course, watching a shocking movie cannot be compared to a traumatic life event and there’s no indication yet that the findings could be applied to people who experience real-life trauma

However, the researchers believe their study highlights how hydrocortisone might impact the consolidation of intrusive negative memories. It’s not certain how this mechanism works, but it is known that elevated levels of cortisol, the body's main stress hormone, can have a profound effect on emotional and cognitive processing.


"Persistent distressing, involuntary or 'intrusive' memories are a core feature of PTSD. Unlike other psychological disorders, the onset of PTSD caused by a single trauma can reliably be traced back to the occurrence of a specific, often life-threatening event that generates long-lasting intrusive memories", Vanessa Hennessy, lead author and PhD candidate at UCL's Division of Psychology & Language Sciences, said in a statement

"The findings reported here build on previous studies that target the emotions that underlie involuntary memory, with the aim of reducing how often they happen and how vivid they are – whilst still leaving the ability to recall the memory voluntarily", she added. 

Interestingly, the team also noticed that men and women responded differently to the drug depending on the levels of sex hormones in their bodies. Men with high levels of estrogen appeared to have the least upsetting memories for a week after watching the video. Conversely, women with high levels of estrogen appear to have the highest level of bad memories.

This led the researchers to conclude that studies should look further at how sex hormone levels impact the formation of memories in people with PTSD, and may influence the way they respond to treatments.


"Our work shows how important it is to do careful experiments with healthy people to work out whether and how a drug like hydrocortisone could work. After all, our results seem to show that there might be conditions that make the drug harmful in some people," Hennessy continued.

The study was published in the journal Translational Psychiatry


healthHealth and Medicinehealthmedicine
  • tag
  • medicine,

  • memory,

  • stress,

  • cortisol,

  • drug,

  • PTSD,

  • memory formation,

  • trauma,

  • hydrocortisone