Thousands of Israelis were using mind-altering substances when Hamas fighters attacked a desert festival on Oct. 7.  Now, scientists are analyzing how these drugs affected the festival goers during extreme trauma.

According to The New York Times, some 4,000 revelers were gathered on Oct. 6 at a field in southern Israel near the Gaza Strip border. At dawn, Hamas-led terrorist killed 1,200 people, including 360 of those at the festival. Many of the festival attendees were under the influence of substances such as LSD, MDMA, and ketamine as they suffered the attack.

A group of Israeli researchers from the University of Haifa are studying the interaction of trauma and psychedelics, using the experiences of the Tribe of Nova festival goers as case studies. The scientists said that they are analyzing how psychedelics affected those in the face of such extreme trauma. The information might provide valuable insight that could help patients after a traumatic event.

While these mind-altering substances are illegal in most countries, including Israel, they have been scrutinized by experts for use in psychiatric settings. For example, careful doses of drugs such as MDMA and psilocybin, the active ingredient in “magic mushrooms,” might be useful in treating post-traumatic stress disorder (PTSD). While traditional psychopharmacology and psychotherapy are the mainstays of the treatment of PTSD currently, psychoactive drugs, also known as psychedelics, are being studied for their novel role in the treatment of PTSD patients.

Of the more than 650 Nova survivors surveyed, roughly 23% reported that they took hallucinogens like LSD, also known as acid, and 27% used MDMA, a synthetic drug that acts as a stimulant and hallucinogen, commonly known as Molly or Ecstasy. Many of the festival attendees used more than one substance, says the New York Times.

Preliminary results from the research study reveals that different participants had different experiences while on the mind-altering drugs when the attack began. Some felt invincible, while others reported extreme clarity and resolve. Still others were too paralyzed by the drugs to realize what was happening.

“We only hear the stories of those who made it out alive,” said Roy Salomon, a professor of cognitive science at the University of Haifa and a co-author of the study. “So, our understanding is influenced by survivors’ bias.”

Roee Admon, a University of Haifa psychology professor, and a co-author of the study says there are two main questions to be answered: “How is the traumatic event experienced under different psychedelics, and what might the long-term clinical impact be?”

So far, of those who survived the attack, some appear to be recovering well while others report feeling numb and detached. Others admit they’ve increased their drug use since the incident.

The University of Haifa researchers plan to follow the survivors for years, tracking their neural activity with functional magnetic resonance imaging (fMRI). It appears that those who took MDMA are recovering better and showing fewer severe symptoms of PTSD, according to the study’s early findings.

In fact, the MDMA users credit the drug for aiding their survival. Admon explains that perception of trauma may influence one’s ability to cope, so those under the influence of MDMA may have had a less traumatic impact.

On the other hand, those who took ketamine, a psychedelic with a tranquilizing and dissociative effect, appeared to be the hardest hit. Right after the Nova massacre, therapists and other experts established a volunteer network called Safe Heart that has assisted more than 2,200 survivors with psychological support.

“Most people who undergo a traumatic experience do not develop PTSD,” noted Admon. “Identifying those who do and treating them as early as possible is critical to their healing.”