It’s well known that the horrific events on October 7 and the war in Gaza since then have caused a major escalation in post-traumatic stress symptoms (PTSD), lack of sleep, more dangerous driving, and addictive behaviors among many Israelis.
Current assessments indicate probable PTSD in about one-third of the Israeli population and even higher numbers among those directly affected by these events in Israel and in Gaza. Beyond the destruction of homes and families, war alters mental processes in ways that are only beginning to be understood.
But when survivors of the Hamas terrorist attacks returned to what was left of their homes at Israel’s southern border, many carried with them more than anguish and PTSD.
A new Hebrew University of Jerusalem (HUJI) study shows that the trauma also triggered an unexpected surge in obsessive-compulsive disorder (OCD). It is the first direct evidence that acute trauma can trigger the onset of this harmful emotional disorder.
The obsessions and compulsions interfere with daily activities and cause a lot of distress. The symptoms include cleaning and hand washing; checking that doors are locked or that the gas is off; hoarding; asking for reassurance; repeatedly counting things; repeating words in their minds; ordering and arranging objects; and thinking “neutralizing” thoughts to counter the obsessive thoughts.
A team of Israeli psychologists and psychiatrists, joined by a professional from New York, noticed an unsettling pattern among survivors – obsessions and compulsions that hadn’t been there before or that had become exaggerated.
The research was led by HUJI’s clinical neuropsychologist Prof. Eyal Kalanthroff and by Prof. Helen Blair Simpson, who is director of the Center for the Obsessive-Compulsive and Related Disorders at the New York State Psychiatric Institute and a psychiatrist at the Irving Medical College of Columbia University, together with HUJI students Shir Berebbi and Mor David.
It has just been published in the journal Psychotherapy and Psychosomatics under the title “Acute Trauma and OCD: Evidence from October 7th, 2023.”
40% of those directly exposed met criteria for probable OCD
The team followed 132 adults – half of whom were survivors from towns and villages adjacent to Gaza that endured the brunt of Hamas’s assault. Four to six months later, almost 40% of those directly exposed to the violence met the criteria for probable OCD, compared to just seven percent of a matched control group elsewhere in Israel.
Among the survivors, nearly one in four reported new-onset OCD symptoms after the attacks, and many others saw that the symptoms they had before had gotten worse.
Psychologists have long suspected a connection between trauma and OCD, given the high overlap with PTSD. The team said the only study that has directly compared rates of OCD in those with and without trauma is a study of Vietnam veterans, which found that 406 veterans with extensive combat exposure exhibited significantly higher prevalence of OCD (5.5%) compared to 783 veterans without combat exposure (0.5%).
But no study to date has shown a causal effect of trauma on OCD onset; until now, most of the evidence was indirect. The team’s findings suggest that trauma severe enough to induce PTSD may also set the stage for OCD, with PTSD-symptom severity partially explaining the rise in compulsive behaviors.
THE FINDINGS support the “diathesis-stress” model of mental illness, in which genetic vulnerabilities interact with overwhelming stress to produce psychiatric disorders. In some cases, exposure to extreme, life-threatening violence was sufficient to trigger symptoms that had not previously been present.
Kalanthroff, who has collaborated on research with Simpson for a decade and was on sabbatical at her lab last year, told The Jerusalem Post that the most common new symptom was compulsive checking, often tied to fears of invasion or safety.
Survivors described repeatedly verifying locks, windows, and doors – behaviors that offered a fragile sense of control in an environment where control had been violently stripped away. However, various other symptoms were also evident, ranging from compulsive cleaning to ordering.
He added that the hidden psychological costs of conflict “may also be passed down to the next generation – not genetically, but from high stress caused to the children; it can reflect very badly on the family.”
The team cautioned that their findings, while striking, are limited by reliance on self-reported symptoms rather than clinical interviews. Still, the data suggest an urgent need for health systems to screen trauma survivors not just for PTSD and depression, but also for OCD, they said.
“Treatment for trauma-related disorders needs to be more holistic,” Simpson urged. “Clinicians should consider OCD symptoms alongside post-traumatic stress, because missing them means leaving people untreated for a condition that can deeply affect their lives.”
The gold standard for treating OCD is cognitive behavioral therapy (CBT), especially exposure and response prevention, in which the sufferers are gradually exposed to the thoughts or situations that trigger their obsessions. They learn to prevent themselves from engaging in the corresponding compulsions and are helped to manage their anxiety without performing rituals.
The technique is effective in 65% to 70% of cases, Kalanthroff said. “Sometimes, patients need a booster (maintenance) treatment. If a patient has both PTSD and OCD, the professional who treats him should be informed of this combination, because CBT has to be done somewhat differently. If not, the condition can get worse,” the HUJI neuropsychologist said.
Joining support groups and connecting with others who have OCD can provide mutual support and coping strategies.
He concluded that CBT is often combined with giving selective serotonin reuptake inhibitor medications for more severe cases. Deep brain stimulation – a surgical procedure that involves implanting a device to stimulate brain areas – is reserved for severe, treatment-resistant OCD, as is non-invasive treatment using magnetic fields to modulate brain activity.