A surge in OCD symptoms has been detected in survivors of the Hamas-led massacre in Israel’s western Negev on Oct. 7, 2023, solidifying the link between trauma and obsessive-compulsive disorder, according to a study published by the Hebrew University in Jerusalem in late August.
Nearly one in four of the survivors reported new-onset OCD symptoms after the attacks, with many others seeing pre-existing symptoms worsening, according to the study.
“This is the first time we’ve been able to show directly that acute trauma can also trigger obsessive-compulsive symptoms,” either sparking OCD or intensifying existing symptoms, said professor Kalanthroff, who worked closely with students Shir Berebbi and Mor David on data collection and analysis, and with professor Helen Blair Simpson, a leading authority on OCD and trauma at Columbia University.
The research followed 132 adults, half of whom survived the Hamas-led onslaught in the Israeli communities of the Gaza Envelope.
Four to six months later, nearly 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.
According to the study, psychologists have long suspected a connection between trauma and OCD, given the high overlap with post-traumatic stress disorder (PTSD), but most of the evidence was indirect.
The new findings suggest that trauma severe enough to bring about PTSD may also trigger OCD—even if not previously present—with PTSD symptom severity partially explaining the rise in compulsive behaviors.
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 offer a fragile sense of control in an environment where control had been violently stripped away.
But various other symptoms were also evident, ranging from compulsive cleaning to ordering.
The researchers caution that their findings, while striking, are limited by reliance on self-reported symptoms rather than clinical interviews.
“Treatment for trauma-related disorders needs to be more holistic,” said Simpson. “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 study highlights the hidden psychological costs of conflict, which may reverberate across generations.