Trauma, PTSD, and OCD - Trauma can cause or increase Obsessive-compulsive disorder (OCD) symptoms

By: Tom Cloyd - 6 minute read

(Published: 2025-09-19; reviewed: 2025-10-03:2321 Pacific Time (USA))

Page contents…

• OCD, anxiety, and PTSD ^
• What we have discovered about trauma, PTSD, and OCD to this point ^
• What this new study from Israel tells us ^
• Methodological limitations ^
• Implications for clinical work ^
• References ^
• Notes ^

OCD, anxiety, and PTSD ^{^}

Obsessive-compulsive disorder (OCD) is diagnosed most generally when one experiences obsessions - “recurrent and persistent thoughts, urges, or images that are experienced as intrusive and unwanted” or compulsions - “repetitive behaviors or mental acts that an individual feels driven to perform in response to an obsession or according to rules that must be applied rigidly”.²

It has been noted that “there are close relationships between the anxiety disorders and some of the obsessive-compulsive and related disorders (e.g., OCD)”.² Reviewing this website’s glossary descriptions of “anxiety”, one can easily see its relationship to posttraumatic stress disorder (PTSD), especially with the avoidance and arousal symptom clusters.³

What we have discovered about trauma, PTSD, and OCD to this point ^{^}

Previous studies have shown clear correlations between PTSD and OCD. In individuals with OCD, various studies have shown a coexisting PTSD rate of 19%⁴ to 31%⁵. Of individuals with PTSD, the OCD rate has been found to be “3.6 times that of the general population in some studies.”¹ But, such studies do not clarify what the causes of this association may be. Causal analysis has to involve two critical factors: observation of key variables across time, and control of extraneous (“confounding”) variables which, if not removed from an analysis, can only give rise to additional, irrelevant questions as well as confuse interpretation of the effects of variable(s) of interest.

What this new study from Israel tells us ^{^}

The circumstances of the tragic October 7 attack presented an opportunity to look closely at the possible relationship between traumatic stress and OCD. Sixty-six attack survivors were matched with 66 other individuals who served as controls - people who were fairly similar to the victims, and like them would have been affected by any other current events, but not the October 7 attack itself. Additionally, it is assumed that the matched control individuals had vicarious trauma exposure to the attack.¹ These “control subjects” allow a contrast with the victim subjects, since it may be assumed that both groups have been exposed to more or less the same irrelevant (confounding) variables. What that leaves us to examine is how the victim group differs from the control group.

Baseline OCD and PTSD symptoms existing before October 7 were obtained from victim and control groups through questionnaires involving recalled self-report. When symptoms were assessed at a second point in time - four to six months after the attack - and compared with baseline symptoms, “…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….”⁶

What was the origin of these symptoms?

• For victims, 16 of the 26 (62%) individuals with OCD post-attack did not have it before.
• For control individuals, 1 of the 5 (20%) with OCD post-attack did not have it before.
• Emergence of PTSD symptoms in the victim group was also very much higher than in the control group⁷

It seems clear that direct exposure to the attack led to future development of OCD diagnoses at a rate substantially higher than would be expected in the general population not exposed to the attack.

Of interest for future studies is the question of the persistence of symptoms over longer periods of time than those studied in this research, as well as consideration of which individuals exposed to traumatic experience are most likely to develop symptoms.⁷

Methodological limitations ^{^}

This new Israeli study has several limitations:

• The sample studied was a “convenience-sample”, not a random sample of the general population of interest (which is, of course, all of humanity). Inferences from the sample to the general population are therefore necessarily problematic, since the probability of accurate representation by the sample group cannot be calculated. Calculation of the statistical significant of sample findings is also impossible with such a sample.
• While using a control group of individuals matched to be significantly similar to the group exposed to the crucial independent variable is a standard research technique, it is an imperfect one, and does not necessarily allow statistical removal of irrelevant variables as completely as having a randomly chosen study group.
• Sample size was small. This increases the risk of sample findings’ being seriously deviant from actual (unknown) population parameters, which is what we actually want to know about.⁷

Implications for clinical work ^{^}

These results clearly indicate “the need for screening for OCD in trauma-exposed populations.”¹⁷ Also, when treatment for PTSD reduces or eliminates symptoms, tracking of OCD symptom dynamics seems warranted, as the relationship is yet to be determined, and it well may be that some or all of the OCD symptoms in an individual have the same ongoing cause as their PTSD symptoms.⁸

References ^{^}

American Psychiatric Association (Ed.). (2022). Diagnostic and statistical manual of mental disorders: DSM-5-TR (Fifth edition, text revision). American Psychiatric Association Publishing; /Library.

Brown, T. A., Campbell, L. A., Lehman, C. L., Grisham, J. R., & Mancill, R. B. (2001). Current and lifetime comorbidity of the DSM-IV anxiety and mood disorders in a large clinical sample. Journal of Abnormal Psychology, 110(4), 585–599. https://doi.org/10.1037/0021-843X.110.4.585

J. N. S. staff. (2025, September 19). Oct. 7 trauma likely caused spike in OCD symptoms, research shows. JNS.Org. https://www.jns.org/oct-7-trauma-likely-caused-spike-in-ocd-symptoms-research-shows/

Kalanthroff, E., Berebbi, S., David, M., & Simpson, H. B. (2025). Acute Trauma and OCD: Evidence from October 7th, 2023. Psychotherapy and psychosomatics, 1–22. Advance online publication. https://doi.org/10.1159/000548026 DOWNLOADABLE PDF: https://karger.com/pps/article-pdf/doi/10.1159/000548026/4424112/000548026.pdf

Petrova, K. (2025, September 19). Trauma can trigger obsessive-compulsive disorder, not just PTSD, new study shows. PsyPost - Psychology News. https://www.psypost.org/trauma-can-trigger-obsessive-compulsive-disorder-not-just-ptsd-new-study-shows/

Ruscio, A. M., Stein, D. J., Chiu, W. T., & Kessler, R. C. (2010). The epidemiology of obsessive-compulsive disorder in the National Comorbidity Survey Replication. Molecular Psychiatry, 15(1), 53–63. https://doi.org/10.1038/mp.2008.94

Notes ^{^}

 

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