Infidelity Associated With Ptsd-related Symptoms and Poorer Psychological Outcomes

Infidelity associated with PTSD-related symptoms and poorer psychological outcomes

Discovering that a partner has not been faithful can bring great distress to an individual. Many have described their experiences as traumatic as their thoughts frequently drift back to the moment when they found out about their partner’s infidelity and these thoughts can’t seem to go away. Perhaps surprising (or unsurprising) to some, infidelity also has a rather high occurrence rate, with up a quarter of committed relationships experiencing it at some point in time (Blow & Hartnett, 2005 as cited in Roos, O’Connor, Canevello & Bennett, 2019). In Singapore, infidelity is the leading cause of divorce and the number of infidelity cases in committed relationships has been on the rise (Department of Statistics Singapore, 2019). Given the traumatic nature of infidelity and the high prevalence of unfaithfulness in relationships, it is crucial that scientific studies examine how infidelity may affect one’s psychological well-being.

The Current Study


According to the Diagnostic and Statistical Manual of Psychiatric Disorders- (DSM-5), to be diagnosed with post-traumatic stress disorder (PTSD), a threat to one’s life or potential for injury would have to be present. However, an increasing number of research has shown that a life-threatening event is not required for PTSD symptoms to emerge. Given how discovering a partner’s infidelity is almost always characterised as traumatic for an individual, the researchers seek to determine if PTSD symptoms follow the discovery of infidelity in a partner.


Roos and colleagues (2019) recruited 73 young unmarried adults who were in a committed relationship in the last five years in which they were cheated on by their partners. Participants who were cheated on in the last month were excluded as the symptoms of PTSD has to be experienced more than one month after the traumatic event has occurred to meet the diagnostic criteria of DSM-5. Participants filled in a few questionnaires measuring their perceived stress, anxiety symptoms, depressive symptoms, infidelity-related PTSD symptoms and post-traumatic beliefs.


1. A significant number of participants reported infidelity-related PTSD symptoms.

45.2% (33 of 73 participants) of the participants met or surpassed the cut-off score for possible PTSD. Infidelity-related PTSD symptoms can be broken down into three main themes: 1) Intrusive thoughts (eg. “I thought about it when I didn’t mean to”), 2) Avoidance (eg/ “I tried not to think about it”), and 3) Hyperarousal (eg. Reminders of it caused me to have physical reactions, such as sweating, trouble breathing, nausea, or a pounding heart.”) (Roos et al., 2019, p.6). Almost half of the participants reported significant struggles with intrusive thoughts about their partner’s infidelity, high intentional avoidance of the issue altogether and problematic physiological responses after experiencing infidelity. To put things into perspective, the prevalence of PTSD after experiencing a non-interpersonal traumatic event (eg. earthquakes, accidents) is around 4% to 9%. For interpersonal traumatic events as defined by the DSM-5, the prevalence rates of PTSD go up to around 12% to 65%. This shows that there is a rather high chance of developing PTSD-like symptoms following infidelity.

2. Infidelity-related PTSD symptoms are associated with vulnerability to depression, anxiety and stress.

The researchers found that infidelity-related PTSD symptoms were associated with higher levels of depressive symptoms. These depressive symptoms include feeling worthless, general fatigue and a general loss of pleasure in everyday activities that used to bring them joy. They also found that the more infidelity-related PTSD symptoms a participant reported, the more perceived stress and anxiety symptoms they displayed. However, this finding was less robust as compared to the association between infidelity-related PTSD symptoms and depressive symptoms. Perceived stress relates to feelings of being unable to cope, anger and nervousness the participant showed in the past month. Anxiety symptoms include being unable to relax, difficulty breathing and frequent issues with heart-pounding or racing.

3. Infidelity-induced PTSD symptoms might bring about poorer mental health outcomes by changing one’s beliefs system.

The crumbling of one’s core beliefs makes infidelity a very traumatic event. Usually, our core beliefs are generally rather positive, we tend to think that our close ones will not hurt us and that we are strong resilient individuals. However, after being cheated on by a partner, our positive beliefs about the world and ourselves that we once took for certain and true are suddenly being challenged. In this study, participant’s post-traumatic beliefs were grouped into 3 themes: 1) Negative beliefs about the self (eg. “I am a weak person.”), 2) Negative beliefs about the world (eg. “Everyone is out to hurt me.”), and 3) Self-blame related to partner’s infidelity (eg. The event happened because of the way I acted”).

The study revealed that post-traumatic beliefs related to participants’ experience with infidelity could be a mechanism by which higher PTSD related symptoms lead to greater feelings of stress, anxiety and depression.

To illustrate this, take for instance a participant who cannot stop thinking about their partner’s infidelity. They might then feel that they can no longer trust anyone (Negative belief about the world). Thus, they are now constantly on alert and anxious, fearing that someone else they trust might betray them too.

Also, a participant who displays high infidelity-related PTSD symptoms might constantly think about the reason for their partner’s unfaithfulness and they might start to think of themselves as weak for not being able to stop thinking about the incident (Negative belief about self). As a result of this new belief, they might feel more depressed.

If one’s belief system is unchanged, then perhaps, one might not feel overly depressed or anxious post-infidelity.


After finding out that one’s partner has been unfaithful, it is not uncommon to hear one say that it felt as though their entire world has crumbled. Although experiencing infidelity is not a life-threatening event the same way an earthquake might be, this study has shown that individuals who have been cheated on exhibit symptoms very similar to those who have been through trauma. Especially for young adults who are new to relationships, experiencing such a betrayal might be even more distressing as it challenges their arguably still rather rosy view of the world. The PTSD symptoms experienced after infidelity might not only affect their current psychological well-being and world view, it can also be carried over to future relationships. The trauma can make one suspicious towards any other one who they may cross path with in the future and negatively impact subsequent forming of healthy romantic or platonic relationships. If you are struggling with a partner’s infidelity, you can click here to learn how you can better cope with it.


Roos, L. G., Oconnor, V., Canevello, A., & Bennett, J. M. (2019). Post‐traumatic stress and psychological health following infidelity in unmarried young adults. Stress and Health, 35(4), 468–479. doi: 10.1002/smi.2880

Department of Statistics Singapore. (2019, July). Statistics on Marriage and Divorces Reference Year 2018. Retrieved December 23, 2019, from

Article written with Charmaine Leong. Charmaine is a psychology undergraduate from the National University of Singapore (NUS). Charmaine is an aspiring clinical psychologist who is passionate about raising awareness of mental health issues in Singapore. She is currently on internship with ImPossible Psychological Services under the supervision of senior clinical psychologist, Haikal.

Categories: Relationship
Muhammad Haikal Bin Jamil

About the Author

Haikal received his Master degree at the National University of Singapore (NUS), under a full scholarship awarded by the National Council of Social Service (NCSS). Before entering private practice, he has gained much experience in both hospital and social services settings.

View Full Bio or Read More Posts