“Can thinking about death kill me?” – Thought-Action Fusion in suicidality

Imagine the following scenario: You’re waiting for your train at the station and there’s an announcement telling you to stand back for a train passing through. You see that train approaching at high speed and start wondering: “What if I walked three steps to the front and jumped?”

A very scary thought indeed and I’m sure some people reading this article will have had that thought, or a variety of it, at some point of time- I know I have. Now, still picturing this situation, ask yourself the following: Does having this thought (you might even call it a suicidal thought) put you in actual danger of committing suicide? Personally, I feel quite secure about myself not taking those three steps to the front and onto the railway tracks but this will be different for different individuals. In this blog, I will describe thoughts like these in more depth based on a new study we published on a construct called Thought-Action Fusion (or short: TAF) and its association with depression and suicidality.

What is Thought-Action Fusion?

Thought-Action Fusion has been brought up in scientific literature by Shafran, Thordarson, and Rachman more than 20 years ago. It is defined as “the belief that your thoughts are the same as the corresponding actions”. This definition includes two major components relating to morality and likelihood, that is, the belief that your thoughts are morally equivalent to corresponding actions and that your thoughts increase the likelihood of these actions, respectively. Translating this to the train example, morality TAF is the belief that having the thought of jumping is morally equivalent to committing suicide. Putting this differently: If you think about jumping, you’re a suicidal person. It’s easy to see how morality TAF might increase bad thoughts about yourself since it is impossible to shut down such weird thoughts from time to time even if the corresponding actions couldn’t be further from reality. While Shafran, Thordarson, and Rachman have first named and defined morality TAF in scientific literature, it has already been addressed informally in the bible, which is taking a very strong stance on the morality side of TAF:

You have heard that it was said, “Do not commit adultery.” But now I tell you: Anyone who looks at a woman and wants to possess her is guilty of committing adultery with her in his heart. (Matthew 5:27-28)

The bible isn’t one of my regular reads, so the reason I know about this quote is that it’s mentioned in the original TAF publication, which is rather odd for scientific literature. In any case, you see that even back during those good old days of early Christianity, a heavy burden was placed upon people with regards to morality TAF and it’s easy to picture the stress such statements pose for faithful believers of such claims.

I’ve discussed the morality side of TAF now but what about its likelihood side? Likelihood TAF is defined as “the belief that thinking about an unacceptable or disturbing event makes that event more probable, more likely to happen in reality”. Translating this to the train example from the beginning, it means you think that you’re more likely to jump in front of the train once you’ve had the thought of doing so. To a certain extent I would agree with that notion since actions are usually predated by corresponding conscious or unconscious thoughts. If I eat a banana, for example, I have consciously or unconsciously thought about eating a banana before. However (and placing a strong emphasis on however here), thoughts are certainly no obligation for subsequent action. So even if I think about jumping in front of that train, personally I feel quite alright with staying on the platform. This means I can leave the thought as what it is, namely a weird aberration of my brain.

Now that I explained the two parts of TAF, it will be helpful to give some description of the initial clinical and scientific application of TAF, which was done in obsessive-compulsive disorder, or short: OCD.

Thought-Action Fusion in OCD

You might have heard about OCD already but it’s important to give a short overview about what this disabling condition involves. OCD, as the name implies, consists of two parts named obsessions and compulsions. Obsessions describe persistent, unwanted beliefs or urges that lead to distress in patients experiencing them. These are usually suppressed or neutralised with actions. Compulsions, on the other hand, are repetitive behaviours- either physical or mental- that constitute a response to obsessive thoughts or occur rigidly. Oftentimes patients with OCD suffer from both obsessions and compulsions and these are thematically related. For example, a patient might have thoughts about a loved one dying (obsession) if a light switch isn’t switched on and off for 50 times (compulsion). This combination of obsessions and compulsions, however, is not necessary to qualify for a diagnosis and there are patients who suffer only from one or the other.

Relating this back to TAF, it has been proposed that TAF promotes unhelpful behaviours in patients with OCD or on the verge of developing the disease. For example, picture yourself having recurring thoughts about killing a loved one. If you identify this as a mere thought and unrelated to your actions, you can simply dismiss it as a weird thing happening once in a while. If you fuse thoughts and actions, however, and feel that due to your thought there now is an increased risk of yourself killing your loved one (likelihood TAF) or that you are morally responsible for this thought (morality TAF), you might be more likely to try and do something against having the thought. This could take the form of active attempts at thought suppression or engagement in compulsive behaviours. Although these behaviours might, in turn, eliminate these thoughts in the short term, research has shown that thought suppression actually increases the frequency of these thoughts occurring long-term, thus aggravating disease severity.

Psychological therapies such as cognitive behavioural therapy (or short: CBT) often try to teach patients that thoughts are unrelated to actions (so you’re not more likely to kill your loved one even if you’re plagued by the thought). To you, this might seem like an easy thing to do but TAF can be experienced as difficult to shift. On top of this, I would argue that many of us experience TAF to some extent. To see this, try to challenge your own TAF beliefs by thinking about- or writing down- sentences such as “I hope X dies today in a car crash” or “I will strangle X while they are sleeping” Exchange X here with the name of the most important person in your life. Many people find thinking about and writing down such sentences hard or feel at least slight unease when doing so, which shows how we all have a certain extent of superstition when it comes to the impact of our thoughts. This is why writing down such sentences is an actual example of how patients are trained to unlearn TAF and so-called magical thinking (which has been argued to potentially be the broader category that TAF is falling into) in psychotherapy. Recently, I came across the following tweet by psychiatrist David Veale, which beautifully shows the progress of one of his patients in unlearning his/ her magical thinking and TAF beliefs:

Thought-Action Fusion in Suicidality

Following this excursion into the history of TAF and its relationship to OCD, let’s go back to how TAF might relate to suicidality. People suffering from depression and suicidality have a relationship to death and suicide that is very similar to how OCD patients suffer from obsessions. Just as OCD patients ruminate intensely about obsessions, depressed patients do so very vividly about death and suicide. Here, mood changes often aggravate their feelings of hopelessness and this, combined with suicidal TAF, might potentially put patients in danger of actually harming themselves. To date, however, the hypothesis of TAF being also expressed by depressed and suicidal patients has merely been speculation, so Bergljot Gjelsvik (who is lead author of the study) wanted to test whether her clinical observations were indeed supported in research. As a first step of pursuing this question, we set out to investigate whether TAF was indeed part of patients’ experiences. To this end, we developed a questionnaire to ask patients about whether they experienced TAF. We included questions that determined how much patients agreed with statements such as “if I think of myself being in a plane crash, this increases the chance that I will be in a plane crash” or “if I think about me killing myself, this increases the chance that I will kill myself”. Next, we analysed how questions related to each other and whether specific sets of questions potentially assessed common underlying constructs. In line with the way the questions were structured, we expected four sets of questions to stick together statistically; that is, (i) those having negative versus positive content, (ii) those having self-related versus other-related content, (iii) those including the theme of death and suicide or not, and (iv) those that included controllable (e.g., eating healthily) versus uncontrollable (e.g., plane crash) themes. Contrary to these four expected groupings, however, three sets of questions stood out that were combinations of our hypothesised groupings:

  1. Those that related TAF to things not in people’s own control (e.g., thoughts about being in a plane crash), which we termed uncontrollable TAF.
  2. Those with self-related suicidal content including thoughts about killing oneself, which we termed self-suicidal TAF.
  3. The last set was constituted by questions about positive, controllable TAF such as “if I think of myself having fun on a holiday, this increases the chance that I will have fun on a holiday”.

Having developed this questionnaire, we tested how these questions were answered by three different groups of currently healthy individuals:

  1. Those who never suffered from depression or suicidality
  2. Those who suffered from depression but not from suicidality
  3. Those who suffered from both depression and suicidality

After handing the questionnaire to these three groups, we observed a very interesting pattern of differences across the three sets of TAF questions, which I have simplified in the table below:

TAF No Depression History of Depression but not Suicidality History of Depression and Suicidality
Uncontrollable Low High Low
Self-Suicidal Low High High
Positive Controllable High Low Medium


Trying to interpret these findings, it seems that individuals without a history of depression have a comparably low tendency to fuse thoughts and actions when it comes to uncontrollable or suicide-related content, yet a high tendency when it comes to positive content that is in their control. This might emphasise a realistic and somehow optimistic outlook on the influence of one’s thoughts that could be protective against the development of depression. Contrary to this, for individuals with a history of depression fusion of positive-controllable thoughts and actions was somewhat lower in both of these groups, which could reflect a tendency to see positive events as out of one’s control. This way of thinking might constitute a risk of falling back into depressive illness.

The third, and most striking finding to take from these results was that individuals with a history of suicidality showed a very specific tendency to fuse self-related suicidal thoughts and actions but no other content. This could reflect a highly dangerous thought pattern, in which only thoughts about death and suicide are “capable” of resulting in an action or an event. If you imagine yourself thinking this way in a period of crisis, it is easy to see how this might make you feel trapped and hopeless in a negative situation with the only imagined escape from this situation being to kill yourself. Further support for this last interpretation came from the final part of our study, in which we asked our questions again to all individuals with a history of depression but after having them recollect a period of crisis before answering. Following such recollections of difficult times, those individuals with a history of suicidality increased much more in their TAF towards both uncontrollable and self-suicidal content and decreased much more in their TAF towards positive and controllable content than those individuals without a history of suicidality. This further highlights the possible danger of relying upon a thought pattern, in which only thoughts about uncontrollable and self-suicidal ideas seem capable of future action as this entraps people in situations without a way out.

In the future, researchers need to verify whether the findings from our study hold up to further scrutiny and whether they do indeed have implications for mental health care in clinical practice. It would be particularly interesting to test whether there are techniques that can help patients overcome dysfunctional TAF patterns. In OCD, two studies have been conducted to test treatments for TAF: One tested whether bias modification training (i.e., presenting individuals with the right response to a thought) could lower TAF and the other whether psychoeducation (i.e., simply explaining why thoughts do not relate to actions) helped. While both treatments were effective at lowering Morality TAF, however, unfortunately they did not help people lower their likelihood TAF. Thus, the effectiveness of these treatments for TAF in depression might be doubtful. Another possible technique could be mindfulness meditation, which trains people to see thoughts as something separate from actions. Specifically, mindfulness focuses on learning to observe, being aware, and accepting thoughts. As such, you should only pursue thoughts if you want to pursue them but with no obligations to do so. A very preliminary case series in three patients showed some promising results of mindfulness as a treatment for TAF. Yet, much larger studies are involved to draw actual inferences for its potential clinical benefits in TAF. Ultimately, such research of specific treatment techniques can then hopefully increase our understanding on whether people commit suicide partly due to increased TAF. In turn, we could take preventive action and hopefully save the unnecessary lives lost to the debilitating mental illness that is depression.



  1. Berle, D., & Starcevic, V. (2005). Thought–action fusion: Review of the literature and future directions. Clinical Psychology Review, 25, 263– https://doi.org/10.1016/j.cpr.2004.12.001
  2. Gjelsvik, B., Kappelmann, N., von Soest, T., Hinze, V., Baer, R., Hawton, K., & Crane, C. (2018). Thought–Action Fusion in Individuals with a History of Recurrent Depression and Suicidal Depression: Findings from a Community Sample. Cognitive Therapy and Research, 1–12. https://doi.org/10.1007/s10608-018-9924-7
  3. Marino-Carper, T., Negy, C., Burns, G., & Lunt, R. A. (2010). The effects of psychoeducation on thought-action fusion, thought suppression, and responsibility. Journal of Behavior Therapy and Experimental Psychiatry, 41(3), 289–296. https://doi.org/10.1016/j.jbtep.2010.02.007
  4. Shafran, R., Thordarson, D. S., & Rachman, S. (1996). Thought-action fusion in obsessive compulsive disorder. Journal of Anxiety Disorders, 10(5), 379–391. https://doi.org/10.1016/0887-6185(96)00018-7
  5. Siwiec, S. G., Davine, T. P., Kresser, R. C., Rohde, M. M., & Lee, H.-J. (2017). Modifying thought-action fusion via a single-session computerized interpretation training. Journal of Obsessive-Compulsive and Related Disorders, 12, 15–22. https://doi.org/10.1016/j.jocrd.2016.11.005
  6. Wilkinson-Tough, M., Bocci, L., Thorne, K., & Herlihy, J. (2010). Is mindfulness-based therapy an effective intervention for obsessive-intrusive thoughts: A case series. Clinical Psychology and Psychotherapy, 17(3), 250–268. https://doi.org/10.1002/cpp.665
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Nils Kappelmann

I'm a PhD student at the Max-Planck-Institute of Psychiatry in Munich, Germany, investigating potential biomarkers in the psychotherapeutic treatment of depression.