Bloodcurdling movies and measures of coagulation: Fear Factor crossover trial
BMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h6367 (Published 16 December 2015) Cite this as: BMJ 2015;351:h6367
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Greatly fascinated and inspired by the work of Nemeth et al.1 suggesting an association between watching scary movies and upregulation of “fear factors” of coagulation activity we wondered whether such relation is merely an academic curiosity or might have meaningful implications for global health. As truly modern scientists we rephrased our question into a Google compatible search taking benefit of Google’s N-gram viewer (https://books.google.com/ngrams), a program which enables quantifying historical patterns of the occurrence of a word or phrase in both scientific and lay literature.2 Searching all English literature from the 1950s onwards from which time humankind has been exposed to horror movies on a large and systematic scale, we specifically assessed whether the occurrence of ‘scary movie’ and its associated synonyms ‘horror movie’ and ‘frightening movie’ were related to the frequency with which the terms ‘vein thrombosis’ or ‘venous thrombosis’ were used. Interestingly, the frequency patterns with which scary movies and venous thrombosis are reported in the literature show a remarkably close temporal association (Figure 1). Thus, our results extend those of Nemeth et al.1 to the real-life arena and suggest yet another blatantly hidden threat of modern life-style to humanity’s health.
References
1) Nemeth B, Scheres LJ, Lijfering WM, Rosendaal FR. Bloodcurdling movies and measures of coagulation: Fear Factor crossover trial. BMJ 2015;351:h6367
2) Michel JB, Shen YK, Aiden AP, Veres A, Gray MK, Pickett JP et al. Quantitative analysis of culture using millions of digitized books. Science 2011; 331(6014):176-182.
Figure 1 legend:
Google N-gram’s results for the search query “(scary movie*5 + horror movie*5 + frightening movie*5),(vein thrombosis + venous thrombosis)” showing the frequency of ‘scary movie’ and its associated synonyms ‘horror movie’ and ‘frightening movie’ (blue line) and the frequency of the terms ‘vein thrombosis’ or ‘venous thrombosis’ (red line) in the English literature from 1950 onwards. In order to clarify the temporal association between the two lines the frequency of scary movie and its synonyms was multiplied by five.
Competing interests: No competing interests
The authors present an interesting study examining the effect of watching horror movies on pro-coagulant factor activation ("blood curdling"). However, whilest they measured degree of fear on a visual analog scale (to demonstrate that the horror movie was scarier than the educational film), they failed to examine the correlation between degree of fear and degree of pro-coagulant activation. Clearly, if a subject was immune to a horror movie (e.g. they were a horror movie fan), their pro-coagulant activity would remain unchanged. Conversely, a very fearful person would be expected to have a much higher pro-coagulant response, according to the authors' hypothesis.
Secondly, the authors fail to consider the prior probability of their hypothesis being feasible. John Ioannidis and others have eloquently shown that the probability that a statistically significant observed result is in fact a TRUE POSITIVE is directly related to the probability of such a result being possible, or probable. Therefore, I would postulate that the observation of a change in Factor VIII activity is due to chance, and not as a consequence of watching horror films.
This hypothesis of a false positive finding is supported by the observation that characters in horror films, who surely have a very high fear level at the time of their assault or demise, tend to bleed profusely, with copious blood spattering over the entire scene. This suggests that their pro-coagulant activity, whether up-regulated or not, does little to prevent the exsanguination to which they are subject.
Competing interests: No competing interests
The research article findings that fear may cause increased factor VIII levels without thrombus formation has some important applications [1]. The results of the study could be translated to people with chronic fear or to people with chronic social phobia. Chronic fear in these groups in the light of the present study could possibly cause increased factor VIII levels in their blood which chronically may lead to thrombus formation resulting in the occurrence of stroke, venous thrombosis and cardiovascular diseases [2,3,4].
The results of this study stimulate further research directed on the question whether bloodcurdling phenomenon occurs in people with chronic fear also and whether it is associated with increased thrombus formation.
References
1. Nemeth B, Scheres LJ, Lijfering WM. Bloodcurdling movies and measures of coagulation: Fear Factor crossover trial. BMJ 2015;351:h6367.
2. Kamphuisen PW, Eikenboom JC, Bertina RM. Elevated Factor VIII Levels and the Risk of Thrombosis. Arterioscler Thromb Vasc Biol. 2001;21(5):731-8.
3. Jenkins PV, Rawley O, Smith OP, O'Donnell JS. Elevated factor VIII levels and risk of venous thrombosis. Br J Haematol. 2012;157(6):653-63.
4. Lasek-Bal A, Puz P, Kazibutowska Z. Elevated factor VIII level and stroke in patients without traditional risk factors associated with cardiovascular diseases.Neuropsychiatr Dis Treat. 2013;9:847-52.
Competing interests: No competing interests
Re: Bloodcurdling movies and measures of coagulation: Fear Factor crossover trial
Dear editor,
having our fingers in the pie of vascular disease, we read with a greedy interest the excellent paper from Nemeth et al1. With time, we acquired a taste for BMJ's New Year articles. This year's one is cherry on the cake. The researchers were able to cut the mustard and show convincing evidence that horror movies are bloodcurdling movies. We shall not polish the apple, and we sincerely congratulate the authors for it. We went bananas when we read their paper… but then we saw the video and we got ourselves into a stew over the feeling of a confounding factor in the authors' results.
The documentary is undoubtedly food for thought and seeing a big cheese comments on wine production in France is likely to drive you as cool as a cucumber (Not a high calorie diet). The horror movie shows rotten apples turning the screen red with blood and is not the cause of our trouble. Our attention was caught on the video by the two females on first raw going on a binge and bolting marshmallows down, a usual stress reaction2. We would like to sugar-coat our belief but think that authors might be in a pickle because of this. Indeed, pro-coagulant activity and specifically Factor VIII is increased during hyperglycemia3.
We do not want to make a hamburger out of their work, but we would milk the authors for the results of glycaemia, or urge them to confirm their fascinating observation under strict food restriction.
1 Nemeth B, Scheres LJ, Lijfering WM. Bloodcurdling movies and measures of coagulation: Fear Factor crossover trial. BMJ 2015;351:h6367.
2 Video game playing increases food intake in adolescents: a randomized crossover study. Chaput JP, Visby T, Nyby S, Klingenberg L, Gregersen NT, Tremblay A, Astrup A, Sjödin A. Am J Clin Nutr. 2011 Jun;93(6):1196-203.
3 Effects of hyperglycemia and hyperinsulinemia on circulating tissue factor procoagulant activity and platelet CD40 ligand. Vaidyula VR1, Rao AK, Mozzoli M, Homko C, Cheung P, Boden G. Diabetes. 2006 Jan;55(1):202-8.
Competing interests: No competing interests