I have been told many times that stress is a leading cause of acne. Up until now, I have blindly accepted this as truth, since it has been printed in several magazines and I have been told this by many people whose opinions I respect. However, as an enlightened SC 200 student who has learned to be more critical of so-called “fact,” I decided to investigate the correlation between stress and acne to see if there is any valid scientific evidence to support the claim that stress causes acne.
I came across this study, which involved 22 college students, and found that “increased acne severity was significantly associated with increased stress levels.” The study appears to be well-designed, as it controlled for some confounding variables such as “changes in sleep hours, sleep quality, diet quality, and number of meals per day.” However, there are still other confounding variables that could be affecting the results, such as genetic factors. And, it is possible that this correlation is due to reverse causation. It is quite plausible that an increase in the severity of a student’s acne causes them to become more stressed. In addition, since this was merely an observational study, and not a randomized experiment, we cannot say that it proves that stress causes acne, because as we know, correlation does not equal causation. Even so, this study provides evidence that is consistent with the notion that there is a correlation between stress and acne.
Further research led me to this study, which explored a possible biological mechanism that could explain the link between stress and increased acne in adolescents. Specifically, researchers wanted to know whether increased sebum production could explain this association. To do this, they studied 94 students with a mean age of around 15 years old, and tested whether “stress is associated with increased acne severity independent of, or in conjunction with, increased sebum production.” What researchers found was a “significant association between stress and severity of acne,” however, they did not discover a link between increased acne and increased sebum production. Again, this was an observational study, and relied on self-reports by participants, which are not always trustworthy since we know that human intuition is lousy. However, the results can still serve to support a correlation between acne and stress, even though they do not provide a biological mechanism to explain this link.
What I am able to conclude from my research is that there is evidence to suggest a correlation between increased stress levels and increased acne. However, a randomized controlled experiment will have to be performed to provide evidence that stress causes acne. Unfortunately, such a study might be unethical because it could be considered inhumane to purposefully expose participants to stress. For now, we can conclude that, since stress may be a factor of increased acne, we should try to avoid it as much as possible. In any case, avoiding stress can only be beneficial, not harmful.
(As a side note, this blog is part of a three-part series in which I explore factors affecting acne. You can find Part 2 here and Part 3 here).
Overall the study was well conducted but I don’t recognize other hypothesis such as an alternative hypothesis being rejected or null hypothesis being considered. Now I know there are many other studies of stress and acne but third variables also have to do with it such as family related problems.
I think this is a very common problem and one that I don’t need science to agree with. I agree with some of the comments above that it would be helpful to look at third variables. I think a lot of things come into play when we talk about this problem. I believe this problem could be caused by genetics, skin type, age, race, ect. This is a great topic but I think it is worth looking into the other variable causes. Good job!
I can personally attest to the notion that acne can increase in severity with stress and I too have read many different magazines and online articles citing the same thing. Hormones are known to directly contribute to acne severity so I wonder if there are any studies out there that explore whether or not increased stress causes increased hormone levels. That would surely establish a stronger connection between stress and acne. Additionally, I think your observation that because it was an observational study and not an experiment you cannot establish causality was astute. Who knows, before taking SC 200 you probably would’ve just saw that study as enough to establish causality; I know I would have!
The common problem among us teenagers today! I like that you pointed out to remind us that correlation does not equal causation. I think reverse may be possible but it all depends. Also, there could be a third variable like, genetics, or family related problems. I guess further studies will have to be conducted.