Risk factors for depression and anxiety in doing a Ph.D.

As a follow-up to the first post in this blog, I dig a little deeper in some of the research on anxiety and depression during doctoral studies, to find “risk factors” and “correlates” that seem to often come along these depressive symptoms. I hope that the awareness of these factors (from gender to other things you can actually change in your everyday life) will help you understand why some people struggle doing a PhD, while for others it seems a piece of cake. Change what you do and put the odds on your side!

As we have seen, depression and anxiety are an increasingly common ailment of Ph.D. students. So much so that, if you don’t experience these symptoms yourself during the Ph.D., chances are somebody else around you (e.g., a colleague, or a friend) will.

The good news is that many of these studies that determined how frequent mental health issues are in the Ph.D., also investigate what factors seem to correlate (and how much) with symptoms of anxiety or depression (or stress in general). Let’s review the most common ones.

The Big Five

As it often happens when you start reading research studies on anything, each study is a bit different, measures things differently, was done on a different population… so it is hard to have a single, very accurate picture. Yet, there are five factors that appear again and again in the studies on doctoral student mental health:

1. Gender: In many of the studies I have read gender was discovered to be significantly related with depression and anxiety symptoms. For instance, in a recent study, women were about 17% more likely to be depressed than men¹, and in another around 27% more likely². Often, the effect on anxiety is even higher than on depression³. Being trans-gender or being gay have also been related even more strongly with depression (in different studies, trans were 60% more likely¹, and gay were almost 4 times as likely than heterosexuals³). Why is this? Multiple things can be at play: the fact that many academic fields are still male-dominated (and heterosexuals dominate in almost any population), which can lead to students not feeling like “they belong”⁴; or the fact that, in many cultures, women tend to have less difficulty in expressing their emotions, which is what many of the mental health questionnaires ask about (so, rather than men not being depressed, they might just be hiding it more)⁵.
2. Strong social ties are another factor that appears very often in these studies. By this I mean really close social relationships like having children (which lowered the odds of being depressed by about 35%²). In many of the studies, being married or having a stable partner also were related with lower rates of depression (in one study, 42% lower odds of depression³). It looks like having somebody to talk and support you through the hardships of the doctorate, or someone that really clarifies your priorities (as a crying baby often does), can be quite protective against the rumination and thought patters that lead to depression.
3. Economic situation is another one that comes up quite often: not surprisingly, having problems making ends meet does not help with anxiety and depression. However, the effect varies a lot from study to study, and from country to country, from 5% more chances⁶ to almost three times more likely to get depressed³. Even the economic situation of your parents seems to have this effect⁷ And the problem is, in most countries, being a PhD student is a low-pay, high-workload job. Related to this issue, how do you perceive your career prospects (i.e., will there be a good job for you after the doctorate) is also mentioned in several places as having an impact in the mental health of PhD students⁵,⁸.
4. Work-life balance. This one is not very surprising either, and it is named and measured in different ways: family-work conflict, job demands vs. job control, … People that perceive their work-life balance to be unhealthy, are more than twice as likely to be depressed¹, and experiencing work-family conflicts can also raise your odds of depression between 30-50%². High job demands (defined as “physical, social or organizational aspects of the job that require sustained physical or mental effort”) also seem related to depression (60% more likely²). Conversely, having high job control (of your work environment, pace of work, timing of breaks, etc.) seems to lower the chances of depression by about 40%².
5. Supervisor relationship. This is the one many of you were waiting for. Researchers have dedicated a lot of effort to study this factor from different angles, like the prior expertise of the supervisor, the supervisory style, leadership style… However, the results here are rather heterogeneous, and their importance varies a lot⁸. People who perceive their supervisor as not providing mentorship, support, or emotional impact, were 50% more likely to be depressed in one study¹, while in some other research, having an “inspirational” supervisor lowered the odds of depression by about 10%². In the same study, having a “laissez-faire” kind of supervisor raised the odds of depression/anxiety symptoms between 4-8%. In general, this issue of the supervisor style is quite difficult to tackle, as it seems to be also very cultural, and very personal (some studies mention that the important thing is that supervisor and student styles are compatible). I will dedicate a separate post to this issue alone.

There are plenty of other factors that have been studied, but either their change in odds is small⁹, or there is not enough agreement about them across studies. There is also the issue of whether these factors are causes or effects. When reading this, one should bear in mind the old adage: “correlation is not causation”. Most probably, the relationship between depression and these demographic and contextual factors is quite complex, with confounding factors and feedback loops. The way I see it: the Ph.D. is a highly uncertain, intense, ill-defined process where often long stretches of time pass without any meaningful feedback about whether you’re making any progress. Hence, it is crucial to have a variety of social (and economic) support to remind you that you are a worthy human being (and to lower the stakes of such huge effort).

But wait, you may say: why are you telling us about these risk factors, if they are all things we have little control about? It is not like we are going to have kids or change gender just to protect ourselves from depression. It is true that these demographic factors are the most studied so far, probably because they set some kind of baseline, your starting point for the odds of being depressed. But, once you know this starting point, this is when the fun begins…

What can you actually do?

One interesting thing about many of these studies on risk factors for anxiety and depression, it that they run these regression models on multiple factors, which includes some measures of how predictive they are. For example, some paper² might tell you that their R-squared was 0.2, meaning that their model (taking into account supervision, gender, and several other things) explains only 20% of the variance of the data. That also means there is an 80% of the variance (read: whether you get depressed or not) that must be due to other things: personal factors, individual circumstances and events, etc. This is compatible with the arguments of many positive psychologists, which say that our happiness is a composite of genetic factors (about 50%, according to some accounts), our current circumstances (10%), and an ample 40% for what they call “intentional activity”, i.e., things we can actually do to change our happiness levels ¹⁰.

So, has science also studied what Ph.D. students can do to avoid depression and anxiety? Yes. Kinda. Truth is, the evidence on these is normally from smaller, non-representative populations (e.g., there is a ton of studies on just psychology doctoral students). Thus, there are not big guarantees that the results will apply to you. In any case, here are a few ideas:

• Sleep. Having healthy sleep habits is one of the most powerful correlates against depression across studies. And it maybe the one that appears most consistently across the studies I’ve read, both when studying stress ¹¹,¹²,⁵ and depression¹³ of doctoral students. Hence, if you found in my first blog post that you might be at risk of depression, and you see that sleep can be a problem for you, maybe trying to fix your sleep hygiene¹⁴ is the first thing I would try. If just fixing your sleep hygiene does not cut it, I’ve had quite good results with progressive muscle relaxation exercises, but you can also look around in the web for other techniques, or go to a sleep therapist.

• Social support. This is the other big, consistent contributor to avoid depression across studies ⁵,¹²,¹⁵, as already hinted by some of the other factors mentioned above. One might think that our social circles (i.e., how many friends or acquaintances we have) are not really under our control. However, there are things one can decide to do, like seeking help (one study⁷ found that help-seeking behaviors are relatively rare among depressed students, only about 30%), or joining a writing support group⁸, if your university has one. Heck, just heading out for a social evening with friends or colleagues can take you out of your rut if you do it wholeheartedly (even if it is, of course, the last thing you want to do when you are in a depressed mood).

• Exercise. This is another well-known one. However, from the studies I’ve read the effect is not always clear: in some studies it is found as a protective factor against psychological ill health¹⁶, in others it is not significant¹², while in others it is correlated with higher stress! (although the authors argue that this is due to students already using exercise as a coping strategy against the stress that is already there)¹¹. In general, I think it is safe to assume that being in good physical health makes you less prone to falling into depression⁵,¹⁷, so keeping some exercise routine, eating healthily¹⁶, etc. is probably a good idea.

• Mindful acceptance. Now we come to the less-well-known ones. I was quite surprised to find some studies looking at this trait in students, and finding very large effects or correlations with lower perceived stress (more than twice as much as the sleep hygiene in one study¹², and also found significant in others¹⁸). Despite the new-agey name, this is not to be confused with practicing mindfulness meditation (which was not found a significant predictor in some of the same studies, once you control for this acceptance trait¹²). Looking around, I found definitions like “experiencing events fully and without defense, as they are”¹⁹, or “… one lets go of judgment, interpretation, and/or elaboration of internal events, and makes no attempt to change, avoid, or escape from the internal experience […] not to be confused with passivity or resignation”²⁰. While this might look like a fixed personal trait (you either accept stuff, or you don’t), there seem to be ways to train it²¹. Another topic to dig deeper in a later post…

• Cognitive reappraisal. Loosely defined as reinterpreting an emotional episode²², this kind of mental technique was found to correlate with lower stress in some of the studies on doctoral students¹², but was not found significant in all of them¹⁸. Again, I make a mental note to dig deeper into this one, and see if there are easy practices or habits to develop it.

Put the odds on your side

In summary, it seems that there are a few demographic and contextual factors that seem to be related with higher chances of depression and anxiety - but while they seem to be cumulative, they are not ultimately decisive. Everything in life is a bet, so for this one:

• If you are a Ph.D. student, it is probably good to know your base chances, given the factors above… but also to know what you can do to prevent it (or at least put the odds on your side). Along with the diagnostic tools we saw in the first post, this gives you a basic toolkit to see how you’re doing, understand that many in your position have had similar trouble, and do what you can to help yourself or seek help.
• If you are thinking of starting a Ph.D., maybe take a look at these factors. If you tick many of the “bad boxes” above… this does not necessarily mean you shouldn’t do it. Diversity is one thing we need in many fields, science included. But rather, understand that it may get difficult at times, that you need to brace yourself, be especially careful in the preventive side and go for it if that’s what you want!
• If you are a supervisor (or a university decision-maker), you may want to check with your students: what is their economic situation? do they have a social circle to support them? are they sleeping? You cannot take many lifestyle choices for them, but there are things among these factors that you can influence (maybe rethink that “laissez faire” strategy, if that’s your advisor style).
• If your are friends or family with a Ph.D. student, you can also do a quick factor assessment, and be especially attentive if the odds look bad; check in with them from time to time, get out and spend some quality time with them. As you saw above, that alone can go a long way. Telling them about these studies probably won’t hurt either.

Despite the depressing tone of all this, do not despair! I also see every day doctoral students that are curious, engaged, having a blast learning to be researchers. Knowing that other, darker paths exist, and knowing your odds, is just a start towards avoiding them. Let us see what other things we discover to keep ourselves on the bright side of science.

• Wellbeing
• Depression
• Anxiety