A recent study from a research group at Flanders University in Belgium claim that one in three PhD students are at risk of a common psychiatric disorder such as depression or anxiety, a much higher prevalence than any other similarly educated populations.
This is a striking statistic but not an overly surprising one. Being a PhD student is extremely stressful.
The pay isn’t great, the working hours aren’t set and can be long and draining, you’re in a fast moving field and constantly under pressure to deliver novel results to an audience that may have different ideas to your own. You’re never quite sure when you will reach the finish line. And when you do submit and defend your thesis, worry that it will be largely ignored and fast become insignificant.