Undertaking a PhD in any subject in any part of the world is to walk down a path like no other. It’s thrilling and terrifying in equal measure, and at the end of it, you’ll be the world’s foremost expert in the research you’ve chosen to spend 3-5 years of your life on.

However, for many people, that path to knowledge is often walked alone. Although individual experiences vary, composing a doctoral thesis is often extremely stressful. Many PhD students suffer from mental health problems, from chronic anxiety to clinical depression.

A brand new study by a team of international researchers has underscored just how common such conditions crop up in this very specific demographic. Writing in the journal Research Policy, it’s concluded that one-in-two PhD students experience psychological distress, and one-in-three are at risk of experiencing a psychiatric disorder, either over the short or long-term – particularly depression.

“Most prevalent are feelings of being under constant strain, unhappiness and depression, sleeping problems due to worries, inability to overcome difficulties and not being able to enjoy day-to-day activities,” the team, led by Ghent University, write in their paper.

The primary predictor of mental health issues was work-family conflict, where the demands of the research interfere with their family or personal life. Common factors here include work overload, unrealistic demands, unsupportive supervisors or interpersonal problems at work.

Stress explained. TED-Ed via YouTube

“The prevalence of mental health problems is higher in PhD students than in the highly educated general population, highly educated employees, and higher education students,” the team noted. A PhD student was 2.4 times more likely to develop mental health problems than those in the general population with an undergraduate degree.

The study involved analyzing the relative mental health of 3,659 PhD researchers in Belgium. Although the paper only focused on one country, it’s highly likely that their results can be replicated elsewhere.