Before going on to a PhD after your master's, do it only if the job you are aiming at clearly requires one, and count the mental strain before you start

Cost

Free. Look through the education requirements in the target employer's job postings, and talk once with two or three current PhD students.

What you get

The 2020 UK Department for Education study cited in §23.24 (master's) also looked at PhDs. In its words, “8% (women) and -9% (men) for PhDs”: after removing differences in family background and bachelor's results, at age 35 women with a PhD earned about 8% more than those with only a bachelor's, and men about 9% less. The study also found that a PhD lowered the chance of unemployment and of earning under 30,000 pounds (3万英镑) a year, and also lowered the chance of earning over 40,000 pounds (4万英镑) a year. Fields differ a lot: the return to a PhD in mathematics is especially low, and psychology PhDs are among the highest. For the mental strain during a PhD, look at a 2021 meta-analysis. Across 16 studies and 23,469 PhD students, about 24% in total had clear symptoms of depression (95% CI 18%–31%, the plausible range). Across 9 studies and 15,626 PhD students, about 17% had clear symptoms of anxiety (12%–23%). The studies differ greatly from one another (I² about 98%). For costs in China, follow the 2013 guideline: tuition for full-time academic doctoral programs is generally no more than 10,000 (1万) CNY a year, and the national graduate stipend is at least 10,000 (1万) CNY a year.

Notes

A dispute. The depression and anxiety figures simply combine the shares found in surveys in various countries, with no comparison to people of the same age, and the questionnaires differ. So they show these symptoms are common among PhD students, but not that doing a PhD caused them. A pooled analysis of Chinese-language studies in China found little difference in psychological symptoms between PhD and master's students, but both were higher than the national norm and the youth norm. The limits of the income figures are the same as in §23.24 (master's); treat them only as a direction. Job postings for university faculty, research institutes and some R&D positions often state that a PhD is required; if you want that road, first go through the target employer's postings of recent years. If low mood lasts two weeks or more while you study, first do the things in §3.18 (what to do first when your mood is low); if you have thoughts of suicide, call 12356 (China's national mental-health hotline), see §1.25 (if you are depressed or thinking about suicide, call 12356).

Evidence grade

B : Supported by research but without a precise number, or based on small or single studies.

Sources

1. Britton J, Buscha F, Dickson M, van der Erve L, Vignoles A, Walker I, Waltmann B, Zhu Y (2020). The earnings returns to postgraduate degrees in the UK. Department for Education. https://assets.publishing.service.gov.uk/media/5f609e478fa8f5106d1563cc/PG_LEO_report_FINAL.pdf
2. Satinsky EN, Kimura T, Kiang MV, et al. (2021). Systematic review and meta-analysis of depression, anxiety, and suicidal ideation among Ph.D. students. Scientific Reports, 11, 14370. https://doi.org/10.1038/s41598-021-93687-7
3. Liu H, Gao Y, Tuerxun N, Cabirou L (2026). More than Depression: Doctoral Students' Mental Health in China: A Systematic Review and Meta-Analysis. Behavioral Sciences, 16, 1355. https://doi.org/10.3390/bs16081355
4. 财政部、国家发展改革委、教育部 (2013). 关于完善研究生教育投入机制的意见（财教〔2013〕19号）. https://www.gov.cn/gongbao/content/2013/content_2404719.htm

Translated from the Chinese original. Original book, section 23, tip 25. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer