depression rate between 6-16 in China — 2% or 20%?

Snippet from the press conference of National Health Commission of China, Dec. 25, 2024 (full transcript in Chinese available here). The reporter inquired the credibility of data related to mental psychology circulating on the Internet.

(Xie Bin, Party Secretary of Shanghai Mental Health Centre)

[There has been] rumours that the prevalence of depression among teenagers has reached 15%-20%. According to the results of epidemiological surveys by authoritative institutions, in fact, the prevalence of depression among adolescents in China is only about 2%.

So which number is true? Guokr has the story (in Chinese here). The difference is told by the details of the experiments, and the delicacy in paraphrasing the data.

2%

The “2%-depression rate” comes from a 2020 paper (Li and Cui et al), which conducted national-scale psychiatric epidemiological survey for children and adolescents. The paper’s data is reliable— does apply sufficiently rigorous sampling methods to arrive at its data and conclusions. Basically, the research team first surveyed 73992 sample participants using The Achenbach’s Child Behavior Checklist (CBCL) (i.e. questionnaire), then had qualified psychiatrists to conduct diagnostic assessment by watching interview video clips and give out ratings.

One of the paper’s many results showed that 1445 individuals identified Major Depressive Disorder (close to 2.0%, as shown in Table 2 of the paper).

20%

The depression rate around 15~20% are more prevalent. Many, many major and authoritative reports arrive at the number. For example,

The Report on the Development of China’s National Mental Health (2021-2022), led by the Institute of Psychology of the Chinese Academy of Sciences, mentions that 14.8% of China’s adolescents may show some degree of depression. The data was obtained by analysing 30,746 valid questionnaires from people aged 10 to 16 in China.

so…

Data is accurate, the paraphrase of these data brings in misunderstanding and bias.

The main reason for the discrepancy between the two types of data is the difference in survey methodology: the higher data of ‘15-20%’ use scale screening, while the lower data of ‘2 per cent’ use scale screening + face-to-face interviews.

The 15-20% result come from surveys, which are typical descriptions of depressive symptoms, and the responses of the respondents provide insight into their depressive tendencies. Therefore, it’s inaccurate to refer to the 15-20% results gauged by surveys as the prevalence of depression—the key is, there is no distinction between what is being investigated, whether it is a mood, a state, a symptom or a disease.

On the other hand, the “2%” narrative’s issue is that it lost explanation of the details: for all aged between 6-16, the prevalence of depression among children is inherently lower than that among adolescents.

What’s worse, the 2% lost count of students aging between 17-22—high school students, especially seniors, are predictably bound to have more severe depressive symptoms, and college freshmen also have problems adjusting to their new environment and develop depressive tendencies in the very age range of 17 to 19 that the study failed to cover.

To conclude,

“15-20%” is the prevalence of depressive symptoms in Chinese children and adolescents, or the percentage of the population at high risk of depression.

The prevalence of major depressive disorder among children and adolescents in China is 2%, and the prevalence of depression among older age groups is relatively high, at 6 to 7 % for the 15-to-16-year-old group.

reference

Li, F., Cui, Y., Li, Y., Guo, L., Ke, X., Liu, J., Luo, X., Zheng, Y. and Leckman, J.F. (2022), Prevalence of mental disorders in school children and adolescents in China: diagnostic data from detailed clinical assessments of 17,524 individuals. J Child Psychol Psychiatr, 63: 34-46. https://doi.org/10.1111/jcpp.13445