Replicating Internship Stress-Induced Depression In China

Abstract

Many twin and adoption studies have established that both genes and the environment are risk factors for major depression (MDD). Child maltreatment increases risk for depression later in life, and stressful life events or a period of severe chronic stress precede nearly all first episodes of depression. Although more common than most other psychiatric disorders, GWAS with similar samples have been less successful than for other psychiatric disorders, so we know still very little about genes involved in major depression. Hypothesizing that to identify MDD genes, it may be useful to control the environmental factor, in 2004, Srijan Sen et al. started the Intern health study, which uses internship, the first year of residency as a stressful period of life that can be considered an environmental risk factor, as interns often have long working hours, and feel ill prepared to make life or death decisions. Indeed, the average PHQ9 score goes from 2.4 to >6, and the proportion of interns who meet criteria for depression goes from 4% before internship to 26% during internship (Arch Gen Psychiatry. 2010). Residents largely don’t seek treatment, out of fear for retribution (Journal Grad Med Educ 2010). This study now recruits >3500 residents each year in 55 Universities, and the first GWAS results will be available end of 2016.In China, a formal residency did not exist until recently, but has now started in major cities. In 2015, we contacted several major Universities and spoke with residency directors and residents themselves. We found some similarities and differences. All residents agreed that the first year of residency in China is very stress, with long working hours and high responsibilities. Residents agreed that some colleagues may be depressed, but would not seek treatment. Unlike in the US, there is no internship year - residency is focused on specialty training immediately, and the break between the end of Medical School and start of residency is only a few weeks rather than 2-3 months. To pilot a residency health study in China, the 2015 entering cohort of Peking Union Medical College was contacted to fill out the same baseline surveys, all translated into Chinese, and the same shorter surveys about sleep, stress, errors, and the PHQ9 every 3 months, to which 76 responded, an acceptable 75% participation rate (compared to 69% in the US). Data demonstrate that the PHQ9 depression rates are similar as in the US both before (4.5%) and during (22%) the first year of residency. We hope to extend this study to additional Universities in China in 2016, as these pilot data suggest that a Chinese sample may complement our ongoing US study.