In January 2019 researchers from Germany published the results of their study to examine the relationship between a vegetarian diet and mental health issues. 2,007 adults from Germany, 3,020 from Russia, and 3,038 from the USA were included in the study. In addition, 1608 university students from Germany and 12,744 China were also included. Information was collected via a self-reported questionnaire. Results showed that a vegetarian diet did not appear to be associated with mental health issues in individuals from Germany, Russia or the USA. However, a vegetarian diet did appear to be associated with anxiety and depression in Chinese students.
Lavallee K et al. Vegetarian diet and mental health: Cross-sectional and longitudinal analyses in culturally diverse samples. J Affect Disord. 2019 Jan 29;248:147-154.