henry copeland:

Variations in Facebook Posting Patterns Across Validated Patient Health Conditions: A Prospective Cohort Study. - PubMed - NCBI

Significantly correlated language topics among participants with the highest quartile of posts contained health terms, such as "cough," "headaches," and "insomnia." When adjusted for demographics, individuals with a history of depression had significantly higher posts (mean 38, 95% CI 28-50) than individuals without a history of depression (mean 22, 95% CI 19-26, P=.001). Except for depression, across prevalent health outcomes in the sample (hypertension, diabetes, asthma), there were no significant posting differences between individuals with or without each condition.
- www.ncbi.nlm.nih.gov