Tiktok or Treatment? The causal effect of high-speed internet on the use of mental health medications

In recent years there has been a large decline in the mental health of adolescents and young adults. Research in psychology and health economics points toward the rise of digital media use as a likely contributor. However, little research has been done investigating its effect on the treatment of mental illnesses. We leverage the roll-out of fiber optics to investigate the effect of high-speed internet of the use of mental health medications for people ages 12-25. Using a continuous Diff-in-Diff approach to obtain causal estimates, we find a decrease in the use of antidepressants and anti-anxiety medications, driven by people ages 18-25. We also find increases for ADHD medication for men and anti-addiction medications for women. We interpret these results as changes in the demand for mental health medications.