The authors show increased depression risk in the 90 days PRE-exposure (before starting treatment). To me, the authors seems to have dangerously misinterpreted

The authors show increased depression risk in the 90 days PRE-exposure (before starting treatment). To me, the authors seems to have dangerously misinterpreted the data. It could easily be the case that a depression diagnosis leads to seeing a psychiatrist and deciding to treat their underlying ADHD with methylphenidate. How could being about to go on methylphenidate in the next 90 days possible be the cause of depression???