Did Mark Zuckerberg just lie to Congress?

Is there a causal link between social media and poor mental health?

I personally think that's a self-evident truth, but also amply evidenced by scientific research. Have you read any research, such as those collected here [0], or maybe more recent studies?

Mark Zuckerberg said to US Congress (and a room full of grieving mothers):

  "The existing body of scientific work has not shown a causal link
  between using social media and young people having worse mental
  health"

His advisors may have thought that was something they could get away with, but did they not properly research and so misjudge that?

Did Zuck just effectively lie to Congress?

[0] https://ledger.humanetech.com/

EDIT: forgot to include my main exhibit of evidence. Not doing very at this today, sorry.