Assuming this is a genuine question, thousands of businesses and lives have been irreparably destroyed. Suicide can take years to manifest after trauma. It's also worth noting that a lot of people have been temporarily propped up by government social programs, which will presumably end at some point. Once they do end, the destruction is no longer hideable and the people who have been made destitute by government mandates will have absolutely nothing.

A restaurant owner who saved their entire life to open up a business was forced to shut down for the greater part of a year with inadequate government support. Of course that causes depression and even suicide in some cases. Their life's work has been eviscerated through no fault of their own.

During the lockdown, the government's message was essentially "do not open your business by threat of enforcement action, but by the way you have to keep paying your rent/mortgage and we're going to give you a token amount of money to help".

While this was happening, governments around the world were throwing cash at banks and big business. Small businesses got screwed. As usual.

As for the specific medical reasoning, I'm no medical professional and would not pretend to know how the Australian Medical Association comes up with their claims.

If you were questioning the source, I'd implore you to post counter-evidence.