Re: What happened to Jennifer Lien?
There was a drug rumor about a Star Trek actor (not Lien) before "the changes in season four" but that rumor was never confirmed and that actor wasn't fired either.
It must have been Neelix. He seemed pretty addicted to leola root, using it in all his recipes. And he seemed a bit hyperactive.
Dr. Howard, Dr. Fine, Dr. Howard: For duty and humanity! --Men in Black (1934)