After my failed marriage to an unmedicated nutjob, I now believe that a candidate spouse should be vetted by friends and family. After I divorced her, family and friends asked why I put up with that for so long!
Oh, the second time around I did! Because they admitted to having misgivings about #1, so I let them all vet #2. And they all loved him! But no one knew about the mental illness streak in his family, not even me.