There's not always a secondary. But some brain disorders (like a chemical imbalance leading to bi-polar disorders) can be very affected (either way) by cannabinoids. For some, MMJ is a life-changing saving grace. To others, it triggers psychotic episodes. I just noted the BAPD, on the off chance that she got committed, and tried to play the "oops, I was stoned" card. 19 years -- you are either an APD, have the patience of a Buddha, or she's in and out of treatment, hospitals, and jails. If she's a friend, that's an impressive amount of time to spend with someone that can be so destructive.