Nick Gordon claims Bobbi Kristina Brown turned to drugs to help her cope with mum's death.
According to Nick, Bobbi was a "social" drug user before the star drowned in a bathtub in 2012 following a massive heart attack caused by years of cocaine abuse.
He told Dr Phil that Bobbi's habit became "really bad" after she died, explaining:
"It's unfortunate but at the time it’s the only way we knew how to deal with what happened."