Was Charleston shooter on powerful mind-altering drug?

The shooter was reported to be on Suboxone, which includes these possible side effects:

Psychiatric

Common (1% to 10%): Anxiety, depression, nervousness, abnormal thinking
Uncommon (0.1% to 1%): Abnormal dreams, agitation, apathy, depersonalization, drug dependence, euphoric mood, hostility
Frequency not reported: Restlessness, irritability
Postmarketing reports: Hallucination, attempted suicide, insomnia^[Ref]

 Cop who apprehended him in February found disturbing evidence

"While the Justice Department immediately confirmed it is investigating the Charleston church shooting as a “hate” crime and President Obama chose to focus on the need for more gun control, a less-publicized aspect of the Charleston church-shooting story is the role of a powerful drug that the 21-year-old suspect was known to be using.

"The picture beginning to emerge about the shooter, Dylann Roof, is one of a young man who was into long-term and hard-core drug abuse. He was apprehended at a mall in February by a police officer who made a startling discovery." . . .

"One patient named James posted his experience with Suboxone on Mental Health Daily:

“Man this is the toughest thing to go threw [sic] period. I’m about 3 weeks into it and I feel like hurting myself. I have been threw [sic] a lot of stuff in my life but this takes the cake,” he commented.

Another, Lana, posted, “I’m going insane!!” She added, “Suboxone increased my depression, I lack motivation, I was nauseous nonstop, I gained weight. … I lost all motivation and love for life.”

Kris posted, “My doc won’t refill my prescription. So I am sitting here, restless, irritable, mood swings, feeling like I am going to f*****g snap!!!”