Philip Seymour Hoffman left behind two private diaries that revealed his struggles with substance abuse and attempts to stay sober.
The Oscar-winning actor addressed his "demons" and attempts to stay clean with Narcotics Anonymous meetings in numerous hand-written entries.
Multiple sources familiar with the contents of the diaries revealed to NBC News that some of the entries appear to have been written while Hoffman was receiving treatment.
Some entries are apparently hard to read, with sketches and handwriting becoming more illegible as it goes on—suggesting that Hoffman may have relapsed while writing them.
"It's stream of consciousness and difficult to follow," one source told the news organization. "In one line he refers to 'Frank who always owes money' and on the same page he writes about a 15-year-old girl from Texas."
A second source explained, "It seems he did at least part of it in rehab. It definitely contained some soul-searching. But there is also a fair amount of rambling that doesn't make sense."
Hoffman's journals also were said to be strewn with references to past drug deals.
The two diaries are small—with one measuring about 6 by 8 inches and another approximately 7 by 9 inches.
Hoffman passed away at the age of 46 after an apparent drug overdose.
49 full bags of heroin, 23 empty bags of heroin, four bags of white powder believed to be cocaine and various prescription drugs were found in his apartment.
(E! and NBC are part of the same NBCUniversal family.)