Credit: Joey Foley/FilmMagic

Corey Haim died of "natural" causes, the Los Angeles Department of Coroner confirmed in a brief report released on Tuesday. Autopsy and toxicology results show that drugs play "no significant contributing factors" in the actor's death at age 38.

The coroner lists three specific causes of death: pneumonia, "diffuse alverolar damage" (damaged air sacs in the lungs) and "hypertrophic cardiomyopathy with coronary arteriosclerosis" (plaque build-up in blood vessels and the heart.)

Haim died on March 11 at age 38 after collapsing in the L.A. apartment he shared with his cancer-stricken mother, Judy.

A month after his death, California authorities revealed that the Lost Boys star had obtained over 550 prescription pills -- Valium, Xanax, Vicodin and Soma included -- illegally. In 2007, he told Larry King that he had an "addiction to pretty much everything. I have to be very careful with myself."

But in his last year of life, Haim was "in the best frame of mind that he's ever been in," pal Corey Feldman said recently. Feldman praised Haim's caretaking of his sick mother. "He's been there for her, taking care of her, being responsible."

Haim was laid to rest his hometown of Toronto, Ontario on March 16.