Vincent Jackson died from chronic alcohol use and the manner of his February death was "natural," according to the Hillsborough County (Florida) Medical Examiner.

The medical examiner's release comes days after the Concussion Legacy Foundation said Jackson was diagnosed with Stage 2 chronic traumatic encephalopathy, the progressive brain disease associated with repeated head trauma.

Jackson was found dead Feb. 15 at the Homewood Suites in Brandon, Florida, after his family had reported him missing five days earlier. He was 38.