TAMPA, Fla. -- The Hillsborough County (Florida) Medical Examiner said Wednesday that former NFL wide receiver Vincent Jackson died from chronic alcohol use and that the manner of his February death was "natural."

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 and after authorities had spoken with him as part of a welfare check. He was 38.

No cause of death was released at the time.

In the months leading up to his death, the former Buccaneers and Chargers wide receiver suffered from depression, progressive memory loss, mood swings, paranoia and extreme social isolation, all considered to be symptoms of CTE.

The autopsy report revealed that Jackson suffered from alcoholic cardiomyopathy, hepatic steatosis and fibrosis, esophageal varices, ascites, jaundice, remote pancreatitis, renal failure and hyponatremia dehydration, cardiovascular disease, and intoxication by ethyl alcohol -- all consistent with chronic alcohol use. The medical examiner found that he had a blood alcohol content of 0.28%.

Jackson had no alcohol-related incidents with the Buccaneers, but during the early part of his career while with the Chargers, he was arrested twice on suspicion of DUI (2006, 2009) and was suspended for the first three games of the 2010 season as a result.

The autopsy report also noted that Jackson suffered from Stage 2 CTE (Stage 4 being the most severe). CTE only can be diagnosed posthumously through a special autopsy. Jackson's family donated his brain to Boston University's CTE Center in hopes that other families could be helped by what its researchers find.

A three-time Pro Bowler, Jackson reached the 1,000-yard mark six times in his 12-year NFL career, finishing with 540 catches, 9,080 receiving yards and 57 touchdowns.

His work off the field, particularly during the latter part of his career, garnered attention.

With his wife Lindsey, he founded the Jackson in Action 83 Foundation to assist military families, and they wrote three children's books together. Jackson graduated with a degree in business management from the University of South Florida in 2016 and had opened five restaurants in San Diego, Las Vegas and Tampa.