Carl Galvin had volunteered for the Chorley and Preston Headway charity for five years before his sudden death on April 17.
Last Friday, an inquest at Preston Coroner's Court heard how the 36-year-old had died following a night drinking vodka and cans of strong cider with a friend.
Coroner Sian Jones ruled the cause of death as 'misadventure' after potentially lethal doses of ethanol and methadone were found in his system.
He had begun volunteering with the Headway charity after suffering his own traumatic brain injury in 2011, and was described as being 'enthusiastic' about the support services the charity offered.
But evidence given at the inquest also heard that Carl had 'an alcohol dependency', had reached out to mental health services for support and had taken methadone, despite never having been prescribed the drug by his GP.
Laura Brown Assistant Manager and Volunteer Coordinator, Headway Preston and Chorley said: "Carl was a valued member of our charity and was always willing to lend a hand to help others.
"He was involved with numerous projects over the years and enthusiastic about the services Headway Preston and Chorley delivered to our local community.
"We were shocked and saddened to hear about Carl’s death and our condolences go out to his family and friends, we will miss him terribly."
It was also ruled that Carl's death was linked to fatty liver disease and that a toxicology report showed alcohol levels were four times the drink-drive limit.
Carl Galvin’s family, who attended the inquest, declined to provide any further comment.
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