Bristol's drug and alcohol support service is the Horizons Partnership. More information can be found on their website here. They offer a broad range of support across the city in partnership with various agencies and charities. The two key agencies are Bristol Drugs Project and Turning Point. You can refer into any of the Horizons services via their website.
As part of the Keeping Bristol Safe Partnership we have a Combatting Drugs Partnership which works closely with Horizons to tackle drug use in the city.