Not only will it help to improve longevity of life and help to increase the quality as well; being outside generally helps most anyone. From the crisp smells of nature, to the hustle of a city - just being outside your normal habitat can help you to forget and stay away. From hiking to boating to taking a cab to Central Park, there's many things anyone can do to distance themselves from what they're in rehab to begin with - Substances. If you can't access them and are giving all your efforts to a secondary hobby (gardening, sports, swimming) - whatever the case may be, it helps. It's low cost (and/or free - go enjoy life) and it's everywhere. Most people will agree that enjoying something that isn't in your house is a decent way to spend time. A psychiatrist also said this to me as well, so I believe it. The more you feel closer to the outdoors the more you'll form a different but healthy affinity towards something. This can be said of any hobby however. I'm just suggesting: Go outside. Get a breath of fresh air. If it's winter and it's freezing this still applies. Go get some warm clothes. Tromp through the snow like a kid. Forget life for a minute. Get healthier.