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Addiction in any form is considered to be a chronic illness. Long term treatment and motivation are primary requirement to get well. Heroine causes severe withdrawal on stoppage. Due to that it is difficult to stop without professional help.
His behavior symptoms may be due to psychological complication of substance use. Intravenous drug users at high risk of developing HIV
B/C, so you need to careful for yourself also.
I would advice get him evaluated by de addiction specialist or psychiatrist
in non judgmental way, and then only take treatment related decision.
Wish you good health and all the best.
Dr Ashish Kumar Mittal