For a heroin addict, nothing is more important than getting heroin. Interpret all behaviour from this viewpoint: How can this help them get heroin. A heroin addict may steal from their own family and lose other interests and friends, since nothing is as important as the addiction. The heroin addict may sacrifice anything like family, friends, job, savings.
Dishonesty, guilt feelings and depression are common.
Uncontrolled, compulsive and disruptive behaviour may occur.