Constant craving.

The programme examines drug, nicotine and alcohol addiction and surveys research aimed at producing vaccines against these forms of addiction. The action of cocaine on the brain is demonstrated by brainscans. The importance of dopamine to the brain is a crucial factor in addiction; lack of it can prompt dependence on substances which in themselves damage the brain's ability to produce dopamine. Mental and genetic factors in addiction are also considered. A drug to help smokers give up the habit acts by boosting dopamine in the brain and an implant to block the effects of heroin on the brain helps some addicts, although withdrawal must be endured before the implant can be given. The chemical action of this medicinal drug, Naltroxon, is explained. In theory, vaccines could be created for most addictions but the question arises as to whether prevention would be better than treatment; if, for instance, a vaccine against nicotine were produced, should it be given to people at birth or would this raise questions of civil rights?