The lessons of Alex Norton's heroin admission

And while great efforts have been made in recent years to change public perceptions, that label retains an umistakable moral, rather than medical, dimension.

Any pity for a drug user with a wretched life is paired with a confidence that such a life is the product of choices we ourselves would never make.

Mention the so-called "Trainspotting generation" of former heroin users now approaching old age, and someone like Alex Norton is probably not who most people would picture. This may be in part because the actor's best-known character, DCI Matt Burke in Taggart, is concerned with upholding the law rather than breaking it, but more likely it is because of his status a successful and respected public figure.

This jars with the common assumption - supported for some by statistics showing how many Scots addicts remain "parked" on methadone perscriptions - that hard drugs condemn the user to a dead-end life in which the next fix is all that matters.

Norton says that after experimenting with heroin while preparing for a TV role, he "had the good sense to walk away". It might seem like a statement of the obvious, but by attributing his escape from addiction to his own responsible choice, rather than luck, biology or broader life circumstances, he serves to perpetuate the idea that those who succumb to drug addiction are somehow deficient in character, either too stupid to understand the consequences of their actions on themselves and those around them or too feckless to care.

It's a contrasting sentiment to that which is repeatedly and articulately expressed by Russell Brand, probably the UK's most famous former heroin addict and a determined campaigner for change to society's approach to drugs.

Brand has made clear on many occasions that he does not see himself as superior to those still living the life he was fortunate enough to escape, and this makes his critics uncomfortable.

Witness the number of times he is gratuitiously described as "former heroin addict Russell Brand" in articles about his political views, and thereby defined by his historic mistakes rather than the enormous day-to-day achievement of staying clean.

It's one thing for a rich celebrity to profess empathy for a marginalised group, but quite another for Brand to meet addicts living in sordid conditions while making a documentary and declare that the temptation to stick around and have a fix with them is still strong. These people are not "others" to Brand.

It seems unlikely Norton will be similarly stigmatised for his confession, given that his account serves to confirm rather than challenge the view of addicts that prevails in the UK.

David Cameron last month rejected Liberal Democrat calls for a radical rethink on drug policy, at the centre of which was a desire to view addiction as a medical issue rather than a criminal choice that must be punished, but it's vitally important that the social dimension of drug use is acknowledged too, and action taken to ensure the non-addicted life is worth living.

Both Brand and Norton endured struggles and losses in their early lives that undoubtedly made them more vulnerable to becoming involved with drugs, but both also had opportunities to forge successful careers in the entertainment industry.

Not only were financial security and public acclaim within their reach, but the means to achieving these was pretending to be someone else - surely an enviable opportunity for anyone who doesn't particularly enjoy being himself.

While a medical approach to addiction would be a step in the right direction, no doctor can prescribe the protective factors many of us take for granted, such as a home in a safe community, a job that pays a living wage and supportive family and friends.

We must not pretend that choices made by those in the most difficult of circumstances are not, in reality, significantly constrained.