the concept of an addictive personality is still unproven, I do however agree that many people seem to "cross addict" from one substance to another. There isalso evidence that traditional treatment may not be as effective as publisised by he treatment providers, and that many people recovering from addiction have done so purely on their own.
I do not want to give the impression that traditional forms of treatment (12 step etc) are ineffective, as they are obviously not, it's just the there is a theory in medicine that the further we are from a real cure for something, the more cures we have available. (the common cold is a good example) I would therfore propose that more investment into research of the nature of addiction both psychological and physical is the best way forward. This is sorely lacking in the UK and seems to almost exclusively be research on effectiveness of current treatments in the US.
Still a long way to go I would suggest.
Tom