Drugs of addiction

With news stories about a new stimulant called MDPV the news media once again focuses on addiction as a prime reason for concern. What continues to concern me is how addiction manifests itself. Dictionary.com defines addiction as "the state of being enslaved to a habit or practice or to something that is psychologically or physically habit-forming, as narcotics, to such an extent that its cessation causes severe trauma" which then beggars the question - What is severe trauma? Perhaps it might be useful to distinguish between addictive and habit-forming since we can all probably recall biting our finger nails and sucking our thumbs and at that time experienced some difficulty stopping the behaviour but noone could call that an addiction.

For many smoking cigarettes is a habit without any withdrawal syndrome yet others experience it as an acute addiction so where are we? After smoking for several decades it seems impossible to stop when cigarettes are readily available and especially when there are people close by who are smoking all the time. Placed in a situation where cigarettes are unavailable there is a craving for something which is no longer there but after several days to a week this tapers off to nothing until once again the sight or smell triggers the craving again. Stanton Peele in his book 'Love and Addiction' explores this in detail and is well worth reading for the light it sheds on this behaviour. Here for the sake of argument i make the distinction between a craving and a sickness where the sickness is the withdrawal syndrome observable by others on cessation of the drug.

The signs of opiate withdrawal are dilated pupils, runny nose eyes mouth bowels, urinary frequency, loss of appetite, vomiting, early and spontaneous ejaculation in males, muscle cramps, pilo-erection and the endless insomnia that seems to break even the most determined abstainer. Perhaps the most common reason for taking the drug is to escape the foreboding and uneasiness that seem to haunt our lives whether we take drugs or not but this isn't observable by others. Benzo-diazepines are another drug group with a characteristic withdrawal illness. Agitation, tremors, insomnia, impaired vision including hallucinations, delusions and convulsions are all observable to others. Barbiturates are similar but are more likely to involve death either through an overdose or withdrawal.

Chloral Hydrate has a mild withdrawal syndrome but what about amphetamines and cocaine. From my experience an elevated appetite and tiredness are pretty much it apart from the craving which may or may not be acute. This is the distinction i am wanting to draw. Not so much between stimulants and depressants so much although this must have a lot to do with it and what about hallucinogens and dissociative anaesthetics like nitrous oxide and ketamine. I have never experienced withdrawal after steady use of these but what about others since this is a pretty subjective view i am eager to know what others think through experience or otherwise.