Addiction (1993) 88, 179-181

WHAT I WOULD MOST LIKE TO KNOW

What are the rules of thumb for avoidingproblem drug use?

REGINALD G. SMART

Addiction Research Foundation, 33 Russell Street, Toronto, Ontario M5 2S1, Canada

Under the generous auspices of the editor severalpeople have asked the Addiction fairy godmotherfor answers to questions they were most con-cerned about. When given this opportunity theytypically asked 'questions that would give anyfairy godmother a great deal of trouble. Myquestion is in that vein and asks at what levels, ifany, can drugs be used safely and without prob-lems? This question arises partly from myinterest in 'rules of thumb', which are about easymethods to avoid trouble. If you have enoughgood rules of thumb most trouble can beavoided. The nutrition field abounds with theserules of thumb, e.g. eat no more than two eggs aweek, have no more than 30% fat in the diet, eatfood from all major food groups every day. Iassume these rules have been the result of exten-sive nutritional research programs as that is theonly way to make rules worthwhile. Once wehave good rules of thumb they are valuable inprevention efforts. They represent a shorthandform of solid professional advice that everyonecan use effectively and remember. Rules ofthumb should tell what is the minimum level ofdrug use to lead to problems.

Unfortunately, the addictions field has veryfew comparable rules and all seem to be aboutalcohol use. There is Anstie's rule going back to1870 which specifies the taking of no more than35 g of absolute alcohol per day to avoid prob-lems.' Also, we have the rule from the drinkingdriving field which specifies no more than onedrink per hour to avoid intoxication. Eventhough we have some rules of thumb for alcohol

they are not well researched and are based moreon clinical judgement, cautious guesswork, andintuition than on detailed research. Even in thealcohol field the rules are few. We have no rulesabout what consumption levels will avoid acci-dents other than driving or such problems asdomestic violence, job loss, or psychiatric symp-toms such as depression.

What we need in both the alcohol and drugfield is more research establishing levels of socialand psychological problems after a variety oftypes of use. A beginning for alcohol has beenmade by Sanchez-Craig & Israel̂ who studiedproblem drinkers in a preventive treatmentprogram. They found that "an average consump-tion of four drinks on an average of threedays/week, was the pattern that best differenti-ated the phase of drinking that was problem-freefrom the phase at which the onset of problemdrinking was recognized". There were still somemisclassifications at the level selected as 'best'.Also, the type of alcohol-related problem and itsseverity was not specified. Problem drinkers werefree to define problems in their own way. Weneed research that establishes what level ofdrinking leads to particular problems. It wouldalso be useful to establish how long drinkingpatterns must be maintained to create problemsand how different beverage types may lead toproblems.

Similar difficulties exist in evaluating howmuch consumption leads to a higher risk of livercirrhosis. Lelbach' has shown that 14% of alco-holics drinking 160 g or more of alcohol daily for

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eight years got liver cirrhosis. However, no alco-holics got cirrhosis who drank heavily for lessthan five years. Some alcoholics get cirrhosisafter drinking 80-160 g per day,''^ however, wedo not know how long such drinking must bemaintained. A good rule of thumb for potentialor early alcoholics to help them avoid cirrhosis isdifficult to establish, except for drinking less than160 g per day for less than eight years. We needmore research on establishing risks for cirrhosisand less serious liver diseases such as fatty liverat different consumption levels. We also havelittle data on how various alcohol-related cancersor cardiovascular disease relate to levels of con-sumption and what the safe levels might be.

It is interesting to see how two different re-search traditions have developed, one in thealcohol field and one in the drug field. In thefield of addiction or dependence on illicit drugsthere are no useful rules of thumb for avoidingsocial or psychological problems. Considerableresearch on dose-response relationships has beendone for many drugs but the responses studiedare physiological in nature and not of a type thatwould be used much in prevention programs.We have little good data on how much or whattype of illicit drug use leads to any problems,even drug-related accidents. We cannot specifyhow much cannabis use leads to what social orpsychological problems although this drug hasbeen studied for a very long time. A WorldHealth Organization group' found that daily useof cannabis was associated with problems butmade no clear finding for other levels of use.Only 1-2% of young cannabis users take it dailyand it is difficult to believe that problems do notarise for some users after infrequent use. About8-10% of patients at the Addiction researchFoundation have cannabis as a primary problem.However, we are uncertain how much cannabisuse, which pattern of use, or what type (mari-juana, tobacco, hashish, hash oil, etc.) led tothose problems. It would be very useful to havea well researched rule of thumb for cannabiswhich is still the most popular drug in manyparts of the world.

We also need more information about prob-lem generating levels of use for drugs such asheroin, cocaine and its 'crack' form. Some mediareports suggest that crack is addictive after thefirst smoke, but this appears not to be the case assome crack users can smoke it infrequently with-out addiction.^ We have research showing that

cocaine and crack use by expectant motherssometimes leads to addicted babies or to otherneonatal problems.' However, the problem doselevels are not understood.

With some drugs, too, there are issues of typeof delivery, e.g. whether by ingestion, sniffing,smoking or injection. Much clinical judgementand some research shows that injection use ismore addictive than other means, but cocainesniffing and crack smoking may be equally addic-tive. Issues also arise about the frequency of use.Probably daily use of cocaine and heroin indicatethat addiction or dependency have occurred,however, good research on this is difficult tofind. Some, but probably few, users can takedrugs such as heroin and cocaine daily withoutbecoming addicted^"'" but we are not sure forhow long. No real start has been made on re-search specifying the routes of administrationand levels of use of illicit drugs which lead tovarious problems. Most of us could state a fewrules of thumb based on intuition and clinicaljudgement, e.g. avoid injecting drugs, do not useany drug daily, but how valid are they?

One rule of thumb about drugs which is oftenbeing used in North America is "Just Say No".Although this rule will work for some potentialusers, for others it is like saying that the only wayto avoid traffic accidents is not to drive. Manypeople do say yes to drugs and for them weshould eventually be able to specify safe, non-problem levels of use. For some drugs and someindividuals there may be no level of use withoutproblems, but a large research program is neededto be sure. Even if we could establish that thereis no safe level of use for recreational drugs thatwould be helpful in prevention efforts.

Probably there is little interest in safe levels ofuse for illicit drugs because of legal aspects.Many people assume that if a drug is illegal thatis enough to justify a total sanction against anyuse. A more realistic public health approach is toadmit that some people will use drugs and try toprovide them with the best advice on how to doit without problems. Recognition that harm re-duction and harm minimization are viableapproaches is growing in many countries." Insome countries we provide needle exchanges andinformation on safe injection practices. It is asmall step to eventually provide information onsafer routes of administration and less risky levelsof drug use. However, a large, ambitious, re-search program is needed before we can do this

adequately. For that program we may need theAddiction fairy godmother and all other fairygodmothers to magically provide the necessaryfunds.

AcknowledgementThe views expressed in this paper are those ofthe author and do not necessarily reflect those ofthe Addiction Research Foundation. The authorwishes to thank Patricia Erickson and RobertMann for many helpful comments on thismanuscript.

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