The upshot of the report is that government policies which categorize drugs for the severity of restrictions have limited connection to the actual harm caused by specific drugs. For example, Ecstasy and LSD are highly restricted and regulated, though not very harmful, while alcohol, the most harmful drug, is restricted hardly at all.
In the U.S. we have a parallel circumstance. In 1970, the U.S. Congress passed the Controlled Substances Act, which created categories, called schedules, of drugs according to their potential for harm, their addictive risk, and whether or not there are legitimate medical uses. For a good cure for insomnia, try this link for details on the Act. You may need a stimulant to get through the text of the Act. Since the original passage, there has been debate regarding the validity of the placement of various drugs. For example, Schedule I, defined as the group of most dangerous drugs, includes heroin, but also marijuana and LSD. While there is no argument that heroin addiction is a destructive lifestyle and a blight on the communities in which addicts live, the case can be made that use of heroin is made much more harmful because of well-intentioned government policies. Today, it is hard to find an expert voice who will say that marijuana is a particularly harmful drug. Notably absent from the schedules of the Controlled Substances Act are alcohol and tobacco, which at the time, were not considered drugs by most people, including members of Congress.
In my view, the findings of the British experts are paralleled in the U.S. Our greatest drug problem is alcohol. Tobacco kills about five times as many people as alcohol, but smokers live entirely normal lives until about 25 years in they get life-threatening chronic illnesses like cancer, heart disease and chronic obstructive lung disease. There are almost no social harms caused by tobacco, and in fact, there are social benefits in employment and trade. Alcohol doesn't kill as many people, but destroys the user's life once consumption passes the moderate level of drinking. This leads to serious and worsening health problems, loss of employment, family turmoil and breakup, domestic and public violence, highway accidents, homelessness, poverty, huge productivity losses and treatment costs. To be fair, alcohol has some medical and social benefits. The evidence is strong that moderate alcohol use, particularly with wine, has medical benefits, though this fact does not mean that everyone should drink. In addition, alcohol has social benefits in employment, trade, and tax revenues.
The fact that alcohol is used by two thirds of adults, and that there are some health and social benefits, makes health promotion messages and policies complicated. Health communication directed at the public doesn't incorporate nuance well. Effective communication needs to be direct and unequivocal, and for this and other reasons, we struggle as a nation to educate and influence to find benefits from no more than moderate consumption while trying to block all the destruction alcohol can do.
We are soon going to face this with marijuana as well. The momentum behind legalization of that drug seems to be gaining speed and strength in states and local communities. The challenge will be to build up public precaution about the potential hazards without blocking the real or imagined benefits.