Willpower is probably starting to ebb from that New Year's resolution to cut down on alcohol. Why? Because you're fighting your natural inclinations: intoxication is a basic human drive. That's why children so enjoy being giddy after spinning around or rolling down a grassy bank. For adults, such pleasures are invariably guilty ones associated with being irresponsible. The reaction to scientists' invention of the "sobriety pill", therefore, was fascinating.
To some, the properties of dihydromyricetin, which can make drunk animals sober within a few minutes of ingestion, seem like a godsend. The pill is about to enter human trials but this has brought out some people's inner puritan. Surely, they claim, those who get high shouldn't be allowed to avoid the crash to earth.
What's often missed is that it is entirely normal to get high. Human beings have always sought intoxication, and always will. Nor is it just us. Tasmanian wallabies have been caught repeatedly raiding fields of poppies grown to produce pharmaceutical opium (they're not difficult to catch - once they have ingested enough opium, they run around in crazed circles). Malaysian shrews go mad for the fermented nectar of the bertam palm. Elephants happily get tipsy on fermented fruit.
The desire to get high is a by-product of evolutionary success. The pleasure involved is created by brain circuits that encourage us to do things that are essential to survival - sex and eating, for example.
In research published last year, this was extended to include less obvious tasks such as seeking out vital minerals: allowing salt-deprived rats to drink salty water activated the same gratification circuits that are hard at work when cocaine and heroin addicts have just sated their cravings.
Alcohol gives pleasure through a slightly different brain chemistry from narcotics. It is associated with the neurotransmitter known
as gamma-aminobutyric acid, or "gaba". The brain has many different receptors for gaba, each of which induces one of the various experiences familiar to alcohol drinkers: euphoria, sedation, memory loss and impaired motor skills, for instance. It might be possible to create a pill that binds only to the gaba receptor associated with euphoria and thus creates none of the negative effects. Such alcohol proxies are, to puritans' undoubted horror, under development.
Research is also aiming to reduce harm from narcotics by creating vaccines that will help those trying to kick cocaine or heroin addictions. These innovations train the immune system to respond as if the narcotic were a foreign invader.
By vaccinating an addict with a drug composed of conjoined cocaine and cholera toxin, for instance, the immune system generates antibodies
to cocaine. When it comes into contact with pure cocaine, it sequesters it in the bloodstream, preventing it from reaching the reward centres of the brain.
No one pretends that these measures are problem-free. In some trials, narcotic vaccines have led to relapsing addicts taking dangerous amounts of drugs in pursuit of a full high. Because the sobriety pill makes you feel normal but does nothing to reduce blood alcohol levels, it brings with it increased risk of alcohol poisoning and, for those who have popped a pill and consider themselves sober enough to drive, a drink-driving conviction.
However, once we accept that human beings won't stop getting high, it becomes clear that finding ways to minimise harm is, flawed or not, the responsible thing to do - whatever the new puritans say.