The Science of Impulsive Behaviour

People who are impulsive tend to act before thinking. There are many varieties of impulsivity from the premature expression of behaviour before sufficient information is gathered (‘reflection impulsivity’) to the tendency of accepting small immediate or likely rewards as opposed to larger but delayed or unlikely rewards (‘choice’ impulsivity). It is also on occasion associated with aggression. In conceptual terms it is helpful to categorise impulsivity into ‘stopping’ and ‘waiting’ subtypes. In the former case this is assessed by the inhibition or cancellation of a response that has already been started. This is different from ‘waiting’ impulsivity which is best described as a dislike or intolerance of delayed rewards.

The Genetics of Tobacco Use

Although there are a number of treatments available to help people stop smoking (the most
common being nicotine replacement therapies, such as patch and gum, and varenicline in the UK),
these are only moderately effective. While they can double the chances of long-term abstinence
from smoking in those attempting to quit, this is against a very low basic success rate. Therefore,
most smokers (even those taking medications to help them stop and receiving good behavioural
support) who attempt to stop eventually relapse to smoking.

MDMA ‘ecstasy’ and new designer drugs

3,4 Methylenedioxymethamphetamine (MDMA or ecstasy) was first synthesised and patented in 1912 as a precursor of other pharmacologically active compounds by the E. Merck company in Germany. It was examined by the US military in the 1950s, presumably as a chemical warfare agent since it is chemically related not only to other amphetamines but also mescaline. However the first report that it was psychoactive in humans was a paper in 1978 by Shulgin and Nichols. It rapidly became a well known ‘designer drug’; that is a compound with a chemical structural and pharmacological similarity to existing and illegal recreational drugs but, by being novel and not specifically listed, had escaped legal control. In 1985 the US Drug Enforcement Agency (DEA) classified MDMA as a Schedule 1 drug due to its high abuse potential and lack of known clinical use. The drug rapidly became illegal in most other countries but despite this its popularity surged often being taken at ‘rave’ or ‘techno’ dance clubs and parties. The peak of use came in the late 1980s and 1990s and a recent survey has suggested a marked decline in its popularity.