Drug addiction and law: a brain perspective given by Dr. Hans Crombag
On Wednesday 14th November, as a part of a series of events organised by Sussex Students for Sensible Drug Policy, Dr. Hans Crombag, assistant professor in the psychology department, discussed the psychology behind addiction and drug policy in the UK.
The talk focused on the long-standing debate of responsibility in drug addiction. Many reiterate the well-known social determinants of addiction, such as poverty, to mark the cause of drug abuse as external. For example Russell Brand brought this issue into the spotlight when speaking to MPs earlier this year. Whilst others still advocate that addiction is a failure of decision-making.
Although there are exceptions, such as Gene Heyman’s position explored in ‘Addicton: A disorder of choice’, the majority of experts in neurobiology now hold the view that addiction is a disease. Vast amounts of research, funded by the government, have focused on investigating how addiction is manifested in the brain as well as genetic differences that could explain why some who take drugs do become addicted, when others do not.
Dr. Crombag stressed that across a range of studies, definitive brain changes as a result of addictive drug taking have been found. Recreational drugs act on the reward pathways of the brain; the areas that are responsible for generating pleasure from natural human behaviours, such as eating and sex. After taking a drug, brain pathways ‘learn’ to respond more to this drug when it is taken in the future. This ‘sensitization’ is observable by growth of existing neurons in these pathways.
The Medical Research Council’s Addiction Research Strategy investigates the causes, effects and treatments of drug addiction, both social and biological. One faction of this initiative is the GABA research cluster at the University of Sussex.
GABA is a neurotransmitter involved in the learning of cues associated with drug taking in the reward pathways of the brain. For example the sight of a syringe may act as a cue for a heroin addict’s want for that drug. Researchers at Sussex are using rats to investigate how GABA receptors contribute to addiction, as well as genetically determined differences that may make some individuals more susceptible to addiction.
A recent finding by this group showed that there are 2 types of ‘a2’ GABA receptors. Individuals with the risk type of receptor are more prone to cocaine abuse than those with the normal type. Our genetic makeup determines which one we possess, supposedly giving some individuals a predisposition for addiction, before they have even taken a drug.
Many studies have found evidence for similar genetic factors in addiction and impulsivity, but as yet, neuroscientists have been unable to pinpoint a singular genetic source of susceptibility.
Evidence has clearly shown that addicts are not making choices with the same psychological framework as a healthy individual, yet the status of addicts in courts suggests that authorities outside of research labs hold a different view on responsibility in addiction.
Behaviour of magistrates is often indicative of an implicit belief in addicts’ responsibility for their actions. In one investigation, Dr. Crombag and a student asked magistrates to estimate the sentence of a shoplifting crime, given the profile of the offender as a typical addict; impulsive and lacking control of behaviour. Astonishingly, when the perpetrator was labelled with a behavioural disorder, involving exactly the same symptoms that were described for the addict, the sentence given was decreased.
Since the domains of health and law are the spheres in which addicts live most of their lives, a coherent position between authorities in these areas seems crucial. However the issue of addiction is subject to the lack of consistency that often follows between more recent scientific understanding and the slower moving attitudes that underlie law.