THE EFFECTS AND IMPACT OF ALCOHOL
Effects of alcohol (1,2)
Low to medium concentration
It is now clear that alcohol has specific actions on the functions of some
brain neurotransmitters, rather than being a non-specific membrane disrupting
agent as was once thought. In particular, the effects of low to medium
concentrations of alcohol are to promote the actions of the brain's main
inhibitory transmitter gamma amino butyric acid (GABA). This leads to sedation,
ataxia and, in some cases, disinhibition.
Genetic differences in the protein sub-units that make up the receptors for
GABA confer differential sensitivity to alcohol in animals, and may contribute
to human susceptibility. The pleasurable effects of alcohol are thought to be
mediated by this action, plus the release of amine transmitters, especially
dopamine, and endogenous opioids such as endorphins.
Higher concentrations
At higher concentrations, alcohol interacts with other receptor systems. For
instance. it stimulates a sub-type of receptors for 5-hydroxytryptamine, the
5-HT3 receptor, and this may contribute to the nausea and vomiting of severe
intoxication. In parallel, alcohol inhibits excitatory transmission in the
brain by blocking glutamate receptors, and this contributes to sedation and
amnesia.
Moreover, since these receptors increase in number on chronic
administration, they are overactive in withdrawal, which contributes to the
symptoms such as tremors and seizures, and may also lead to neuronal death that
eventually results in alcoholic dementia.
Alcohol consumption and health - Facts and figures (3)
20% of the UK adult population consume 80% of the alcohol. 3% of the UK
adult population consume 30% of the alcohol.
8% to 10% of people aged 16 to 74 years of age in western countries die of
causes attributable to alcohol. The figure world-wide is 5%, i.e. 2 million
alcohol-related deaths per annum. 15% to 20% of suicides in the UK are
alcohol-dependent people. The incidence is 20 times that found in the general
population.
15% to 30% of male admissions and 8% to 75% of female admissions to general
surgical or medical wards in Britain have alcohol-related problems. 25% of all
psychiatric admissions in the Republic of Ireland have an alcohol-related
diagnosis.
Alcohol and driving (3)
At 80mg/l alcohol in the blood (the UK legal limit) the risk of a road
traffic accident is ten times what it would be if a driver has drunk no
alcohol. At 120mg/l alcohol in the blood (the equivalent of three pints of beer
approximately) the risk of a road traffic accident is 35 times what it would be
if a driver has drunk no alcohol.
Economic impact of alcohol misuse (4)
£111,963 million was spent in the UK on alcohol in 1994, i.e.
£22,800 every minute of the day.
The estimated total UK cost associated with alcohol abuse by heavy drinkers
is £2.7 billion for 1992, equivalent to approximately 0.5% of Gross
National Product. The cost to the community associated with road tragic
accidents is £250 million per year in Britain. (5)
The workplace costs of alcohol-related sickness, absences, and lost
productivity, are £700 million per year in the UK. This cost would be
reduced by up to £265 million per year if there were a 25% reduction in
drinking.
UK data on the cost-effectiveness of treating alcohol-dependent patients is
limited, but a recent American study indicated that all modes, including
residential care, were associated with benefits that far exceeded costs, some
by as much as 15:1.
References
1. Alcohol - How it affects the brain, by
Professor David Nutt, Psychopharmacology Unit, University of Bristol.
2. Alcohol Dependency - Meeting the Challenge; Tangent
Medical Education 1995.
3. Counterbalancing the Drinks Industry. A Eurocare Report
to the European Union on Alcohol Policy. Eurocare May 1995.
4. Godfrey C. The Economic Impact of Alcohol Misuse and
Abuse. In: Alcohol Dependency - Meeting the Challenge; Tangent Medical
Education, 1995.
5. Rutherford D. A lot of Bottle. Institute of Alcohol
Studies, 1 988.
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