Tuesday, January 27, 2009

Alcohol use disorder prevalence

I saw this yesterday and feared that alcoholism research was going the same route as research on psychiatric prevalence--finding implausibly high rates of disorders.

A 20% lifetime rate of dependence for men would either be false or demonstrate the uselessness of dependence criteria. Reading the press release left me confused about whether that 20% figure was dependence or the sum of dependence AND abuse.

This Join Together research summary suggests that it is the latter. (Whew! Especially since Marc Schuckit is the lead author. I'd be very disappointed if his research began to look unreliable.)

Some data points of interest about early use and disorder onset:
  • The usual age of first drinking, independently of the family, is about 15 years and has not changed much in decades. This age does not differ much for those who go on to develop alcohol-use disorders and those who do not, although an earlier onset of regular drinking is associated with a greater likelihood of later problems.
  • The period of heaviest drinking is usually between 18 and 22 years of age, and also does not differ much between those with future alcohol-use disorders and the general population.
  • More than 60% of teenagers, even those without alcohol-use disorders, have experienced drunkenness by the age of 18 years, and about 30% have either given up events such as school or work to drink, or have driven while intoxicated.
  • The period of heaviest drinking is usually between 18 and 22 years of age, and also does not differ much between those with future alcohol-use disorders and the general population.
  • Alcohol abuse and dependence often begin in the early to mid-20s, at a time when most people begin to moderate their drinking as their responsibilities increase.
An interesting point about depression and alcohol:
  • Repeated heavy drinking in alcohol-use disorders is associated with a 40% risk of temporary depressive episodes...
On abstinence vs. moderation for dependent patients:
  • Abstinence is the usual goal for treatment of dependence in the USA, although efforts to control drinking, or reduce harm, are more often deemed appropriate goals in the UK and other parts of Europe. Some studies have reported that about 20% of those with alcohol dependence were able to drink moderately without problems in the previous year, but this is often temporary, and other studies indicate that fewer than 10% ever develop long periods of non-problematic drinking.
On genetic risk:
  • About 40-60% of the risk of alcohol-use disorders is explained by genes and the rest through gene-environment associations.

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