Because alcoholism is a multi-factorial psychiatric disorder, with both psy
chosocial and biochemical/genetic factors leading to its manifestation in a
ny one individual, the presence of biochemical/genetic factors alone may no
t lead to the manifestation of the disorder. There are numerous difficultie
s associated with identification of a trait abnormality in a disorder that
requires suitable socio-cultural permissiveness with distinct behavioural c
haracteristics to manifest a disorder that may not require that predisposin
g trait abnormality in order to develop. Numerous studies have been perform
ed in the past to potentially identify a biochemical or genetic trait abnor
mality in alcoholism, and not all of them have addressed significant method
ological flaws in this type of research. This review addresses some of the
difficulties inherent in this research, and aims for a comprehensive review
of the highlights of the search for a clinically useful trait abnormality.
Some series of investigations hold promise that a trait marker for a parti
cular subset of alcoholics may be developed, e.g. severe alcoholism and the
dopamine D2 receptor gene; the level of reaction to alcoholism in family h
istory-positive alcoholics; beta-endorphin abnormalities in specific family
groups of alcoholics; reduced P3 wave event-related potentials as markers
and predictors of development of substance abuse in predisposed youths; red
uced growth hormone response to apomorphine as a predictor of relapse to al
coholism in early abstinence; abnormal adenylyl cyclase activity in certain
defined subgroups of alcoholics; and abnormal platelet monoamine oxidase l
evels in subjects with a behavioural predisposition to addictive disorders.
The review concludes that while there has not yet been an identification o
f a comprehensive trait marker for alcoholism, there is hope for identifica
tion subgroups of alcoholics with consistent biological markers within that
subgroup that may well prove fruitful over time. It will then be up to a f
uture generation of clinicians to take that information and develop prevent
ion programmes that can incorporate this information to help the predispose
d individual avoid alcohol problems.