Imbalance between drug and non-drug reward availability: a major risk factor for addiction.

1. Eur J Pharmacol. 2005 Dec 5;526(1-3):9-20. Epub 2005 Nov 2.

Imbalance between drug and non-drug reward availability: a major risk factor for
addiction.

Ahmed SH(1).

Author information:
(1)Laboratoire de Neuropsychobiologie des Désadaptations, University
Victor-Segalen Bordeaux2, CNRS-UMR 5541, 33076 Bordeaux, France.

Laboratory animals self-administer most, though not all, drugs of abuse. Recent
evidence shows that with increased drug availability, most laboratory rats
develop all the major behavioral signs of addiction, including: 1) drug intake
escalation, 2) increased motivation for the drug, 3) difficulty to abstain, 4)
decreased reward function, and 5) inflexible drug use. The large prevalence of
addicted rats may suggest that they are particularly vulnerable to develop
compulsive drug use. I review evidence showing that this apparent vulnerability
results in large part from the lack of positive (i.e., alternative non-drug
rewards) and negative (i.e., costs) incentives capable of turning animals away
from the pursuit of drugs. In particular, most animals seem to take drugs and
eventually become addicted, not because drugs are intrinsically addictive, but
more likely because drugs are the only significant sources of reward available in
the laboratory. Laboratory animals would therefore represent more of a model of
high-risk human groups than of the general population. Consequently, they should
be more suited for searching factors that protect from, rather than predispose
to, drug addiction. Reconsidering the environmental background of drug
self-administration experiments in laboratory animals raises intriguing
implications for understanding the initial demand for drug consumption and the
transition to drug addiction, and for extrapolation from laboratory animals to
humans.

DOI: 10.1016/j.ejphar.2005.09.036
PMID: 16263108 [Indexed for MEDLINE]

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