Addiction to drugs vulnerability

Abstract

A challenging problem in the research on drug addiction is to understand why some subjects became addicted to drugs while others do not. Most studies have focused on psychological and social risk factors, but the investigation on the mechanisms underlying the individual variability in responsiveness to drugs of abuse suggests that a differential sensitivity of the central nervous system might be an important factor. Preclinical and imaging works also suggest that a decrement in regulatory elements of neurotransmitter systems such as dopaminergic, glutamatergic and opioidergic might have a role in the vulnerability to drug addiction. These works also have revealed that chronic drug selfadministration results in neural adaptations that render the brain even more vulnerable, and with a great proneness to relapse. However, with the exception of cases of psychiatric comorbidity, we are all at some genetic risk of being drug abusers. For this reason, we should focus on the environmental psychosocial factors that prevent the expression of underlying biological processes involved in drug abuse. Psychopharma-cology research is useful to provide indications of the types of environmental factors that can decrease drug-seeking behavior. These factors include punishment, response cost, and the availability of alternative sources of reinforcement. Considering the powerful counteracting influences of these and other environmental factors, it is postulated that is possible mitigate against the biological reality of the liability to self-administer drugs of abuse.