Acetaldehyde as the first hit of addictive behaviour

Unhealthy alcohol use is common in the Western society, which puts risk of health consequences, causing multiple behavioural injuries. Increasing evidence focuses on acetaldehyde, the first metabolite of ethanol, as the mediator of the several behavioural actions of alcohol, including its rewarding and motivational effects. In particular, acetaldehyde induces dopamine release in the nucleus accumbens modulating primary alcohol rewarding effect, drug seeking, and relapse behaviour. Recent behavioural studies point at acetaldehyde as a drug of abuse since its oral self-administration is induced and maintained in an operant/conflict paradigm. These findings provide further evidence on the role played by the acetaldehyde as a mediator of the effects of alcohol and focus attention on this molecule to arrange a more effective strategy, aimed at the prevention and treatment of alcohol abuse. Thus, the aim of this review is to summarize latest results on the role of acetaldehyde as the mediator of ethanol-central effects focusing on its capacity to induce an addictive behaviour.