It has been estimated that more than 80% of alcoholics are also nicotine dependent and
that, vice versa, the rate of alcoholism is substantially increased by a factor of 4–10 in the …

Highlights•Alterations in endogenous opioid system components occur in development of
addiction.•Human studies and animal models show opioid genes contribute to addiction …

The opioid system consists of three receptors, mu, delta, and kappa, which are activated by
endogenous opioid peptides processed from three protein precursors, proopiomelanocortin …

The endogenous opioid system is expressed throughout the brain reinforcement circuitry,
and plays a major role in reward processing, mood control and the development of …

Drug addiction is a chronic brain disorder leading to complex adaptive changes within the
brain reward circuits that involve several neurotransmitters. One of the neurochemical …

The endogenous opioid system (EOS) plays a critical role in addictive processes. Molecular
dysregulations in this system may be specific for different stages of addiction cycle and …

The discovery of endogenous opioids has markedly influenced the research on the biology
of drug dependence. Evidence has been presented that these brain substances are self …

The roots of the Laboratory of the Biology of the Addictive Diseases are in the development
of methadone maintenance for the treatment of opiate addiction. Methadone maintenance …

A number of dramatic breakthroughs in the neurobiology of addiction have occurred in the
past 40 years. Two domains will be highlighted: the neurocircuitry of addiction and the …

A large range of neuroadaptations develop in response to chronic opioid exposure and
these are thought to be more or less critical for expression of the major features of opioid …