Neurobiological Basis of Drug Abuse

Alterations and neuroadaptations of intracellular messenger pathways, transcription factors, and immediate early genes within the brains’ reward and anti-reward circuits are considered to be the predominant factor for the development of drug abuse and addiction. Moreover, environmental and genetic factors as well as epigenetic adaptations are involved. Besides neuronal alterations, the involvement of glial cells (microglia, astrocytes, oligodendrocytes) and disturbances of the blood–brain barrier play an important contributory role. Although animal models have shown profound insight in the consequences of drug abuse, extrapolating the findings to the human CNS must be considered with caution.