Images

The model focusses on the common underlying risk factors that are shared between several different forms of addiction.

Many regions and circuits in the brain are involved in the control of motivation, which can be dysregulated by substance-use disorders and other addictions. There are four key independent and overlapping circuits implicated in addiction, as shown on image.

The endogenous opioid system of the brain consists of several neurotransmitters that bind in different ways to 3 different G-protein coupled receptors, called the delta (δ), mu (μ), and kappa (κ) receptors.

Substance use is driven by the pharmacological effects of a drug, which are experienced as reinforcing/rewarding

The interaction between neurocircuitry and behaviour of addiction, divided into binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation, each of which is associated with the activation of certain neurological pathways.

The image shows how alcohol may interact with the neurotransmitter systems of the brain’s reward pathway, by inhibiting GABA signalling in the ventral tegmental area which in turn disinhibits dopaminergic projections to the nucleus accumbens.