The chemical dependence is quite a factor in the psychological process you refer to. It nudges and reinforces this psychological behaviour. You can broaden the definition to include addiction without chemical dependence, but it does not mean you can omit the chemical dependence factor from the equation.
This chemical dependence is often the number one reason people cannot physically stop their psychological process. Potential effects from quitting include simply dying, or with less strong chemical dependence, feeling anxiety or generally ill.
This chemical dependence is often the number one reason people cannot physically stop their psychological process. Potential effects from quitting include simply dying, or with less strong chemical dependence, feeling anxiety or generally ill.