Drug
Addictions
Most
drugs that are used or abused to produce
euphoria in the brain's "pleasure center" called
accumbens, using the neurotransmitter dopamine.
Almost every drug of abuse either stimulates
dopamine release or enhances its activity.
Sustained use of a drug results in less
stimulation of the accumbens until eventually it
produces no euphoria at all.
Discontinuation
of the drug then produces a withdrawal effect
characterized by dysphoria (bad feeling) as the
accumbens activity reduces to below normal
levels.
Withdrawal
symptoms can vary significantly from person to
person, but the usual effects are less activity
in the accumbens followed by anxiety,
depression, and cravings, harm or even to
suicide.
