Final answer:
Withdrawal from alcohol and barbiturates can result in seizures due to the unbalanced adaptations in the brain's reward circuitry after the removal of these substances.
Step-by-step explanation:
Withdrawal from alcohol and barbiturates can cause a variety of symptoms due to changes in the central nervous system. One of the serious potential effects of withdrawal from these substances is the occurrence of seizures. This happens because chronic exposure to alcohol and barbiturates leads to compensatory adaptations within the brain’s reward circuitry. When these substances are suddenly removed, the adaptations that resulted from prolonged use, such as an increase in glutamatergic activity, are no longer balanced by the inhibitory effects of alcohol or barbiturates, leading to a hyperactive state that can result in seizures. Due to the risk involved, medical supervision is highly recommended when withdrawing from these substances.