Final answer:
Nicotine is most likely to be overused by individuals with schizophrenia due to its effects on acetylcholine, and methadone is used to treat heroin addiction .
Step-by-step explanation:
Among the listed substances, nicotine (smoking) is most likely to be overused by individuals with schizophrenia. People with schizophrenia are known to have higher rates of smoking.
The general population, and nicotine affects the neurotransmitter acetylcholine, which may have a modulating effect on the symptoms of schizophrenia.
Possible withdrawal symptoms associated with physical dependence on a psychoactive drug, like nicotine, include anxiety, depression, and cravings.
For a person with heroin addiction, methadone is commonly used because it reduces cravings and withdrawal symptoms without the high associated with heroin.
The recreational use of psychoactive drugs often seeks to alter consciousness and may lead to the compulsive use of substances such as nicotine despite negative consequences.