Final answer:
Carl likely experienced an increase in the neurotransmitter dopamine after overdosing on amphetamines, which is known to induce psychosis at high doses.
Step-by-step explanation:
When Carl overdosed on amphetamines and began to experience drug-induced psychosis, including hallucinations and delusions, it is likely that Carl experienced an increase in the neurotransmitter dopamine. Amphetamines increase the release of dopamine and block its reuptake, which can lead to elevated levels of this neurotransmitter in the brain. Studies have shown that excessive dopamine activity, especially in the limbic and mesocortical brain pathways, is associated with psychotic symptoms.
Amphetamines, such as methamphetamine, can induce psychosis at high doses, which includes not only dopamine but also affects serotonin and norepinephrine levels, contributing to the drug's powerful central nervous system stimulant effects. Treatment for psychosis often involves antipsychotic medications that block dopamine receptors, as this neurotransmitter's overactivity is recognized to underlie many of the symptoms.