Britannica Sources used in this answer

Why can high doses of stimulant drugs lead to paranoia?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

drug use The use of psychoactive drugs, such as pain medications or illegal substances, often results in emotional, physical, and social harm.

High doses of stimulant drugs, particularly amphetamines, can induce a state of toxic psychosis characterized by paranoid delusions, hallucinations, and ideas of reference. This condition, often referred to as amphetamine psychosis, can occur even with a single dose in individuals without prior drug tolerance.1

The mechanism behind this effect is linked to the drug's impact on the central nervous system. Stimulants like dextroamphetamine increase the levels of neurotransmitters such as dopamine and norepinephrine in the brain by inhibiting their reuptake and directly stimulating their release. Because dopamine plays a critical role in motivation, attention, and the regulation of neural "signal-to-noise" ratios, abnormal signaling caused by excessive stimulant use can disrupt these processes, contributing to the development of symptoms that may be clinically indistinguishable from paranoid schizophrenia.213

It is important to recognize that the misuse of these substances poses severe risks to mental and physical health, including the potential for permanent organic brain damage.12