5.03 Stimulants (Types, Intoxication, and Withdrawal)
Psychiatry review for the USMLE Step 1 Exam.
- Stimulants increase CNS activity and activate the sympathetic nervous system.
- They can block reuptake of neurotransmitters or stimulate their release.
- Intoxication symptoms include agitation, dilated pupils, sweating, euphoria, hallucinations, and increased norepinephrine, epinephrine, dopamine, and serotonin levels.
- Prescribed stimulants: amphetamine, dextroamphetamine, and methylphenidate (used for ADHD).
- Recreational stimulants: methamphetamine, cocaine, MDMA, nicotine, and caffeine.
- Cocaine blocks reuptake of norepinephrine, epinephrine, and dopamine, and can cause hallucinations, paranoia, chest pain, and potentially cardiac death.
- Methamphetamine can cause tactile hallucinations where patients feel like bugs are crawling on their skin.
- MDMA can induce feelings of connectedness, heightened emotions, and hallucinations.
- Withdrawal from stimulants, particularly cocaine and methamphetamine, is characterized by depression, headache, malaise, fatigue, hypersomnolence, anhedonia, constricted pupils, vivid dreams, and flu-like symptoms.
- Withdrawal symptoms are opposite to the effects experienced during intoxication.