Several neurologic conditions, including narcolepsy, Parkinson's disease, Lewy body dementia, migraine, posttraumatic stress disorder (PTSD), and obstructive sleep apnea increase the risk of nightmares. The reasons vary from disorder to disorder. In narcolepsy, for example, the lack of the neurotransmitter orexin weakens the boundary between sleep and wakefulness. In Parkinson's disease and Lewy body dementia, the cause is a disturbance in dopamine. In PTSD, nightmares are the result of a heightened fight-or-flight response and overactivation of the nervous system.
Certain medications may trigger nightmares. Beta-blockers like metoprolol (Lopressor) can induce bad dreams because they inhibit the release of melatonin, a hormone the body produces to help regulate sleep. However, melatonin supplements taken to induce sleep also could cause nightmares. Selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (Prozac) and paroxetine (Paxil), which increase levels of serotonin in the brain, could affect sleep and dreams. Non-SSRI antidepressants, including venlafaxine (Effexor), bupropion hydrochloride (Wellbutrin), and duloxetine (Cymbalta), are potential triggers.
Some of the newer weight loss drugs, such as semaglutide (Ozempic, Wegovy), and certain antibiotics, including ciprofloxacin (Cipro) and erythromycin, have been reported to cause nightmares in some people. Stimulants such as methylphenidate (Ritalin) or amphetamine/dextroamphetamine (Adderall) can cause vivid dreams, possibly because they increase levels of dopamine, which may relieve drowsiness and add energy.
Other drugs that affect dopamine levels and possibly cause nightmares are those used to treat Parkinson's disease—including carbidopa/levodopa (Sinemet), amantadine hydrochloride (Symmetrel), and selegiline hydrochloride (Eldepryl)—as well as antipsychotic medications such as clozapine (Clozaril), olanzapine (Zyprexa), and risperidone (Risperdal).
If medications are the cause of disturbing dreams, health care providers can change the dose, try a different drug, or add a medication at night to ease sleep. To prevent injury in people who have REM sleep behavior disorder—a sleep abnormality where they act out their dreams by shouting, punching, or kicking—place pillows around the sleeper, put a rug on the floor, and remove any furniture near the bed.
A common treatment for nightmares is the blood pressure medication prazosin (Minipress), although it's not effective for everybody. Nondrug therapies include imagery rehearsal therapy, which trains people to have more positive versions of dreams. Both cognitive behavioral therapy, which teaches healthy sleep behaviors and addresses fears associated with nightmares, and self-hypnosis, which can put the brain into a state of deep relaxation, can help reduce nightmares in some cases.
Tell your physician if you have nightmares so the doctor can consider possible causes and treatment. Reducing or eliminating bad dreams should lessen daytime drowsiness and improve functioning.
Dr. Attarian is professor of neurology at Northwestern University Feinberg School of Medicine in Chicago.
