Experts Explain Why Some Common Medicines Might Be Causing Nightmares

If you have been having strange or scary dreams lately, the reason might not be stress or a horror movie before bed. It could actually be your medicines. According to sleep experts, many common drugs, including antidepressants, statins, and even sleep aids, can cause vivid or frightening dreams.

Doctors say that these nightmares are not uncommon and are linked to how certain medicines affect the brain and sleep patterns. Dr. Clete Kushida, the medical director at Stanford Sleep Medicine, explains that many medications can change how the brain controls sleep, especially the phase called REM sleep — the stage when most dreams occur.

Medications like antidepressants, beta blockers (used for blood pressure), statins (used for cholesterol), and even pills for ADHD or Parkinson’s disease can sometimes trigger bad dreams. Even over-the-counter allergy medicines, sleep aids such as Ambien or Lunesta, and the new weight loss injections like Ozempic or Mounjaro have been linked to nightmares.

Dr. Kushida said, “There are many medicines that can cause nightmares or vivid dreams. Even melatonin or short-term sleeping pills can be linked to them, although we still do not completely understand why.”

Scientists believe the reason lies in how these medicines change brain chemistry. For example, antidepressants that raise serotonin levels, like SSRIs and SNRIs, can increase brain activity during REM sleep, making dreams feel more real or intense. On the other hand, medicines that affect dopamine — a chemical related to mood and movement — can directly influence dream patterns.

Some Alzheimer’s drugs, like Aricept, can even cause a condition called REM sleep behavior disorder. In this case, people physically act out their dreams while sleeping. Beta blockers, on the other hand, may reduce REM sleep but strangely still lead to more nightmares once that stage returns.

Doctors also warn that people should never stop taking their medicines suddenly, even if nightmares become frequent. Stopping a prescription without a doctor’s advice can cause serious health problems. Instead, they suggest talking to your doctor about adjusting the dose or changing the time you take the medicine. Sometimes, taking medicine earlier in the day can help reduce the effect on dreams.

Nightmares can do more than disturb sleep. After several nights of bad dreams, people may feel anxious, tired, or afraid to go to bed. Dr. Kushida said, “A long stretch of bad dreams can leave you uneasy or scared, and that can make it harder to sleep well.”

Experts also remind people that medicines are not the only cause of nightmares. Other conditions, such as sleep apnea, stress, or certain mental health issues, can also trigger disturbing dreams. The National Institutes of Health says that treating sleep-related disorders can improve sleep quality and reduce nightmares.

Doctors recommend keeping a sleep diary to track when nightmares occur and whether they are linked to new medications or changes in dosage. They also encourage regular exercise, reducing caffeine before bed, and keeping a calm bedtime routine to promote better sleep.

In most cases, these medication-related nightmares are not dangerous, but they can be unpleasant. Recognizing the cause and speaking openly with your doctor can make a big difference.

Dr. Kushida’s main advice is simple: if you start having strange or scary dreams after beginning a new medicine, don’t panic. Keep a note of what you’re experiencing and talk to your doctor. A small change in your medication plan could help you sleep peacefully again.