Does benadryl (diphenhydramine) cause vivid dreams?

Paradoxical effect: People often feel groggy and less rested in the morning after taking benadryl (diphenhydramine). Sleep is composed of repetitive cycles of non-rem and rem sleep. Dreams during rem sleep tend to be vivid, visual and story-like. It is thought that Benadryl (diphenhydramine) affects our rem sleep, possibly by decreasing it. Why decreased rem sleep causes vivid dreaming is a mystery, but it can. It's also common with antidepressants.

Nightmares Rarely: Benadryl (diphenhydramine) is a very effective medication for allergies and sleep in children. Of course, there are rare side effects that occur including nightmares. Stop the medication and find an alternative from your doctor if these dreams continue to occur. Vivid dreams are another issue and rest with the person experiencing them (probably form benadryl). Some people find them satisfactory.