This has references newer than 2008: https://www.alzdiscovery.org/uploads/cognitive_vitality_media/Diphenhydramine-Cognitive-Vitality-For-Researchers.pdf https:

This has references newer than 2008: https://www.alzdiscovery.org/uploads/cognitive_vitality_media/Diphenhydramine-Cognitive-Vitality-For-Researchers.pdf https://www.alzdiscovery.org/uploads/cognitive_vitality_medi... At the top, it talks about "long term use", so it may be okay under acute circumstances.