Confusion from Diphenhydramine

Confusion is defined as an impairment of abstract thinking demonstrated by an inability to think with one's customary clarity and coherence. Within the context of substance use, it is commonly experienced as a persistent inability to grasp or comprehend concepts, situations, conversations, and environmental cues that would otherwise be perfectly understandable during sobriety. The person may find themselves unable to follow a simple train of thought, losing track of what they were doing mid-action, or struggling to understand straightforward questions.

The subjective experience of confusion can range from a mild mental fog to a profoundly disorienting state in which even basic aspects of one's situation become incomprehensible. At lower intensities, it may manifest as occasionally losing one's place in a conversation or momentarily forgetting what task was being performed. At higher intensities, the person may be unable to determine where they are, what time it is, why they are in a particular place, or what is happening around them. This can be accompanied by a frustrating awareness that one should be able to understand these things but simply cannot.

The intensity of this effect seems to be increased by unfamiliarity with either the setting or the substance being used. Novel environments, unexpected situations, and interactions with strangers tend to amplify confusion considerably. Conversely, familiar and comfortable settings with trusted companions can partially mitigate the effect. This makes set and setting particularly important considerations for substances known to produce significant confusion.

Confusion is often accompanied by and compounded by other coinciding effects such as delirium, delusions, thought disorganization, and short-term memory suppression. When these effects co-occur, the person's lack of comprehension can become quite severe, as they may not only fail to understand their current situation but also be unable to remember what happened moments ago or form accurate interpretations of sensory input. This combination is most commonly associated with deliriant compounds but can occur with any sufficiently high dose of a hallucinogen.

This effect is most commonly induced under the influence of heavy dosages of hallucinogenic compounds such as psychedelics, dissociatives, synthetic cannabinoids, and deliriants. Anticholinergic deliriants like diphenhydramine and datura are particularly notorious for producing states of extreme confusion. However, the effect can also occur with high doses of depressants including alcohol, benzodiazepines, and opioids. Even substances not typically associated with confusion, such as cannabis, can produce it in sensitive individuals or at unusually high doses.

While confusion is typically self-limiting and resolves as the substance is metabolized, it can contribute to dangerous situations by impairing the person's ability to recognize and respond to hazards, seek help when needed, or make sound decisions. The confused individual may wander into unsafe environments, fail to recognize signs of medical distress, or be unable to communicate their needs to others. For these reasons, having a sober companion present is particularly important when using substances known to produce significant confusion.