Understanding Delirium: Why It Matters in Criminal and Civil Cases

Delirium is a common yet frequently misunderstood medical condition that can have significant implications in both criminal and civil litigation. Delirium is characterized by a sudden change in mental status that impairs a person’s ability to focus, maintain attention, process information, and think clearly. Unlike chronic cognitive disorders such as dementia, delirium develops rapidly—often within hours to days—and can fluctuate in severity throughout the day (G. Bryan Young, 2026; Joseph Francis, 2024).

From a legal perspective, individuals experiencing delirium may appear confused, disoriented, agitated, intoxicated, uncooperative, or unable to accurately recall events. These symptoms can affect a person’s decision-making abilities, memory, perception of reality, and ability to communicate effectively. As a result, delirium may become a relevant consideration when evaluating competency, intent, reliability of statements, informed consent, witness credibility, or an individual’s actions during a specific event.

One of the challenges in evaluating delirium is that it is often multifactorial, meaning multiple factors may contribute to its development simultaneously. Medications are among the most common contributors. Research demonstrates that polypharmacy—the use of multiple medications—increases the risk of delirium significantly. Medications frequently associated with delirium include opioids, antipsychotics such as Haldol, antihistamines such as Benadryl, and benzodiazepines such as Ativan (G. Bryan Young, 2026). Delirium may also occur during alcohol or benzodiazepine withdrawal.

Drug toxicity is another important consideration. Certain medications, including Digoxin and Lithium, have been associated with delirium when blood levels become elevated or when the body’s ability to process the medication is impaired. Research suggests medication-related toxicity may contribute to approximately 30% of delirium cases (Joseph Francis, 2024).

Infections are also a leading cause of delirium, particularly among older adults and medically vulnerable individuals. Studies have shown that delirium may occur in up to half of patients with certain infections. Urinary tract infections and respiratory infections are among the most common infectious causes, although more serious conditions such as bloodstream infections, endocarditis, and central nervous system infections can also result in delirium (G. Bryan Young, 2026).

Additional medical conditions frequently associated with delirium include dehydration, electrolyte abnormalities, low or high blood sugar levels, liver dysfunction, oxygen deprivation, and elevated carbon dioxide levels. Environmental factors may also play a role. Sleep deprivation, sensory impairment, vision loss, hearing deficits, and unfamiliar surroundings can contribute to the development or worsening of delirium (G. Bryan Young, 2026).

Importantly, delirium is not a disease itself but rather a symptom of an underlying medical issue. Treatment focuses on identifying and correcting the underlying cause, whether that involves treating an infection, adjusting medications, correcting metabolic abnormalities, restoring hydration, or addressing environmental stressors. Once the underlying condition is treated, the delirium often improves or resolves (Joseph Francis, 2024).

Why Expert Review Matters

For attorneys, the presence of delirium can significantly impact the interpretation of behavior, statements, and medical evidence. A person experiencing delirium may appear intoxicated despite having no alcohol or illicit substances in their system. They may provide inconsistent accounts, exhibit unusual behavior, have impaired judgment, or struggle to form or retain memories. Without a thorough medical review, these symptoms may be misinterpreted as intentional misconduct, substance abuse, psychiatric illness, or noncompliance.