Psychosis in a Military Veteran in the Context of Hallucinogen Use: A Case Report.

N, N-dimethyltryptamine (DMT) is a potent hallucinogenic compound with increasing recreational use despite limited safety data. While DMT use has been linked to psychosis, delusional parasitosis as a specific manifestation remains unreported. We present a novel case of a 60-year-old female veteran with chronic post-traumatic stress disorder (PTSD), a history of major depressive disorder, past marijuana use, and no history of prior psychiatric hospitalizations, who developed persistent delusions of parasitic infestation following prolonged recreational intravenous (IV) DMT. She was referred to acute inpatient psychiatry by the residential PTSD program in the same hospital system, where she expressed upon intake there the strong conviction that worms were coming out of her skin. Upon admission to inpatient psychiatry, the patient presented with severe anxiety about minor appearing skin excoriations. These were likely a result of and consequent precipitator of her delusion that a parasite-infected her eight months ago during a plumbing leak in her home. A review of her records revealed endorsement of these symptoms to multiple providers over the past eight months. She also reported using IV DMT at home 1-2 times per month for the past 18 months. As the timing of hallucinogen use and the development of psychotic symptoms were not fully consistent, there was a concern for a primary delusional disorder that was likely exacerbated by her substance use. Her delusions persisted despite initial haloperidol treatment initiated during hospitalization but improved after 15 days of hospitalization, following substance clearance and psychoeducation. This case suggests a novel potential link between prolonged DMT use and delusional parasitosis, as no published studies have specifically explored this association, highlighting the need for further research, particularly with repeated and IV administration.