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Clifford Qualls

3 papers in the library · 134 citations · publishing 1996-2026

Papers

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5-HT1A receptor blockade potentiates the subjective effects of DMT.

Journal of psychopharmacology (Oxford, England) May 2, 2026 Zarmeen Zahid, Rick J. Strassman, Clifford Qualls et al.

Serotonergic psychedelics are being investigated in the treatment of various disorders and in the improvement of well-being. Evidence suggests that their subjective effects may play a role in long-term behavioral outcomes. The subjective effects are mediated by 5-HT2A receptor agonism, but the 5-HT1A receptor may also play a role in the subjective effects. This study elucidates the effects of...

The Hallucinogen Rating Scale: Updated Factor Structure in a Large, Multistudy Sample.

Biological Psychiatry Global Open Science March 1, 2025 Abigail E. Calder, Clifford Qualls, Gregor Hasler et al. 5 citations

The Hallucinogen Rating Scale (HRS) has been widely used to measure the subjective effects of psychedelics and other psychoactive substances. Its advantages include a basis in phenomenological interviews and clinical studies, straightforward items, and broad coverage of psychedelic effects. Previous studies have attempted to resolve its factor structure but were limited by small samples of...

Differential tolerance to biological and subjective effects of four closely spaced doses of N,N-dimethyltryptamine in humans

Biological Psychiatry May 1, 1996 Rick J. Strassman, Clifford Qualls, Laura M. Berg 129 citations

Tolerance of the behavioral effects of the short-acting, endogenous hallucinogen, N,N-dimethyltryptamine (DMT) is seen inconsistently in animals, and has not been produced in humans. The nature and time course of responses to repetitive, closely spaced administrations of an hallucinogenic dose of DMT were characterized. Thirteen experienced hallucinogen users received intravenous 0.3 mg/kg DMT...