Evidence that 5‐HT2A receptor signalling efficacy and not biased agonism differentiates serotonergic psychedelic from non‐psychedelic drugs. - Ippolito, Aurelija; Vasudevan, Sridhar; Hurley, Shaun; Gilmour, Gary; Westhorpe, Frederick; Churchill, Grant; Sharp, Trevor (British Journal of Pharmacology, 2026)