The Arvid Carlsson Foundation has decided to award its major prize for outstanding research in the spirit of Arvid Carlsson to Lars Olson at the Karolinska Institute for the year 2023. Olson is honored for his crucial studies on monoaminergic neurotransmission and mechanisms of plasticity in the central nervous system. The prize consists of a research grant of SEK 700,000. At the same time, Sophie Erhardt and Johan Lundberg at the Karolinska Institute were each rewarded with grants of SEK 400,000. Erhardt is recognized for her intriguing studies on mechanisms relevant to the pathophysiology and treatment of schizophrenia, while Lundberg is acknowledged for his fascinating studies on mechanisms relevant to the pathophysiology and treatment of depression. The award ceremony took place in Gothenburg.