Dopamine manipulations modulate paranoid social inferences in healthy people
bioRxiv (Cold Spring Harbor Laboratory) December 19, 2019 J.M. Barnby, Vaughan Bell, Quinton Deeley et al. 4 citations preprint
Dopamine transmission influences social attributions related to paranoia, but not the salience of paranormal or other beliefs. In a double-blind, placebo-controlled experiment, 27 healthy men received either L-DOPA (150 mg), haloperidol (3 mg), or placebo across three sessions. Haloperidol reduced attributions of harmful intent in a Dictator Game, while L-DOPA reduced such attributions only in fair conditions. Haloperidol unexpectedly increased attributions of self-interest for opponents' decisions. No changes occurred in belief salience for politics, religion, science, morality, or the paranormal. These results suggest dopamine selectively affects social inferences linked to paranoia, independent of mood or skepticism.