Behavioral conditioning of immunosuppression is possible in humans

FASEB J. 2002 Dec;16(14):1869-73. doi: 10.1096/fj.02-0389com.


Behavioral conditioned immunosuppression has been described in rodents as the most impressive demonstration of brain-to-immune system interaction. To analyze whether behavioral conditioned immunosuppression is possible in humans, healthy subjects in this double-blind, placebo-controlled study were conditioned in four sessions over 3 consecutive days, receiving the immunosuppressive drug cyclosporin A as an unconditioned stimulus paired with a distinctively flavored drink (conditioned stimulus) each 12 h. In the next week, re-exposure to the conditioned stimulus (drink), but now paired with placebo capsules, induced a suppression of immune functions as analyzed by the IL-2 and IFN-gamma mRNA expression, intracellular production, and in vitro release of IL-2 and IFN-gamma, as well as lymphocyte proliferation. These data demonstrate for the first time that immunosuppression can be behaviorally conditioned in humans.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Behavior
  • Cells, Cultured
  • Conditioning, Classical*
  • Cyclosporine / pharmacology
  • Double-Blind Method
  • Humans
  • Immune Tolerance
  • Immunosuppression Therapy*
  • Immunosuppressive Agents / pharmacology
  • Interferon-gamma / biosynthesis
  • Interferon-gamma / genetics
  • Interleukin-2 / biosynthesis
  • Interleukin-2 / genetics
  • Lymphocyte Activation
  • Male
  • RNA, Messenger / biosynthesis
  • T-Lymphocytes / immunology


  • Immunosuppressive Agents
  • Interleukin-2
  • RNA, Messenger
  • Interferon-gamma
  • Cyclosporine