INDUCTION OF CYTOKINE SYNTHESIS AND FEVER SUPPRESSES REM-SLEEP AND IMPROVES MOOD IN PATIENTS WITH MAJOR DEPRESSION

Beneficial effects of inflammatory events on certain psychiatric disor ders, including depression, were reported sporadically by ancient Gree k physicians, but have been described also in our times by a few psych iatrists during the past decades. During febrile inflammatory events, mediators of the immune system such as interleukin-1 can be detected i n the brain and may act on their respective receptors which have also been demonstrated in the brain, Since cytokines such as interleukin-1 have been shown in animal studies to exert sedative behavioral effects , to be somnogenic, and to induce slow-wave sleep (SWS), we performed a pilot study to evaluate scientifically the anecdotically reported be neficial effects of inflammatory states on depressive disorders. Mood and sleep parameters were monitored in seven drug-free, severely depre ssed patients before, during, and after the administration of a single dose of endotoxin. All patients responded with a short pulse of incre ased synthesis of the cytokines tumor necrosis factor, interleukin-1, and interleukin-6 and elevated body temperature for several hours. Dur ing the night following endotoxin administration, rapid eye movement ( REM) sleep was significantly suppressed while changes in slow wave sle ep were not significant. During the next day, all patients were in a s ignificantly improved mood; however a rebound of REM sleep was observe d in the second night after endotoxin administration and mood worsened again during the next days, indicating an only transient beneficial e ffect of the treatment.