Targeting IL-17A signaling in suicidality, promise or the long arm of coincidence? Evidence in psychiatric populations revisited

•Suicides which occurred in a biologics trial targeting the IL-17R are revisited.•High IL-17 levels are found in depression by the majority of reports.•Results from studies regarding IL-17 and psychosis are mixed.•Very few psychiatric studies investigated IL-17 signalling in suicidality.•Potential mechanisms how IL-17 influences neuro-inflammation are described.