IFNA1 and major depressive disorder: This CIRS mechanisms may also explain the contradictory findings on the TRYCAT pathway in acute depressive states (for example, IFNα-induced depression where there is a strong association between TRYCAT aberrations and the onset of depression) and major depression (DSM-IV-TR criteria), where these associations are much weaker probably because lowered tryptophan and increased TRYCATs have attenuated the initial immune-inflammatory response.