In the present study, we investigate the effect and possible mechanism of IL‐17A on depressive‐like behaviors of psoriasiform dermatitis mice and evaluate the alleviation effect of IL‐17A neutralization on its neuronal inflammatory reaction and depressive‐like behaviors to demonstrate further the pathogenic effect of IL‐17A on the psychological comorbidity of depression in psoriasis patients. This evidence concerns the gene IL17A and psoriasis.