Contrastingly, a human study showed that the Cnr1 level and DNA methylation at the Cnr1 promoter did not change the peripheral blood mononuclear cells of patients with bipolar disorder (type I and II) and major depressive disorder; however, it should be noted that these subjects received long-term pharmacological treatment that may alter that gene expression [45]. The gene discussed is CNR1; the disease is bipolar disorder.