Bipolar disorder is one of the major causes of disability causing cognitive and functional disorders and increased mortality and death, especially due to suicide. The first episode of bipolar disorder is mostly depression. Depression episodes last significantly longer than manic or hypomanic episodes for most people with bipolar I or bipolar II disorder. The estimated heritability of bipolar disorder is between 70 and 90%. Genetics, especially the effect of small genes on potential underlying neurobiological pathways of bipolar disorders, have been obtained from genome-related studies. The present comparative study investigated the expression of BDNF and DRD4 genes in samples with bipolar disorder and healthy subjects. For this purpose, 25 subjects with bipolar disorder with a history of at least two hospitalizations and with an MMPI score above 70 were randomly selected. Among the patients hospitalized in Tabriz Razi Hospital and 20 healthy subjects were randomly selected, 5 cc of their peripheral blood was extracted using Dena Zist and Sina Cologne kits, RNA was extracted and then synthesized After quality measurement of cDNA using Oligo dT. After synchronizing, their expression of genes was measured using specific primers and real-time PCR. The results revealed that the MMPI index in bipolar patients is significantly higher than in healthy subjects. However, the relative expression of BDNF and DRD4 genes in bipolar patients decreased significantly (P-value<0.05). If it is proven in more samples, it can be used as a molecular marker in early and accessible screening of people prone to bipolar disorder.
