Distinctively lower DISC1 mRNA levels in patients with schizophrenia, especially in those with higher positive, negative, and depressive symptoms.

The issue of genetic influence on schizophrenia has received considerable attention. The DISC1 gene has been shown in several studies to play a role in the pathophysiology of schizophrenia. However, the relationship between DISC1 mRNA expression vs. schizophrenia and its clinical symptoms is uncertain. Fifty-six subjects (32 patients with schizophrenia and 24 healthy controls) were enrolled. Peripheral blood was obtained from all subjects to exam the DISC1 mRNA expression. Schizophrenia patients were evaluated with Hamilton Rating Scale for Depression (HAMD), Positive and Negative Syndrome Scale (PANSS), Brief Psychiatric Rating Scale (BPRS) and Scale for the Assessment of Negative Symptoms (SANS) scales. Healthy subjects were assessed with HAMD scale. Patients with schizophrenia had significantly lower levels of the DISC1 mRNA expression than the healthy control (P = 0.002). We also found that lower DISC1 mRNA levels in schizophrenia patients were associated with higher degree of depression in HAMD (P = 0.037), severer positive symptoms in PANSS (P = 0.032) and more negative symptoms in SANS (P = 0.038). The results showed that schizophrenia patients had lower levels of DISC1 mRNA than healthy individuals, and that the schizophrenia patients with lower DISC1 mRNA levels were more likely to manifest more marked symptoms, including positive, negative, and depressive symptoms. The findings suggest that lower DISC1 expression may be related with the pathogenesis and phenotypes of schizophrenia. Future studies are needed to replicate the results and to further establish its potential role in clinical application of early diagnosis and outcome follow-up.