[Plasma levels of nociceptin/orphanin FQ in patients with bipolar disorders and health adults].

OBJECTIVE

To investigate the plasma levels of nociceptin/orphanin FQ (OGQ) in patients with bipolar depression and bipolar mania and to analyze the relationship of plasma OFQ to bipolar disorders.

METHODS

Peripheral blood samples were collected from 21 patients with bipolar II depression (BD group), 26 patients with bipolar I mania (BM group), and 31 health adults (control group). The concentrations of plasma OFQ were measured by radioimmunoassay (RIA). The psychological status was examined by Hamilton Depression Scale (HAMD), Bech-Rafaelsen Mania Rating Scale (BRMS), and Montgomery and Asberg Depression Rating Scale (MADRS).

RESULTS

The plasma OFQ level of the BD group was (20+/-4) ng/L, significantly higher than that of the control group [(14+/-5) ng/L, t=5.28, P<0.01], and the OFQ level of the BM group was (11+/-3) ng/L, significantly lower than that of the control group (t=-2.47, P<0.05). There were not significant differences in the plasma OFQ between the males and females in all groups (all P>0.05). In the BD group the plasma OFQ level was significantly positively correlated with HAMD and MADRS scores (r=0.607, P<0.01; r=0.541, P<0.05). In the BM group the plasma OFQ level was significantly negatively correlated with the BRM score (r=-0.750, P<0.01).

CONCLUSION

The changes of plasma OFQ level may play a role in the pathogenesis of bipolar disorder and indicate the severity of disease. Plasma OFQ may be a new biological parameter of bipolar disorder.