Sensorimotor gating is impaired in male patients with bipolar disorder (BP) and depression, according to results published in Psychiatry. The results also indicate a positive correlation between startle measurements and certain medications used to treat BP, and these associations warrant further studies.
The study included non-manic participants with BP (n=106; 26 BP I, 80 BP II, 63 with depression, 43 euthymic) and age-, gender-, and ethnicity-matched healthy controls (n=232). The researchers assessed depression severity using the Hamilton Depression Rating Scale-21. They measured the electromyographic activity of the orbicularis oculi muscle with a computerized startle reflex test unit.
After analysis, male participants with depression showed significantly lower pre-pulse inhibition at a pre-pulse of 86 dB and 120 ms lead interval compared with male controls and euthymic male participants.
Unlike male participants, female participants with depression or euthymic state did not show lower pre-pulse inhibition compared with female controls. However, female participants with active psychosis had significantly lower pre-pulse inhibition compared with female participants without psychosis.
The results also indicated a relationship between pre-pulse inhibition and medication. Female participants taking typical antipsychotics showed significantly lower pre-pulse inhibition compared with female participants not taking those medications.
Pre-pulse inhibition was positively correlated with lamotrigine dosage in male participants and lithium dosage in female participants.
Taken together these findings suggest that sensorimotor gating is altered in male patients with bipolar disorder and depression. These findings did not apply to female patients with bipolar disorder, except female patients with comorbid current psychosis.
Matsuo K, Ota M, Hidese S, et al. Sensorimotor gating in depressed and euthymic patients with bipolar disorder: analysis on prepulse inhibition of acoustic startle response stratified by gender and state [published online April 18, 2018]. Psychiatry. 2018;9(123). doi:10.3389/fpsyt.2018.00123