Schizophrenia patients exhibit inhibitory gating deficit in the prepulse inhibition (PPI) of acoustic startle response (ASR) and in the P50 auditory evoked potential suppression.

Deviant sexual behavior (DSB) often complicates early clinical identifying of schizophrenic disorder. In this study we assessed the inhibitory gating measures in schizophrenic patients with DSB.

Participants (males) were 12 schizophrenic patients with DSB, 14 schizophrenic controls (SC) and 26 healthy controls (HC). DSB was mainly related to disorders of sexual preference. P50 suppression was measured during two runs of 50 click pairs with 500-msec interval. PPI was measured using a series of prepulse-pulse pairs with lead intervals (LI) 60 ms and 120 ms.

SC group showed reduced PPI compared to HC. PPI deficit was the most prominent at 60 ms LI, and was right-sided only at 120-ms LI. DSB group demonstrated left-sided reduced PPI at 60 ms LI and left eye ASR latency reduction at 120 ms LI. SC exhibited the highest (0,87), and HC the lowest (0,39) S2/S1 ratio in P50 paradigm; the intermediate value (0,67) was found in DSB patients. In both patient groups S2/S1 ratio significantly (p < 0,001) differed from that in HC. No significant differences were revealed in P50 and PPI measures between patient groups that may be related to high variability in SC group.

Left-side PPI deficit in DSB patients is possibly related to right hemisphere disturbances that are inherent to patients with sexual disorders. P50 and PPI measures may be useful to identify schizophrenic disorder in patients with DSB.