Prepulse inhibition (PPI) had little use for discriminating between diagnostic groups among patients who used cocaine with schizophrenia or antisocial personality disorder (APD). These findings were published in Brain Sciences.

Men (N=74) receiving treatment for a cocaine-related disorder were recruited at the Provincial Consortium Hospital in Spain. Participants were assessed for psychiatric conditions and for PPI by means of an intense pulse startle sensory stimulus (85 or 105 dB).

Participants were aged mean 41.84±8.27 years, 59.5% were single, 55.1% had no children, 31.1% were on permanent disability, half of the study participants (51.1%) used an average 70.74±59.71 mg/day of antipsychotics, 21 had schizophrenia, and 16 APD. On the basis of psychiatric condition, patients differed significantly by marital status (c2, 37.672; P <.001), educational attainment (c2, 48.038; P <.001), employment status (c2, 81.262; P <.001), and living arrangement (c2, 42.298; P =.001).

Patients with APD reported having more addictions (P =.009), were more likely to smoke or inject cocaine (P =.022), to be addicted to heroin (P <.001), or sedatives (P =.002) than other patients. Individuals without schizophrenia or APD started using cocaine later in life (P =.003) and became addicted later (P =.003).


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PPI at 30 ms was negatively correlated with quetiapine dose (r, -0.599; P =.04). Quetiapine users differed significantly from controls (mean, -33.48±34.63 vs 0.8±34.63; t, -2.274; P =.031).

At 30 ms, the APD group differed significantly from cocaine-related disorder alone (mean, -7.54% vs 17.49%; P <.05) but not from the schizophrenia (mean, -3.48%) or control (mean, 0.80%) cohorts. At 60 and 120 ms, no PPI group differences were observed.

Patient groups differed significantly for Levenson Self-Report Psychopathy Scale primary psychopathy (F[3,68], 9.842; P =.000) and secondary psychopathy (F[3,68], 15.474; P =.000), Hare Psychopathy Checklist Revised affective disorder (F[3,63], 103.019; P =.000), social deviation factor (F[3,63], 230.574; P =.000), and total score (F[3,63], 230.495; P =.000), and Sensitivity to Punishment and Reward Questionnaire punishment (F[3,68], 6.369; P =.001) and reward (F[3,68], 15.509; P =.000) subsections.

It remains unclear whether these observations may be generalizable to women.

Although PPI is an endophenotype, it had little use for differentiating between patients with schizophrenia or APD and a cocaine-related disorder.

Reference

Gil-Miravet I, Fuertes-Saiz A, Benito A, Almodóvar I, Ochoa E, Haro G. Prepulse inhibition in cocaine addiction and dual pathologies. Brain Sci. 2021;11(2):269. doi:10.3390/brainsci11020269