Prepulse inhibition (PPI) of startle is an operational measure of sensorimotor gating that is often impaired in patients with schizophrenia. Despite the large number of studies, there is considerable variation in PPI outcomes reported. We conducted a systematic review and meta-analysis investigating PPI impairment in patients with schizophrenia compared with healthy control subjects, and examined possible explanations for the variation in results between studies. Major databases were screened for observational studies comparing healthy subjects and patients with schizophrenia for the prepulse and pulse intervals of 60 and 120 ms as primary outcomes, ie, PPI-60 and PPI-120. Standardized mean difference (SMD) and 95% confidence intervals (CI) were extracted and pooled using random effects models. We then estimated the mean effect size of these measures with random effects meta-analyses and evaluated potential PPI heterogeneity moderators, using sensitivity analysis and meta-regressions. Sixty-seven primary studies were identified, with 3685 healthy and 4290 patients with schizophrenia. The schizophrenia group showed reduction in sensorimotor gating for both PPI-60 (SMD = −0.50, 95% CI = [−0.61, −0.39]) and PPI-120 (SMD = −0.44, 95% CI = [−0.54, −0.33]). The sensitivity and meta-regression analysis showed that sample size, gender proportion, imbalance for gender, source of control group, and study continent were sources of heterogeneity (P < .05) for both PPI-60 and PPI-120 outcomes. Our findings confirm a global sensorimotor gating deficit in schizophrenia patients, with overall moderate effect size for PPI-60 and PPI-120. Methodological consistency should decrease the high level of heterogeneity of PPI results between studies.

Resumo O Programa Criança Feliz (PCF) atinge 1,4 milhão de crianças brasileiras menores de três anos com visitas domiciliares visando o desenvolvimento neuropsicomotor. Com base em modelo conceitual, avaliou-se implementação e impacto do PCF em estudo randomizado, em 30 municípios. Ao todo 3.242 crianças foram alocadas para o grupo intervenção (GI) ou controle (GC), sendo 80,0% acompanhadas prospectivamente durante três anos. O desenvolvimento foi avaliado pelo Ages and Stages Questionnaire (ASQ3). Análises por intenção de tratar mostraram escores médios de 203,3 no GI e 201,3 no GC. Análises adicionais com variáveis instrumentais e emparelhamento por escores de propensão tampouco mostraram efeito, uma vez que o número de contatos recebidos não esteve associado aos escores ASQ3. Tampouco foi observado impacto sobre estimulação, interações responsivas ou atributos psicológicos das crianças. As visitas foram interrompidas durante 12 meses devido à COVID-19, sendo substituídas por contatos virtuais. O estudo de implementação revelou baixa cobertura no GI, contaminação do GC, deficiências na gestão e baixa qualidade das visitas em muitos municípios. O estudo não demonstrou impacto do PCF implementado sob condições de rotina e fornece elementos para seu aprimoramento.

Schizophrenic patients show deficits on stimulus salience tasks such as latent inhibition and blocking, which measure the ability to disregard irrelevant stimuli. Amphetamine-treated animals show similar deficits in analogous tasks, thereby providing a model of the stimulus-selection deficits observed in schizophrenia. In two experiments, the effect of the indirect dopamine (DA) agonist D-amphetamine sulphate (1.0 mg/kg, i.p.) on Kamin blocking and overshadowing were examined and compared, in the rat, using the conditioned lick suppression procedure. The aim was to provide some insight into the behavioural and pharmacological mechanisms underlying amphetamine effects in both paradigms. In experiment 1, it was shown that amphetamine selectively disrupted Kamin blocking, when given either at stage 2 alone, or at both stages of the task. In experiment 2, amphetamine treatment significantly abolished Kamin blocking and overshadowing, when administered prior to compound conditioning in both tasks. These data suggest that dopamine may play a critical role in mediating performance in tasks measuring stimulus salience processes. The results are discussed in the framework of the role of DA in stimulus-selection performance.