Smoking prevalence in patients who are diagnosed with schizophrenia (SCZ) is higher than in the general population. Chronic tobacco use in SCZ patients may reduce the side effects of antipsychotic drugs, thus serving as a self-medication for such side effects. Understanding the ways in which chronic tobacco use influences visual sensitivity has clinical implications, which may serve as a tool for non-invasively diagnosing early-stage visual processing deficits. The present study evaluated the effects of chronic tobacco use on visual sensitivity in SCZ patients. Our purpose was to provide new directions for future research, mainly psychophysical and electrophysiological studies. In the present study, 40 smoker controls (SC), 20 SCZ tobacco users, and 20 SCZ tobacco nonusers were recruited from the Psychosocial Care Center. Visual sensitivity was compared between both SCZ groups and the SC group. Patients with SCZ who were chronic tobacco users presented lower visual sensitivity for chromatic (p < 0.001) and achromatic (p < 0.001) stimuli compared with the other groups. Our findings highlight the need to evaluate possible addictive behavior in patients with SCZ, which may contribute to public policies that seek to improve the quality of life of SCZ patients and their families.

This study analyzed the fluctuation of the achromatic visual contrast sensitivity (CS) of adult males (M = 23.42 ± 2.6 years) during a daily period. Twenty-eight volunteers were divided into three groups according to circadian typology (CT): moderate morning (MM; n = 8); intermediate (I; n = 10) and moderate evening (ME; n = 10). The Pittsburgh Sleep Quality Index was used to evaluate sleep quality, and the Horne and Ostberg Morningness-Eveningness Questionnaire was used to measure CT. To measure CS, we used Metropsis software version 11.0 with vertical sinusoidal grids of 0.2, 0.6, 1, 3.1, 6.1, 8.8, 13.2 and 15.6 cycles per degree of visual angle (cpd). The stimuli were presented on a cathode ray tube (CRT) color video monitor with a 19-inch flat screen, a 1024 × 786 pixel resolution, a 100 Hz refresh rate and a photopic luminance of 39.6 cd/m. It was inferred that there is a tendency for visual contrast to vary according to daily rhythmicity and CT, mainly for the median spatial frequencies (1.0 cpd, χ = 9.93, p < 0.05 and 3.1 cpd, χ = 10.33, p < 0.05) and high spatial frequencies (13.2 cpd, χ = 11.54, p < 0.05) of ME participants. ME participants had minimal visual contrast sensitivity during the morning shift and a progressive increase from afternoon to night.

Resumo O objetivo desta pesquisa foi adaptar a Structured Interview for Assessing Perceptual Anomalies (SIAPA) para o Brasil para ser utilizada como instrumento de autorrelato. Utilizou-se uma amostra não probabilística de 854 universitários, a maioria do sexo masculino (51,4 %) e com idades entre 16 e 65 anos (M = 23,7; DP = 6,8). Após a tradução e validação semântica da SIAPA, testaram-se os parâmetros de validade e precisão por meio de análises fatoriais, coeficientes alfa de Cronbach e análises via Teoria de Resposta ao Item (TRI). Os resultados confirmaram a adequação psicométrica da medida, apontando uma solução unidimensional com altas cargas no fator geral e alta consistência interna (α = 0,88; Ω = 0,88). Acredita-se que o objetivo proposto tenha sido satisfeito, de modo que, ao final da pesquisa, contou-se com uma medida válida e fidedigna que pode ser utilizada, tanto para rastreio quanto para pesquisa, para compreender e diagnosticar anomalias perceptuais.