Prevalence and Clinical Correlates of Autistic Features in Patients with Initial-Treatment and Drug-Naive Schizophrenia.

Objective: A distinct subtype of schizophrenia (SCZ) is the one accompanied with autistic features (AF). This study aimed to determine the prevalence of AF in initial-treatment and drug-naive (ITDN) patients with SCZ and investigate its influencing factors.

Methods: The study recruited 710 ITDN patients with SCZ. Their sociodemographic data and general clinical information were collected, and a clinical psychological assessment was performed to quantify their psychopathology and disease severity. The severity of AF was calculated based on psychopathology scores.

Results: Overall, 19.01% (135/710) patients with SCZ showed AF. Patients with AF exhibited higher levels of thyroid-stimulating hormone (TSH) (t = -4.54, P < .001) and lower levels of free triiodothyronine (FT₃) and free tetraiodothyronine (FT₄) (t = 2.38, P = .018; t = 3.19, P = .002) than those with AF. Binary logistic regression analysis revealed waist circumference (B = 0.03, P = .022, odds ratio (OR) = 1.03) and TSH level (B = 0.54, P < .001, OR = 1.71) as risk factors for AF, and deemed low-density lipoprotein cholesterol (B = -0.43, P = .025, OR = 0.65), fasting blood glucose (B = -0.72, P = .013, OR = 0.49), FT₃ (B = -0.32, P = .034, OR = 0.73), and FT₄ (B = -0.08, P = .025, OR = 0.93) levels as protective factors. Multiple linear regression analysis identified FT₃ level (B = -0.85, t = -2.22, P = .028, 95%, Confidence Intervals (CI): -1.61- -0.09) as a protective factor influencing AF severity.

Conclusion: This study reports the prevalence of AF in the target SCZ population and identifies factors associated with its development and severity. The discernment of these distinctive clinical features may facilitate formulation of tailored prevention strategies and interventions for this precise subset of SCZ patients.