Callous–unemotional (CU) traits are characterised by reduced empathy, guilt, and emotional responsiveness, and are strongly linked to atypical socioemotional processing. Eye-tracking research provides a valuable window into these processes by capturing early developing patterns of attention to emotionally salient social cues, particularly facial expressions. This narrative review examines how alterations in gaze behaviour contribute to the emergence of CU traits across neurodevelopmental disorders (NDs), with a focus on autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and conduct disorder (CD). Across studies, elevated CU traits are associated with reduced fixations on the eye region, most consistently in response to fearful faces. ASD is associated with robust eye avoidance, ADHD with inhibitory and attentional control difficulties during face processing, and CD with atypical gaze allocation to negative emotional expressions such as fear and anger. These patterns appear amplified when CU traits co-occur with NDs. Competing explanatory accounts, including aberrant amygdala functioning, oculomotor disinhibition, and hostile attribution biases, each capture aspects of these patterns but fail to provide a unified explanation. Integrating developmental, neurobiological, and environmental perspectives, we propose that CU traits reflect a transdiagnostic developmental construct shaped by early attentional–emotional mechanisms, rather than a disorder-specific identity.

Background: This systematic review and meta-analysis evaluates the efficacy and safety of psilocybin-assisted psychotherapy (PAP) for adults with major depressive disorder (MDD). Methods: A PROSPERO-registered search (CRD42024561979) of CENTRAL, Scopus, PsycINFO, and MEDLINE (2010–2024) identified clinical trials assessing PAP. Risk of bias was assessed using RoB 2 for randomized controlled trials (RCTs), while non-randomized studies were appraised separately. Evidence certainty was evaluated using GRADE. Results: Ten trials were included; eight provided quantitative data. PAP was associated with large short-term reductions in depressive symptom severity. The overall pooled effect was large (d = 1.15, 95% CI 0.83–1.48), though within-subject designs yielded larger estimates (d = 1.63) than between-subject controlled comparisons (d = 0.96). Adverse events were transient and manageable, with no increased risk of serious adverse events on dosing days. Primary risk-of-bias concerns included functional unblinding. Conclusions: PAP may produce clinically meaningful, large short-term reductions in depressive symptoms. However, long-term efficacy remains understudied, and the overall certainty of evidence is low to moderate. Larger, rigorously blinded trials are required.

Atypical gaze patterns are consistently reported in autism, reflecting differences in social attention and interest. Gaze-tracking paradigms provide an objective way to quantify these differences and may serve as early indicators of autism. This diagnostic test accuracy systematic review and meta-analysis evaluated the performance of eye-tracking-based gaze measures in children. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy (PRISMA-DTA) guidance, studies published between 2015 and 2025 that compared gaze-tracking paradigms with standardized autism diagnoses were synthesized. Pooled diagnostic odds ratio (DOR), sensitivity, and specificity were estimated using random-effects and hierarchical summary receiver operating characteristic models. Risk of bias was assessed with QUADAS-2 and funnel plots. Seventeen studies ( n = 4,256) from six countries met the inclusion criteria. Tasks included social-geometric preference, motherese-nonsocial speech, and visual-orienting paradigms analyzed with rule-based or machine-learning methods. The pooled area under the hierarchical summary receiver operating characteristic curve (HSROC AUC) was 0.845; DOR 15.03 (95% CI 8.00–28.50); sensitivity 0.77 (95% CI 0.65–0.85); and specificity 0.80 (95% CI 0.75–0.84). Although heterogeneity was high ( I ² = 87.78%), effect directions were consistent. Dynamic social stimuli and higher-frequency tracking systems achieved the best performance. Gaze-tracking tests distinguished autistic and nonautistic children across diverse settings, supporting their potential role as a quantitative, observer-independent adjunct for early identification and clinical decision support. Lay Autism is a form of neurodiversity characterized by differences in social communication, sensory processing, and patterns of attention and interest, which often shape how autistic people look at and interpret the world around them. Eye-tracking technology records where a person looks on a screen and how long their gaze remains on elements, such as people, faces, or objects. Because it is objective and does not rely on language or complex instructions, eye-tracking may support earlier identification of autism. This study reviewed 17 research papers published between 2015 and 2025 that explored how eye-tracking distinguishes autistic and nonautistic children. Together, these studies included over 4,000 participants and compared attention to social scenes, like people talking or playing, with attention to nonsocial or geometric patterns. On average, eye-tracking correctly identified autism about 77% of the time and nonautistic children about 80% of the time, with the best results achieved with dynamic social videos and high-quality tracking cameras. These findings suggest that gaze-based measures capture meaningful differences in social attention and could complement existing diagnostic approaches through earlier, more objective assessment.

Background: Sarcopenia is a progressive muscle disorder associated with metabolic syndrome (MS), in which early impairments in muscle strength and quality precede muscle mass loss. Simple, non-invasive measures such as handgrip strength, estimated appendicular skeletal muscle mass (eASM), and phase angle (PA) may aid early detection, while adipokines link muscle dysfunction to metabolic regulation. Objective: In the present study, we aimed to evaluate the association between sarcopenia markers and PA in patients with MS. Methods: A cross-sectional study was conducted in patients with MS, at a third-level hospital in Mexico City. Sarcopenia was assessed by handgrip strength and eASM; body composition and PA were measured using bioelectrical impedance; and plasma adipokines were quantified by ELISA. Results: Seventy-four (mean age, 57.7 years; 75% female; BMI, 32.5 kg/m²) participants with MS were included. Handgrip strength correlated with eASM (r = 0.64; p < 0.01) and PA (rho = 0.43; p < 0.01), and eASM also correlated with PA (rho = 0.40; p < 0.01) and predicted higher PA values (OR = 2.74; p = 0.042). The sarcopenic subgroup had lower brachial circumference and plasma adiponectin. Conclusions: Sarcopenia is frequent in MS and associated with lower adiponectin, suggesting a vulnerable condition. Functional/structural markers of sarcopenia showed significant correlation with PA, whereas combined methods may enhance the early detection and management of muscle deterioration in metabolic disease.