Establishing the relationship between ADHD and emotional facial expression recognition deficit: a systematic review
Maria Olaya Galindo1, Oscar Vargas Cifuentes1, Alberto Vélez Van-Meerbeke1, Claudia Talero-Gutiérrez1
1Neuroscience research group, Universidad del Rosario, Escuela de Medicina y Ciencias de la Salud
Objective:

This review aims to determine if there is a deficit in facial emotion recognition in children, adolescents and adults with attention-deficit/hyperactivity disorder.

Background:
Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inappropriate and persistent patterns of inattention, hyperactivity and impulsivity. Emotional regulation deficits have been described in people with ADHD. Yet, no causality has been described regarding facial emotion recognition (FER) deficit in ADHD, and there are no studies that evaluate the mentioned deficit through childhood, adolescence and adulthood. 
Design/Methods:
Comprehensive database search was performed until September 2022 using PubMed, Scopus, ScienceDirect, Embase, Medrxiv and Google Scholar databases. Studies with children, adolescents or adults with isolated ADHD or comorbidities, control group without ADHD, and evaluation of FER task were included. Systematic reviews, editorial letters, book chapters, languages different from english or spanish, publications before the last 5 years, and evaluation with tasks that were not FER were excluded. Quality was assessed using Joanna Briggs Institute Quality tools.
Results:
A total of 385 studies were found, from which 12 were included. The evaluated patients had ages between 6 to 37.1 years. Most studies evidenced a FER deficit that can either be associated specifically to ADHD (n=5) or to secondary comorbidities as first-order theory of mind, deficits in expressive vocabulary or working memory skills, anxiety, oppositional and inattention symptoms (n=3). The remaining research did not show a FER deficit (n=4), but displayed longer latency in responses of ADHD groups compared to controls.
Conclusions:
There is a high heterogeneity between the studies as there is no standard criteria for the evaluation of FER. Nevertheless,there are difficulties in FER among children, adolescents and adults with ADHD in comparison to controls. FER deficit may be related specifically to ADHD or secondary to associated symptoms and comorbidities.
10.1212/WNL.0000000000203927