TY - JOUR
T1 - Second-to-fourth digit ratio (2D:4D) in psychiatric disorders
T2 - A systematic review of case-control studies
AU - Fusar-Poli, Laura
AU - Rodolico, Alessandro
AU - Sturiale, Serena
AU - Carotenuto, Bianca
AU - Natale, Antimo
AU - Arillotta, Davide
AU - Siafis, Spyridon
AU - Signorelli, Maria Salvina
AU - Aguglia, Eugenio
N1 - Publisher Copyright:
© 2021 Korean College of Neuropsychopharmacology. All rights reserved.
PY - 2021/2
Y1 - 2021/2
N2 - The second-to-fourth digit ratio (2D:4D) is an indirect, retrospective, non-invasive measure that correlates negatively with intrauterine exposure to testosterone. The present meta-analysis aimed to evaluate if 2D:4D differs between patients with psychiatric disorders and controls. In September 2019, we searched in Web of Knowledge, PsycINFO, Embase, and CINHAL, and retrieved 619 papers. We finally included 43 case-control studies which compared the 2D:4D ratio of patients with autism spectrum disorder (ASD) (n = 16), schizophrenia (n = 8), gender non-conformity (n = 7), addictions (n = 5), attention deficit-hyperactivity disorder (ADHD) (n = 4), mood disorders (n = 2), and intellectual disability (n = 1) to non-clinical controls. Meta-analyses showed that, overall, psychiatric patients had lower 2D:4D than healthy controls (n = 43, overall sample = 9,484, mean difference = -0.0056, 95% confidence interval from -0.0093 to -0.002, I2= 74%), with more pronounced differences in the right hand, males, and children. Considering psychiatric disorders individually, significant differences were found in the ASD, ADHD, and addictions groups, in which 2D:4D was significantly lower than healthy controls. Conversely, the right hand of males with schizophrenia showed higher 2D:4D than healthy controls. No other significant differences were detected. Although our results need to be cautiously interpreted and find limited applications in clinical practice, they may suggest that 2D:4D is altered in some psychopathological conditions, underlining the role of prenatal exposure to sex steroids in the etiology of psychiatric disorders.
AB - The second-to-fourth digit ratio (2D:4D) is an indirect, retrospective, non-invasive measure that correlates negatively with intrauterine exposure to testosterone. The present meta-analysis aimed to evaluate if 2D:4D differs between patients with psychiatric disorders and controls. In September 2019, we searched in Web of Knowledge, PsycINFO, Embase, and CINHAL, and retrieved 619 papers. We finally included 43 case-control studies which compared the 2D:4D ratio of patients with autism spectrum disorder (ASD) (n = 16), schizophrenia (n = 8), gender non-conformity (n = 7), addictions (n = 5), attention deficit-hyperactivity disorder (ADHD) (n = 4), mood disorders (n = 2), and intellectual disability (n = 1) to non-clinical controls. Meta-analyses showed that, overall, psychiatric patients had lower 2D:4D than healthy controls (n = 43, overall sample = 9,484, mean difference = -0.0056, 95% confidence interval from -0.0093 to -0.002, I2= 74%), with more pronounced differences in the right hand, males, and children. Considering psychiatric disorders individually, significant differences were found in the ASD, ADHD, and addictions groups, in which 2D:4D was significantly lower than healthy controls. Conversely, the right hand of males with schizophrenia showed higher 2D:4D than healthy controls. No other significant differences were detected. Although our results need to be cautiously interpreted and find limited applications in clinical practice, they may suggest that 2D:4D is altered in some psychopathological conditions, underlining the role of prenatal exposure to sex steroids in the etiology of psychiatric disorders.
KW - Attention deficit disorder with hyperactivity
KW - Autism spectrum disorder
KW - Mental disorders
KW - Meta-analysis
KW - Substance addiction
KW - Testosterone
UR - http://www.scopus.com/inward/record.url?scp=85101386742&partnerID=8YFLogxK
U2 - 10.9758/CPN.2021.19.1.26
DO - 10.9758/CPN.2021.19.1.26
M3 - Review article
AN - SCOPUS:85101386742
SN - 1738-1088
VL - 19
SP - 26
EP - 45
JO - Clinical Psychopharmacology and Neuroscience
JF - Clinical Psychopharmacology and Neuroscience
IS - 1
ER -