Genetics of child aggression, a systematic review

Area of Science:

• Child psychiatry and developmental neuroscience
• Behavioral genetics and molecular psychiatry

Background:

• Childhood aggression is a prevalent behavioral issue leading to psychiatric referrals.
• Genetic factors account for approximately half of the variance in childhood aggression.
• The precise biological mechanisms and gene-environment interactions underlying aggression are not fully understood.

Purpose of the Study:

• To systematically review existing research on the genetics of childhood aggression, independent of psychiatric diagnosis.
• To provide an overview of studies examining genetic influences on aggressive behavior in youth.

Main Methods:

• Systematic literature search of PubMed, PsycINFO, and MEDLINE databases.
• Inclusion of studies using keywords related to aggression, genes, and child/youth populations.
• Extraction and quality assessment of 87 relevant studies from an initial yield of 652.

Main Results:

• Candidate gene studies, particularly those focusing on MAOA, DRD4, and COMT, are prevalent.
• Increasing use of genome-wide association and epigenetic study designs is noted.
• Inconclusive findings regarding genetic main effects and interactions are common due to moderate study sizes, variable assessment methods, and inconsistent variant categorizations.
• Most studies focus on European populations, with a majority involving male participants.

Conclusions:

• Current research on the genetics of childhood aggression yields inconclusive results.
• Further research with larger, diverse samples, standardized assessments, and clear phenotype definitions is crucial.
• Exploring varied methodologies like epigenetics, transcriptomics, and longitudinal studies is essential for elucidating the biological underpinnings of aggression.