Related Experiment Video
Updated: Sep 29, 2026

Strategies for Assessing Autistic-Like Behaviors in Mice
Published on: September 20, 2024
Maladaptive behaviour in children and adolescents with Down's syndrome
1University of California - Los Angeles, Neuropsychiatric Institute, Los Angeles, California 90064, USA. edykens@mednet.ucla.edu
Background:
Although children with Down's syndrome (DS) are at lower risk for psychopathology than others with intellectual disability, they do show more problems than typically developing children. However, age-related trends in these problems remain unclear.
Methods:
The present authors examined age-related changes in the maladaptive behaviours of 211 children and adolescents with DS aged between 4 and 19 years (mean = 9.74 years). Most participants (n = 180) were recruited from families residing in the greater Los Angeles area, California, USA, while a minority (n = 31) were patients from a clinic specializing in the psychiatric management of people with DS. The participants were divided into four age groups: (1) 4-6 years, (2) 7-9 years, (3) 10-13 years and (4) 14-19 years.
Results:
Externalizing behaviours were lower across both the community and clinic samples, while internalizing behaviours were significantly higher in older adolescents aged between 14 and 19 years. Increases were found in withdrawal, seen in 63% of community-based adolescents, and 75% of clinic adolescents.
Conclusions:
Older adolescents with DS may show decreased externalizing symptoms and subtle increases in withdrawal. Possible relationships are discussed between these shifts and increased risks of later-onset depression and Alzheimer's disease in adults with DS.
Related Concept Videos
Oppositional Defiant Disorder
Diagnostic Criteria and...
Conduct Disorder
Autism Spectrum Disorder
These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.
Attention-Deficit/Hyperactivity Disorder
Diagnostic Criteria and Symptoms
To diagnose ADHD, symptoms must manifest before age 12 and be evident across multiple settings.
Introduction to Psychological Disorders
Deviant Behavior
Deviance in behavior refers to actions or thought patterns that significantly diverge from societal norms or...
Modeling in Therapy
Participant Modeling
Participant modeling involves therapists demonstrating calm and effective behaviors in situations...
