Detecting subgroups in children diagnosed with pervasive developmental disorder - not otherwise specified

Area of Science:

• Child psychology
• Developmental neuroscience
• Clinical psychology

Background:

• Pervasive Developmental Disorder--Not Otherwise Specified (PDD-NOS) is a complex diagnosis.
• Understanding developmental trajectories within PDD-NOS is crucial for early intervention.
• Subgroup identification may clarify diagnostic heterogeneity.

Purpose of the Study:

• To identify distinct subgroups within a PDD-NOS sample at age 2.
• To examine the diagnostic outcomes of these subgroups at age 4.
• To explore the role of specific symptoms, like repetitive behaviors, in predicting outcomes.

Main Methods:

• Hierarchical cluster analyses were applied to data from children diagnosed with PDD-NOS at age 2.
• Cognitive scores, autism symptoms, social/communication skills, and repetitive behaviors were assessed.
• Diagnostic outcomes at age 4 were compared across identified clusters.

Main Results:

• Three distinct subgroups emerged at age 2.
• Cluster 1 (few autism symptoms, high cognition) showed significant improvement, with 60% no longer meeting PDD criteria at age 4.
• Cluster 2 (more autism symptoms, lower cognition) had 89.5% meeting Autism Spectrum Disorder (ASD) criteria at age 4.
• Cluster 3 (lowest cognition, impaired social/communication, no repetitive behaviors) had 60% diagnosed with Autistic Disorder at age 4.

Conclusions:

• Subgrouping PDD-NOS at age 2 can predict later diagnostic outcomes.
• The presence and severity of autism symptoms and cognitive function are key predictors.
• The diagnostic criteria in DSM-5, particularly the emphasis on repetitive behaviors, warrant further investigation in light of these findings.