Centre for Addiction and Mental Health, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
Offord Centre for Child Studies, McMaster University, Hamilton, Ontario, Canada.
JAMA Psychiatry. 2015 Mar;72(3):276-83. doi: 10.1001/jamapsychiatry.2014.2463.
Symptom severity and adaptive functioning are fundamental domains of the autism spectrum disorder (ASD) phenotype. To date, the longitudinal association between these 2 domains has not been examined.
To describe the developmental trajectories of autistic symptom severity and adaptive functioning in a large inception cohort of preschool children with ASD.
DESIGN, SETTING, AND PARTICIPANTS: The sample consisted of 421 newly diagnosed preschool children with ASD 2 to 4 years old (355 boys; mean age at study enrollment, 39.87 months) participating in a large Canadian multisite longitudinal study (Pathways in ASD Study). Prospective data collected at 4 points from time of diagnosis to age 6 years were used to track the developmental trajectories of children.
Autistic symptom severity was indexed using the Autism Diagnostic Observation Schedule. Adaptive functioning was indexed using the Vineland Adaptive Behavior Scales, Second Edition.
Two distinct trajectory groups provided the best fit to the autistic symptom severity data. Group 1 (11.4% of the sample) had less severe symptoms and an improving trajectory (P < .05), whereas group 2 (88.6% of the sample) had more severe symptoms and a stable trajectory. Three distinct trajectory groups provided the best fit to the adaptive functioning data. Group 1 (29.2% of the sample) showed lower functioning and a worsening trajectory, group 2 (49.9% of the sample) had moderate functioning and a stable trajectory, and group 3 (20.9% of the sample) had higher functioning and an improving trajectory (P < .05). Cross-trajectory overlap between the autistic symptom severity and adaptive functioning groups was low (φ = 0.13, P < .05). Sex was a significant predictor of autistic symptom severity group membership and age at diagnosis, and language and cognitive scores at baseline predicted membership in adaptive functioning trajectories. Trajectories of both symptom severity and adaptive functioning predicted several different outcomes at age 6 years.
Findings confirm the heterogeneous nature of developmental trajectories in ASD. Change in adaptive functioning suggests that improvement is possible in roughly 20% of the sample. Autistic symptom severity appears to be more stable, with roughly 11% of the sample showing a marked decrease in symptom severity. During the preschool years, there appears to be only a small amount of "yoking" of developmental trajectories in autistic symptom severity and adaptive functioning. It is imperative that a flexible suite of interventions that target both autistic symptom severity and adaptive functioning should be implemented and tailored to each child's strengths and difficulties.
症状严重程度和适应功能是自闭症谱系障碍（ASD）表型的基本领域。迄今为止，这两个领域之间的纵向关联尚未被研究过。
描述 ASD 学龄前儿童大样本中自闭症症状严重程度和适应功能的发展轨迹。
设计、地点和参与者：该样本包括 421 名新诊断为 ASD 的 2 至 4 岁学龄前儿童（355 名男孩；研究入组时的平均年龄为 39.87 个月），他们参加了一项大型加拿大多地点纵向研究（自闭症途径研究）。在从诊断到 6 岁的 4 个时间点收集前瞻性数据，以跟踪儿童的发展轨迹。
自闭症症状严重程度使用自闭症诊断观察量表（Autism Diagnostic Observation Schedule）进行评估。适应功能使用第二版 Vineland 适应行为量表（Vineland Adaptive Behavior Scales，Second Edition）进行评估。
两个不同的轨迹组为自闭症症状严重程度数据提供了最佳拟合。组 1（样本的 11.4%）症状较轻，呈上升趋势（P<0.05），而组 2（样本的 88.6%）症状较重，呈稳定趋势。三个不同的轨迹组为适应功能数据提供了最佳拟合。组 1（样本的 29.2%）表现出较低的功能和恶化轨迹，组 2（样本的 49.9%）具有中等功能和稳定轨迹，组 3（样本的 20.9%）具有较高的功能和改善轨迹（P<0.05）。自闭症症状严重程度和适应功能轨迹组之间的交叉轨迹重叠较低（φ=0.13，P<0.05）。性别是自闭症症状严重程度组归属和诊断时年龄的重要预测因素，基线时的语言和认知评分预测了适应功能轨迹的归属。症状严重程度和适应功能的轨迹都预测了 6 岁时的多种不同结果。
研究结果证实了 ASD 中发展轨迹的异质性。适应功能的变化表明，约 20%的样本可能有明显改善。自闭症症状严重程度似乎更稳定，约 11%的样本症状严重程度明显下降。在学龄前，自闭症症状严重程度和适应功能的发展轨迹之间似乎只有少量的“联合”。至关重要的是，应该实施一套灵活的干预措施，针对自闭症症状严重程度和适应功能，并根据每个孩子的优势和困难进行调整。
