Individuals of normal intelligence with autism spectrum disorders（ASD）tend to be diagnosed with ASD late in childhood or sometimes in adulthood, despite a persistent symptomatology. When such patients visit psychiatric clinics for co‒occurring psychiatric symptoms, the diagnostic procedure can be challenging due to a lack of accurate developmental information and a mixed clinical presentation. The same is true for those with subthreshold autistic symptoms. Although individuals with subthreshold ASD also have social adjustment difficulties of a similar degree to those with ASD, the relative clinical significance of this population is unclear. Here, data from a large national population sample of schoolchildren were examined to determine the psychiatric needs of children with threshold and subthreshold autistic symptoms. First, autistic symptoms or traits assessed by the Social Responsiveness Scale（SRS）, a quantitative behavioral measure, showed a continuous distribution in the general child population（n＝22,529）, indicating no evidence of a natural gap that could differentiate children diagnosed with ASD from subthreshold or unaffected children. Second, data from 25,075 children demonstrated that having threshold autistic symptoms predicted a high psychiatric risk, as indicated by higher scores on the Strengths and Difficulties Questionnaire（SDQ；odds ratio［OR］200.52,95％ confidence interval［CI］：152.12‒264.33）, and that having subthreshold autistic symptoms indicated the same（OR 12.78, 95％CI：11.52‒14.18）. Having threshold autistic symptoms predicted emotional problems（OR 20.19, 95％CI：17.00‒24.00）, as did having subthreshold autistic symptoms（OR 5.90, 95％CI：5.29‒6.58）. Third, among 2,250 children at a high psychiatric risk, most had threshold or subthreshold autistic symptoms（21 and 44％, respectively）. These findings have important implications for the comprehensive psychiatric and developmental evaluation and treatment of this patient population, whose diagnosis and treatment are often delayed, and a further in‒depth study is warranted.