Child Development Disorders, PervasiveAutistic DisorderAsperger SyndromeFetal Alcohol Spectrum DisordersSocial BehaviorLanguage Development DisordersAdolescent BehaviorStereotypic Movement DisorderRegression (Psychology)Stereotyped BehaviorDevelopmental DisabilitiesCommunication DisordersChild BehaviorAdolescent PsychologyAttention Deficit Disorder with HyperactivityTheory of MindParentsIntelligenceIntellectual DisabilityHealth Planning CouncilsSiblingsEarly Intervention (Education)Interpersonal RelationsSocial Behavior DisordersCase-Control StudiesBrainMental DisordersPlay and PlaythingsEndophenotypesIntelligence TestsNeuropsychological TestsLanguage TestsSocial PerceptionVerbal BehaviorMagnetic Resonance ImagingPsychiatric Status Rating ScalesLanguage DisordersLanguage DevelopmentChild Behavior DisordersBipolar DisorderDiagnostic and Statistical Manual of Mental DisordersAge FactorsChild DevelopmentQuestionnairesNonverbal CommunicationFaceGenetic Predisposition to DiseaseAnxiety DisordersDisabled ChildrenFacial ExpressionImitative BehaviorPersonality AssessmentParent-Child RelationsChild LanguageAttentionLongitudinal StudiesMothersPsychological TestsSeverity of Illness IndexInfant BehaviorAnalysis of VariancePrevalenceCommunicationRisk FactorsChild PsychiatryCompulsive BehaviorWechsler ScalesMacrocephalyBrain MappingAdolescent DevelopmentFragile X SyndromeCognitionDNA Copy Number VariationsIrritable MoodPregnancyCognition DisordersLanguage TherapyBehavior TherapyLanguageNeural PathwaysComorbidityPsychometricsEmotionsPhenotypeMood DisordersSpeech DisordersAttention Deficit and Disruptive Behavior DisordersEducation, SpecialAdolescent Health ServicesRett SyndromeChild WelfareSpeech TherapyCross-Sectional StudiesPeer GroupUnited StatesPsychotropic DrugsEarly DiagnosisCell Adhesion Molecules, NeuronalGroomingPrenatal Exposure Delayed Effects