Autism is a representative disorder of pervasive developmental disorders, with the main symptoms being impaired social interaction, impaired communication, narrow interests, and stereotypical repetitive behavioral patterns. Autism Spectrum Disorder (ASD) is a broad definition of autism based on the core symptoms of autism. ASD includes both typical and atypical autism, as well as Asperger’s syndrome, borderline autism, and autistic suspicion, ASD is diagnosed when a child, youth, or adult behaves in a manner that meets the diagnostic criteria of the ICD-10 or DSM-IV and causes significant functional impairment. The core symptoms usually manifest early in childhood, especially when there is a change in the environment, such as starting kindergarten or elementary school. It is estimated that more than 1% of children have ASD, and the disorder can haunt the patient for the rest of his or her life, affecting the patient and his or her family. Once diagnosed, patients and their families experience a strong emotional impact, but can also reap great relief from the follow-up care and treatment, and a positive corrective effect on the patient’s life course. To this end, the National Institute for Health and Clinical Excellence (NICE) has developed this guideline based on the best research evidence to provide practical advice on the identification, referral and diagnosis of people with ASD. Identification A local multi-agency autism organisation should be established, bringing together staff from child health and mental health services, education, social care, parents, carer service users and volunteers, and should have an overall director. The main objectives of the organisation are: to promote the early detection of signs and symptoms of ASD through training; to ensure that relevant professionals can provide effective diagnostic services through this route; to enable young people to access follow-up services after diagnosis; and to enable the collection of relevant data and statistics. The guidelines provide recommendations for laypersons to identify ASD: be alert for developmental or behavioral problems in children, but do not overlook other possible disorders; be cautious about developmental or behavioral problems identified by patients or their families; value peer recommendations; the clinical presentations described in the guidelines are common and not all can be covered; abnormal signs and symptoms should be present throughout a patient’s development, but are often overlooked early on. Carefully screen for masked ASD, such as intellectual disability, verbal bravado, and past negative diagnoses; pay attention to cultural differences and to patients’ understanding and use of their native language; and pay attention to psychological support. Referral Pay attention to signs and symptoms associated with the child or adolescent and their duration, the site of the episode, the impact on the patient and family, and ASD susceptibility factors. Refer patients directly to the ASD team for language or social deterioration in young children under 3 years of age, whereas patients of any age who present with these signs or motor deterioration in children or young adults over 3 years of age need to be referred first to a pediatrician or pediatric neurologist. Children and adolescents who are not yet showing significant signs or symptoms but are still at high risk should be monitored for observation and other possibilities should be considered. What are the risk factors for ASD? ASD in a sibling; congenital defects with central nervous system malformations or functional abnormalities, including cerebral palsy; prematurity at less than 35 weeks of gestational age; parental schizophrenia or affective disorder; maternal valproate use during pregnancy; mental retardation; neonatal encephalopathy or epileptic encephalopathy, including infantile spasms; chromosomal disorders, such as fragile X syndrome; myotonic dystrophy; neurofibromatosis; tuberous sclerosis disease. ASD diagnostic evaluation begins within three months of patient referral and each patient is assigned a case coordinator whose primary function is to act as a representative of the ASD team to communicate with the patient or guardian and to arrange for the patient’s visit. (2) Detailed questions about the child or youth’s family life, education, and social experiences. (3) Developmental history, with special attention to developmental and behavioral characteristics that meet the diagnostic criteria of the ICD-10 and DSM-IV. (4) Assess the patient’s social and communication skills and behaviors through interaction and observation, with particular attention to characteristics that meet the diagnostic criteria for ICD-10 and DSM-IV. (5) The patient’s prenatal and perinatal medical history, family history, and past and present health status. (6) Physical examination, with special attention to check for tuberous sclerosis and neurofibromatosis, self-harm or abuse, and megalencephaly or microcephaly. (7) Perform differential diagnosis. (8) Check for systemic assessment of co-morbidities such as neurodevelopmental disorders, psychiatric and behavioral abnormalities, developmental degeneration, and others. (9) Create a profile covering the patient’s strengths, skills, impairments, and needs that can be used to develop a needs-based management program. (10) Communicate with the patient’s guardian regarding the results of the assessment and, if necessary, inform the patient himself. The guidelines recommend making full use of all sources of information to make clinical judgments based on ICD-10 and DSM-IV criteria. Do not rely on any one ASD-specific diagnostic tool alone to confirm the diagnosis. If diagnostic uncertainty remains after evaluation, regular follow-up is needed to obtain updated information. Consider referring the patient to a higher-level ASD treatment team if necessary. Medical tests Do not follow any medical investigations as part of the diagnostic evaluation for ASD. Consider genetic testing if there is evidence of a specific variant phenotype, congenital malformation, and/or intellectual disability, and consider an EEG if epilepsy is suspected. However, consideration of these above tests is to be done on an individual basis, based on physical examination, clinical judgment and the patient’s profile. Specific interventions for core features of ASD Psychosocial interventions are interventions for the core symptoms of ASD, where the guardian engages in play-based interactions with the patient under professional guidance to promote communication skills in the child or youth. However, interventions for core symptoms of ASD are not appropriate for antidepressant, anticonvulsant, antipsychotic, and exclusion diets. Interventions for Challenging Behaviors First assess factors that would promote challenging behaviors, such as communication difficulties, psychiatric co-morbidities, and environmental factors, and then work with the patient and guardian to develop a care plan and exclude these interfering factors. Once the patient has developed challenging behaviors, actively exclude existing stimuli and improve the care plan; if this is not successful, consider consulting with a supervising physician and conducting a multifaceted review. If the patient does not have psychiatric co-morbidities, then psychosocial interventions should be the first-line treatment plan, including: clear targeting of target behaviors; the ultimate goal of improving the patient’s quality of survival; assessment of the impact of environmental factors; the need to integrate the patient’s developmental level and co-morbidities when developing a clear intervention strategy; specialized time scales to achieve intervention goals; the need to assess target behaviors both before and after intervention; and interventions that encompass the patient’s various life circumstances; and guardians and physicians need to agree on how to implement interventions. If psychosocial interventions or other measures are not sufficient to control the patient’s challenging behavior, antipsychotic medication needs to be considered and monitored by a pediatrician or psychiatrist. Life Skills Interventions Provide support for management strategies for the child or youth to promote the development of their ability to live, work, and participate in recreational activities. Interventions for co-morbidities Provide CBT interventions for patients with anxious ASD who have language and cognitive skills; group or individual CBT therapy may be considered. Patients presenting with sleep problems need to be evaluated for sleep patterns, quality, environmental factors, and impact, with collaboration with guardians to remove distractions to ensure adequate sleep time, and with attention to diagnosing the presence of obstructive apnea syndrome. Non-pharmacologic interventions are preferred to address the patient’s sleep problems in non-essential situations. Contraindications to interventions Do not use neurofeedback to manage speech problems in patients with ASD; do not use auditory integration training to manage speech problems in patients with ASD; do not use omega-3 fatty acids to manage sleep problems in patients with ASD; and do not use secretin, chelation therapy, or hyperbaric oxygen therapy to manage patients with ASD.