###### Created: 2023-01-28 10:06 ###### Areas & Topics: #medicine #disability ###### Note Type: #permanent ###### Connected to: [[Learning Disabilities]] ### Definition - Autism Spectrum Disorder is a lifelong form of neurodevelopmental disorder (a condition which affects the development of the nervous system). - Other examples of neurodevelopmental disorders include [[Learning Disabilities]], ADHD, Tic disorders and specific learning disorders. - ASD is characterised by persistent difficulties in social interaction and communication, and stereotypic (rigid and repetitive) behaviours, resistance to change or restricted interests. - Asperger Syndrome was a term previously used to describe people who displayed features of ASD with normal or above average intelligence and who did not have learning disabilties, but this term has now been removed to just be part of ASD instead. ### Epidemiology - The prevalence of ASD is estimated to be about 1 in 68. - It seems to be becoming more prevalent but the reasons for this are unknown. - ASD is 3 to 4 time more common in males (but this may be due to underdiagnosis in females). - ASD is highly associated with other neurodevelopmental and mental health disorders. - At least one associated mental health disorder occurs in approximately 70% of those with ASD. - ADHD is seen in 50% of patients with ASD. - Learning Disabilities are seen in 45% of patients with ASD. ### Aetiology - The cause of ASD has yet to be fully understood, but it is thought to have both genetic and environmental links. - There appears to be a genetic link as there is higher risk of ASD between siblings and twins. - Genetic conditions such as Down syndrome, Rett Syndrome and Fragile X syndromes have links to ASD. - Environmental factors such as prenatal infection, perinatal complications and exposure to toxins or teratogens also seem to be linked. - There could also be epigenetic causes due to these factors, but this is only theorised. ### Clinical Features - ASD has a wide range of clinical features which can have varying impact on each individual. - The clinical features of ASD might also change depending on what age the patient is currently. - The clinical features of ASD are based on persistent difficulty with social interaction/communication and restricted or repetive behaviours or thinking. In adults, features of ASD are mainly seen as - Reduced or unusual social interaction/communcation - Unusual restricted or repetitive behaviour - Persistent throughout their everyday life In children, features of ASD are mainly seen as: - Difficulties with speech for their level of development - Reduced or unusual social interaction/communcation - Unusual restricted or repetitive behaviour - Persistent throughout their everyday life The list below goes through the full list of features for clnical features of ASD in adults ###### Impaired social communication and interaction This includes both verbal and non-verbal communication skills Delays or deviations in language development are one of the most common findings by parents and caregivers in the presentation of ASD. There are various domains in social communication that may be affected including: - Social-emotional reciprocity: ability to engage in social interactions between two or more people - Nonverbal communication: ability to use and interpret nonverbal forms of communication (e.g. facial gestures) - Pragmatic communication: ability to select the rights words for the situation - Developing and sustaining friendships The full list of issues with social communication can include: - Atypical eye contact (staring at people for too long or not maintaining eye contact) - Intrusion into others’ personal space (standing too close to someone else, talking too loud, or touching people inappropriately) or becoming obsessed with a person to an intrusive extent - Reduced interest in socialising - Social anxiety - Loneliness (and risk of depression) - Social naïveté and vulnerability to exploitation - Bluntness or lack of diplomacy; unable to tell white lies; reduced empathy - Lack of social awareness. - Difficulties in the following areas: Understanding others’ behaviour, motives, and intentions Reading other people’s facial expressions or vocal intonation Taking turns in conversation or tendency towards monologue; making small talk or maintaining a conversation Reading between the lines or picking up hints Seeing things from another person’s perspective Resolving conflict Anticipating what might offend others Keeping track of what the listener or reader needs to know Making or keeping friends; understanding other people’s expectations Conforming Judging what might be relevant or irrelevant to others Coping with or interacting in social groups Coping with ambiguity in language ###### Restricted, repetitive behaviours This refers to a series of behaviours that form the hallmark of ASD These behaviours can be very restricting and impact the ability to sustain relationships and engage in social activities. Often, when these behaviours are restricted or blocked it can lead to significant anxiety, aggression and/or worsening behaviour patterns. There are various different behaviours that may be observed: - Stereotyped and repetitive motor movements (e.g. flapping hands, rocking) - Stereotyped and repetitive speech (e.g. echolalia - repetition of words spoken by another individual) - Insistence on sameness (e.g. always eating particular foods in a particular order) - known as cognitive rigidity - Resistance to change and preferance for repetition and routine (e.g. change leads to anxiety, temper tantrums) - Restricted/fixated interests (e.g. preoccupation with unusual objects, often with intense, unusual focus) - Abnormal response to sensory stimuli (e.g. refusal to eat food with certain texture) - Preference for predictability and predictable events (watching washing machines spinning or trains going down tracks) - Being extremely passive if an activity of interest is not available or initiated by someone else - Need for clarity and expressing a pedantic request for precision and avoiding ambiguity - Avoiding crowded places - Difficulties multi-tasking; doing one thing at a time ### Diagnosis - ASD diagnosis is done by a speciailist and so you should refer if you see a patient with suspected features of ASD. - It is important to note that ASD can coexist with a large array of neurodevelopmental and psychiatric disorders, so a thorough elimination of other differentials should be considered before referral NICE says to consider assessment for possible ASD when a person has: One or more of the following: - Persistent difficulties in social interaction. - Persistent difficulties in social communication. - Stereotypic (rigid and repetitive) behaviours, resistance to change, or restricted interests. AND One or more of the following: - Problems in obtaining or sustaining employment or education. - Difficulties in initiating or sustaining social relationships. - Previous or current contact with mental health or learning disability services. - A history of a neurodevelopmental condition (including learning disabilities and attention deficit hyperactivity disorder) or mental disorder. ### Resources https://www.ncbi.nlm.nih.gov/books/NBK525976/ https://app.pulsenotes.com/specialities/psychiatry/notes/autism-spectrum-disorder https://cks.nice.org.uk/topics/autism-in-adults/ https://cks.nice.org.uk/topics/autism-in-children/