Synopsis
Recognise lifelong autistic features in adults, arrange a developmentally informed specialist assessment, adapt communication and sensory environments, and treat coexisting distress without trying to medicate core autism.
- Consider autism when lifelong social-communication differences and restricted, repetitive or highly focused patterns are associated with functional difficulty, even if the adult learned to mask them.
- For adults without moderate or severe learning disability, NICE advises considering AQ-10; a score of six or more, or persisting clinical suspicion, supports comprehensive assessment rather than making the diagnosis.
- Comprehensive assessment uses developmental history, current functioning, direct observation, physical and mental-health review, sensory profile and differential diagnosis, ideally through a specialist multidisciplinary team.
- Ask the person which identity language they prefer and describe strengths, needs and environments rather than judging eye contact, empathy or speech against stereotypes.
- Sensory hyper- or hypo-sensitivity to sound, light, touch, smell, taste, temperature, pain and internal bodily signals can shape distress, healthcare access and daily function.
- Offer concrete communication, predictability, reduced sensory load, processing time and reasonable adjustments; psychological interventions for coexisting disorders require autism-informed adaptation.
- Do not use antipsychotics, antidepressants, anticonvulsants or exclusion diets to manage core autistic features. For antipsychotic treatment of severe behaviour that challenges, a specialist identifies the target, monitors quality of life and adverse effects, reviews at three to four weeks and stops at six weeks without clinically important response.
Key red flags
A rapid departure from lifelong communication, movement, sleep, eating, continence or interests requires urgent assessment for physical illness, neurological change and mental disorder.
Marked immobility, posturing, stupor, autonomic change, severe excitement or abrupt loss of speech raises possible catatonia and needs specialist same-day assessment.
Self-injury, suicidal intent, exploitation, domestic abuse, homelessness or inability of the current support arrangement to maintain safety needs a coordinated crisis and safeguarding plan.
Restraint, seclusion or heavy sedation that follows avoidable noise, uncertainty or communication failure must be reviewed as a patient-safety and restrictive-practice concern.
Investigation priorities
Establish early social-communication, behavioural, sensory and adaptive patterns and their course.
Management branches
Lifelong social-communication and restricted-pattern features are associated with functional difficulty or service contact.
- Take a developmental and current functional history, ask about masking and sensory needs, and explore learning disability, ADHD, mental illness and physical health.
- Consider AQ-10 where appropriate, reading it aloud if needed, but refer for comprehensive assessment when the score is six or above or clinical suspicion persists.
- Make interim communication and environmental adjustments immediately rather than waiting for diagnostic completion before improving access.