Compliance with the standards across services
Compliance with SIGN 145
SIGN (Scottish Intercollegiate Guideline Network) 145. Assessment, Diagnosis and interventions for autism spectrum disorders is the national clinical guideline for autism spectrum disorders for healthcare professionals in Scotland. It provides evidence-based recommendations on how autism assessments should be conducted. This guideline ensures that the process is robust, consistent, and provides a high standard of care for all patients. It is the benchmark for a legitimate and high-quality diagnosis.
All autism diagnostic services in Scotland - regardless of whether they are NHS services or independent ones - should adhere to this standard.
Who is authorised to conduct autism assessments & make autism diagnoses
In Scotland, adult autism diagnosis is provided mainly by NHS multidisciplinary teams, but commissioned non-NHS providers may also deliver assessments under NHS oversight, and private independent clinics offer similar diagnostic services on a self-pay or insured basis. All these providers should use trained, registered clinicians administering evidence-based, multidisciplinary assessments guided by the Scottish clinical standards (SIGN 145) and employing recognised tools such as ADOS-2 and ADI-R.
NHS assessments
Diagnosis is carried out by specialist multidisciplinary teams within NHS Scotland, such as Community Mental Health Teams (CMHTs), Adult Neurodevelopmental Services (ANDS), or Learning Disability Services.
These teams include psychiatrists, clinical psychologists, speech and language therapists, and other trained autism assessment specialists registered with professional bodies such as the Health and Care Professions Council (HCPC).
Assessments follow SIGN 145 guideline and use gold-standard tools such as ADOS-2 (Autism Diagnostic Observation Schedule) and ADI-R (Autism Diagnostic Interview-Revised).
Referral is usually via a General Practitioner (GP) or mental health services, with an increasing number of structured referral pathways from community and psychological therapy teams.
NHS assessments typically involve multiple appointments, gathering developmental history (including from someone who knew the adult as a child), clinical observation, and detailed interviews to determine diagnosis and support needs.
Non-NHS providers commissioned by NHS
Some NHS boards in Scotland commission accredited non-NHS providers to deliver autism diagnostic assessments due to demand or for enhanced access.
These providers must adhere to the same clinical standards, guidelines, and use similar multidisciplinary teams and validated assessment tools.
They work under Scottish NHS contracts and report diagnostic outcomes through NHS channels.
Such arrangements ensure diagnostic consistency and allow flexibility to meet growing demand while maintaining quality.
Private independent diagnostic clinics
Private clinics in Scotland also offer adult autism diagnostic assessments, providing quicker access and more flexible scheduling than NHS routes.
These clinics employ qualified, registered clinicians (psychologists, psychiatrists, speech therapists) who use the same standard diagnostic protocols, including ADOS-2 and ADI-R.
Private assessments can be sought directly by individuals or recommended by GPs
Private services require payment from the individual or insurance, and post-diagnostic support may need to be sought separately
Notes:
Registered Nurse' ('RN'), 'Medical Practitioner' or 'Doctor', and HCPC-regulated titles (such as 'Occupational Therapist", 'Speech and Language Therapist', 'Practitioner Psychologist') are protected healthcare titles under the UK law, and it is a criminal offence for anyone, with intent to deceive, to falsely represent themselves as being registered or qualified to use these titles when they are not.
A non-clinician is not authorised to make clinical diagnoses.
Healthcare Improvement Scotland (HIS) - registration for independent healthcare services
An independent (i.e. non-NHS) diagnostic service in Scotland is, by definition, an "independent clinic" - and should be registered with Healthcare Improvement Scotland (HIS)*.
Independent clinics are defined in the National Health Service (Scotland) Act 1978 as:
Clinics that are not part of a hospital and from which a medical practitioner, dental practitioner, registered nurse, registered midwife or dental care professional (clinical dental technician, dental hygienist, dental nurse, dental technician, dental therapist, orthodontic therapist) provides a service, which is not part of the National Health Service. The term ‘service’ includes consultations, investigations and treatments.
Autism assessment and diagnosis = 'consultations, investigations'
You can check on HIS' register if an independent diagnostic service is registered with HIS. If it is not, it might be operating unlawfully - in which case you might wish to contact HIS.
Important: If an organisation providing autism diagnostic service operates other services in parallel with their diagnostic service (e.g., a care service and/or an autism support service), those other services would be registered with a different regulators than HIS - however, this does not waive their obligation to be registered with HIS for the diagnostic part of their operations.
*If an organisation is providing an autism diagnostic service only and exclusively under a contract with NHS, the service might be exempt from regulation by HIS. If you were referred via NHS pathway and did not need to pay for the service it would indicate the service was NHS-commissioned. You can contact HIS if you are unsure, and HIS should be able to help you determine if this is the case. If confirmed, the local NHS Board which commissioned the service and holds the contract with the service provider are responsible for the quality of the service and for handling complaints about it.