NHS AI Digital Mental Health Triage -- Depression and Anxiety Assessment

MHRA Class IIa SaMD

AI that aids therapist step allocation is Class IIa (assists clinical decision).

Class IIa pathway

UK Notified Body technical file (BSI Assurance UK), IEC 62304 Class B.

Conversational AI constraints

• 1AI never diagnoses (AI guides through validated questionnaire -- PHQ-9, GAD-7 -- it does not interpret results),
• 2AI never recommends treatment (AI produces scored questionnaire results for therapist review -- not a treatment recommendation),
• 3AI safety escalation (if patient expresses suicidal ideation during assessment -- immediate safety escalation to crisis service with human response),
• 4therapist review always required (AI triage aids step allocation, therapist confirms step),
• 5override mechanism (therapist can override AI-suggested step -- all overrides reviewed by clinical supervisor). PHQ-9 and GAD-7

Conversational Interface

Conversational AI for PHQ-9 and GAD-7: (1) NHS Login P5 authentication (patient authenticates before assessment), (2) conversational UI (React + WebSocket -- natural language question flow rather than form-filling), (3) PHQ-9 administration (9 validated depression questions -- AI presents in natural language, patient responds in natural language, AI maps response to PHQ-9 Likert scale 0-3), (4) GAD-7 administration (7 validated anxiety questions -- same pattern), (5) safety question (PHQ-9 Q9 -- thoughts of self-harm -- if positive, immediate safety escalation workflow).

NICE ESF Tier 2

AI informs clinical discussion rather than making independent decision -- compliant with Tier 2 evidence standard.

NICE evidence requirements for Tier 2

user acceptability, clinical safety, technical security (DTAC) -- no full clinical trial required.

AI Safety Escalation and Crisis Management

• Mental health AI safety -- critical design: (1) safety keyword detection (if patient types crisis keywords -- suicidal, self-harm, harm -- during assessment: immediate escalation), (2) safety escalation workflow (AI assessment pauses -- patient shown crisis resources: Samaritans 116 123, Crisis Text Line 85258, A&amp
• E), (3) therapist crisis notification (PagerDuty alert to duty therapist when crisis keywords detected -- therapist acknowledges within 30 minutes), (4) crisis assessment recording (all crisis escalations logged -- clinical supervisor review within 24 hours), (5) PHQ-9 Q9 positive protocol (Q9 score &gt
• 0 -- follow-up safety assessment questions -- clinical triage pathway, not generic AI response).

DCB0129

• crisis escalation is the primary clinical safety feature -- DCB0129 hazard log item 1.
• NHS DTAC Domain 1 --

NHS DTAC Domain 1 for mental health AI

• 1ICO DPIA mandatory (AI assessment of mental health = systematic profiling of special category data under Article 35),
• 2lawful basis (healthcare treatment -- Article 9(2)(h) -- IAPT is NHS healthcare provision),
• 3data minimisation (only PHQ-9/GAD-7 scores and session metadata stored -- not verbatim conversation transcripts),
• 4separate database schema (mental health AI assessment data encrypted with separate KMS key -- most sensitive NHS data category),
• 5retention (

NHS guidance

mental health records 8 years post-discharge).

ICO mental health guidance

clinical notes can be withheld from Subject Access Request if disclosure would harm patient -- AI assessment records are subject to the same protection.