About this trial
This study is a pivotal, randomised, controlled, non-inferiority trial evaluating "Nook," an AI-delivered, neurosymbolic, clinician-supervised digital psychological intervention for depression and anxiety, compared with standard cognitive behavioural therapy (CBT). The trial will recruit 400 participants aged 16-64 years in the UK with moderate depression and/or anxiety symptoms. Participants will be randomised to receive either Nook or therapist-delivered CBT.
The primary objective is to determine whether Nook is non-inferior to CBT in reducing depression and anxiety symptoms, measured using the PHQ-9/PHQ-A and GAD-7 scales. Secondary outcomes include quality of life, functional impairment, sleep quality, treatment engagement, participant satisfaction, safety outcomes, and exploratory health economic measures.
The intervention incorporates clinician oversight and predefined escalation pathways for suicidality and clinical deterioration. Outcomes will be analysed using longitudinal mixed-effects models under an intention-to-treat framework.
Eligibility criteria
Qualifiers
Have symptoms of Generalized Anxiety Disorder (GAD) and/or symptoms of --•Major Depressive Disorder (MDD) as the primary reason for seeking treatment (formal diagnosis not required).(as determined by a Psychological Well-being Practitioner).
Depression: PHQ-9 (or PHQ-A for young persons) total score between 10 and 19, corresponding to moderate to moderately-severe symptoms, and/or
Anxiety: GAD-7 total score between 8 and 21, corresponding to mild to severe symptoms.
Aged 16-64 years
Disqualifiers
Depression: PHQ-9 (or PHQ-A for young persons) total score >≥ 20
Post-traumatic stress disorder (PTSD) or complex trauma
Psychotic disorder, bipolar disorder, and/or mania
Complex or treatment-resistant obsessive-compulsive disorder (OCD)
Trial design
Treatments tested in this trial
- AI-Digital CBT
- Cognitive Behavioural Therapy