AI-Supported Therapy for Depression and Anxiety Compared With Standard CBT

Inclusion Criteria: * 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). * Meet symptom-severity criteria on either validated screening measure: * 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 * If taking psychotropic medication for depression and/or anxiety, be on a stable regimen for at least 6 weeks prior to screening, with no initiation, discontinuation, or dose change during that period. * Have reliable access to a compatible, internet-connected device and are able to use it for screening/eligibility, and the intervention and assessments (any potential costs to participants will be clearly noted in the PIS). * Possess sufficient English language proficiency and cognitive capacity to engage with the digital therapeutic content and complete questionnaires. * Provide informed consent. * Willing to be randomised and to participate in a clinically-supervised CBT-based AI programme, including completion of scheduled outcome assessments. Exclusion Criteria: * Depression: PHQ-9 (or PHQ-A for young persons) total score \>≥ 20 * Present with a primary or comorbid diagnosis (or history of) that is unsuitable for a digital CBT-based intervention (as judged by the Investigator), including: * Post-traumatic stress disorder (PTSD) or complex trauma * Psychotic disorder, bipolar disorder, and/or mania * Complex or treatment-resistant obsessive-compulsive disorder (OCD) * Personality disorder * Eating disorder * Substance or alcohol use disorder * Exhibit high-risk clinical concerns, including: * Current suicidal ideation with intent or plan (as indicated by PHQ-9 score and/or participant disclosure) * Suicide attempt within the past 12 months * Ongoing self-harming behaviours * Requirement for urgent or crisis mental-health intervention (as indicated by •PHQ-9 score and/or participant disclosure) * In participants aged 25 years and under, current treatment with an antidepressant medication initiated or dose-adjusted within the past 12 weeks (due to the recognised