Action Tendencies and Prognosis in Major Depressive Disorder

Inclusion Criteria (MDD group): * Age≥18 * At least moderately severe major depressive syndrome on PHQ-9 (score≥15) at pre-screening despite having tried a serotonergic antidepressant medication * Resident in the UK * Able to complete self-report scales orally or in writing. Inclusion Criteria (Control group) * Age≥18 * PHQ scores \< 10 at pre-screening * Resident in the UK * Able to complete self-report scales orally or in writing Exclusion Criteria (MDD group) * Inability to consent to the study * Unstable medical condition * Currently being treated by mental health specialist * Past diagnosis or family history of schizophrenia or schizo-affective disorder * Current or family history of psychotic symptoms or bipolar disorder. * Drug or alcohol abuse over the last 6 months, suspected central neurological condition (e.g. dementia, stroke) * (planned)Pregnancy * Breastfeeding or within 6 months of giving birth Exclusion Criteria (Control group) * Inability to consent to the study * Past history of MDD * First-degree family history of MDD * Unstable medical condition * Currently being treated by mental health specialist * Past diagnosis or family history of schizophrenia or schizo-affective disorder * Current or family history of psychotic symptoms or bipolar disorder. * Drug or alcohol abuse over the last 6 months * Suspected central neurological condition (e.g. dementia, stroke) * (Planned) pregnancy * Breastfeeding or within 6 months of giving birth