Brain training in a 'high-altitude' room may boost memory in depression

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria (substudy 1): * 18-50 years * No psychiatric history * Fluency in Danish Inclusion Criteria (substudy 2): * 18-65 years * International Classification of Diseases (ICD)-10 diagnosis of Bipolar Disorder or depression confirmed with the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) * Fluency in Danish * Partial or full remission (defined as a score of ≤14 on the Hamilton Depression Rating Scale 17-items (HDRS-17) and the Young Mania Rating Scale (YMRS) * Objectively-verified cognitive impairment according to Screen for Cognitive Impairment in Psychiatry (SCIP) and/or self-reported cognitive impairment measured with Cognitive Complaints in Bipolar disorder Rating Assessment (COBRA). For SCIP, their performance must be ≥0.5 standard deviations (SD) below their demographically adjusted expected total SCIP score or on minimum 2 SCIP subtest scores. For COBRA, patients must report substantial cognitive impairment defined as a score ≥14. Common Exclusion Criteria: * Schizophrenia or schizoaffective disorder * Neurological disorder * Alcohol or substance abuse * History of serious head trauma * Previous altitude sickness * Heart disease * Diabetes * Renal failure * Untreated/insufficiently treated hypertension * Thromboses or thromboembolic events * First-degree family with thromboembolic events before age 60 * Pregnancy * Breastfeeding * Smoking or use other nicotine products regularly * BMI\>30 * Electroconvulsive therapy (ECT) 3 months prior to participation * Dyslexia * Claustrophobia (MRI scans) * Pacemaker and/or other MRI incompatible metal implants (MRI scans) * Participation in experiments with radioactivity (\>10 mSv) within the last year (PET scans) * Significant occupational exposure to radioactivity (PET scans) * Medication incompatible with study aims (e.g., SV2A binding agents; PET scans)