Clinical Research Directory

Inclusion Criteria: 1. Age: Adults aged 18 to 44 years. 2. Residency: Current legal residents of the United States. 3. Clinical Phenotype: Self-report of Major Depressive Disorder (MDD), Generalized Anxiety Disorder (GAD), Post-Traumatic Stress Disorder (PTSD), or Panic Disorder. 4. Medication Stability: If currently prescribed psychotropic medications (e.g., SSRIs, SNRIs, benzodiazepines), the dosage must remain stable with no changes in molecule or quantity for at least 3 months prior to enrollment. 5. Language and Technology: Proficiency in English and access to a smartphone or computer for digital data entry. 6. Financial Commitment: Explicit agreement to the "Citizen Science" model, including payment for discounted testing kits. Kit shipping (both directions) is prepaid by the study. Exclusion Criteria: 1. Use of systemic antibiotics, antifungals, or antivirals within the 8 weeks prior to specimen collection. 2. Regular use of commercial probiotics or concentrated prebiotic supplements within 4 weeks of collection. 3. Frequent use of osmotic or stimulant laxatives, or motility agents, within 4 weeks of collection. 4. Chronic use (\>3 times/week) of NSAIDs, systemic corticosteroids, or high-dose Omega-3 supplementation (\>2g/day) within 4 weeks of enrollment. 5. Use of weight-loss medications or GLP-1 receptor agonists (e.g., semaglutide, liraglutide, tirzepatide) within the 3 months prior to enrollment. 6. Confirmed diagnosis of Irritable Bowel Syndrome (IBS), Inflammatory Bowel Disease (Crohn's or Ulcerative Colitis), Celiac Disease, or history of major gastric/intestinal resection. 7. Current pregnancy or lactation. 8. Presence of cognitive impairments that preclude the ability to provide informed consent. 9. Individuals undergoing active cancer treatment.