Identifying Cerebral Hemodynamic Patterns in Mood Disorders and Mild Cognitive Impairment: A Functional Near-Infrared Spectroscopy (fNIRS) Study

This study is using a non-invasive brain imaging technique called fNIRS (functional near-infrared spectroscopy) to measure blood flow patterns in the brain of people with major depression, bipolar disorder, or mild cognitive impairment, and compare them to healthy individuals. By identifying unique brain activity patterns in each condition, researchers hope to improve diagnosis, track treatment responses, and better understand what happens in the brain during mood and memory disorders. **You may be eligible if...** - You are 18 years or older - You have a confirmed clinical diagnosis of major depressive disorder, bipolar disorder, or mild cognitive impairment (MCI) - You have stable enough symptoms to safely participate in the study tasks - You are able to provide written consent and understand the study procedures - Healthy adults without mental health diagnoses are also eligible to participate as controls **You may NOT be eligible if...** - You have an active psychiatric crisis requiring immediate treatment - You have a condition (such as severe skin disorders or excessive hair) that prevents accurate fNIRS measurement on the scalp - You are currently experiencing a severe episode that impairs your ability to complete the study tasks - You have significant cognitive impairment that prevents informed consent Talk to your doctor to see if this trial is right for you.