Depression rarely has just one cause. It usually results from a mix of biological, psychological, and environmental factors. Here are five well-supported causes that can contribute to its onset.

1. Genetics and Family History
If close relatives have had depression, your risk increases. Research shows certain genes may affect brain chemistry and stress response, making some people more vulnerable.

2. Brain Chemistry Imbalances
Neurotransmitters like serotonin, dopamine, and norepinephrine help regulate mood. When these chemicals are out of balance—due to illness, stress, or other factors—it can trigger depressive symptoms.

3. Major Life Stressors
Traumatic or stressful events often act as triggers. Examples include losing a loved one, divorce, job loss, financial hardship, or abuse. Chronic stress—like caregiving or loneliness—can also lead to depression over time.

4. Medical Conditions
Certain physical illnesses raise depression risk. These include thyroid disorders, chronic pain, cancer, diabetes, and neurological conditions like Parkinson’s or multiple sclerosis. Inflammation and hormonal changes play a role too.

5. Substance Use and Medications
Alcohol, recreational drugs, and even some prescription medications (like corticosteroids or beta-blockers) can alter brain function and contribute to depression. Substance use may also be a coping mechanism that worsens the condition.

While these factors increase risk, depression can also appear without an obvious cause. That doesn’t make it less real—just more complex.

Understanding the causes of depression helps reduce stigma and guides effective treatment. With the right support, healing is always possible.