What Are the Causes and Risk Factors of Depression?

Depression is one of the most common mental health conditions in the world right now, and it is becoming more common, not less. In 2025, more than 18% of U.S. adults reported currently having depression or being treated for it. That is nearly 48 million people. If you or someone you love has been struggling, you are not alone, and you are not broken.

But here is something that matters: depression is not a character flaw, a weakness, or something you can just think your way out of. It has real causes. And understanding those causes is often the first step toward getting the right kind of help.

At Stillbrook Counseling in Morgan, Utah, we work with teens and adults across Weber County, Morgan County, and Ogden who are dealing with depression. We also offer telehealth for anyone in Utah who cannot make it in person. One of the most important conversations we have with new clients is this one: where does depression actually come from?

Depression Is Rarely Caused by One Thing

Before we break down the specific causes, it is worth saying this clearly: depression is almost never the result of a single event or a single gene or a single bad decision. Research from Harvard Medical School confirms that depression does not spring from one thing going wrong in the brain. It is far more complex than that. Multiple factors work together, layer on top of each other, and over time create the conditions for depression to develop.

That means blaming yourself for being depressed is not just unhelpful. It is also scientifically inaccurate.

Biological Causes of Depression

Brain Chemistry and Neurotransmitters

You have probably heard that depression is a "chemical imbalance." That is true in part, but it is also an oversimplification. What we know is that imbalances in neurotransmitters like serotonin and dopamine play a role in depression. These are the chemical messengers your brain uses to regulate mood, motivation, sleep, and how you experience pleasure.

When those systems are disrupted, whether from stress, genetics, illness, or other factors, the result can look a lot like depression: low energy, persistent sadness, difficulty concentrating, and a loss of interest in things that used to matter to you.

Genetics and Family History

Depression runs in families, and that is not just a coincidence. Research suggests that genetics account for roughly 40 to 50% of a person's risk for developing depression. If you have a parent or sibling with major depression, your risk is two to three times higher than someone without that family history.

That said, having a family history does not mean depression is inevitable. Many people with genetic risk factors never develop depression. And many people who do develop depression have no family history at all. Genetics loads the gun, as researchers sometimes say, but environment pulls the trigger.

Hormonal Changes

Hormonal shifts can have a significant impact on mood. This is why depression is especially common during pregnancy, after childbirth, during perimenopause, and with thyroid conditions. These are not just "emotional" experiences. They involve real, measurable changes in how the brain and body function together.

Chronic Illness and Physical Health Conditions

People managing long-term health conditions face a significantly higher risk of depression. The connection goes both ways. Chronic physical conditions like cardiovascular disease, diabetes, chronic pain, and neurological diseases increase depression risk. And depression, in turn, can make managing those conditions much harder. People with depression have a 40% higher risk of developing cardiovascular disease, hypertension, stroke, diabetes, or metabolic syndrome compared to the general population.

Psychological and Life Experience Causes

Trauma

Trauma is one of the most well-documented risk factors for depression. This includes childhood abuse, neglect, sexual trauma, combat exposure, accidents, and sudden loss. Research from Harvard shows that early trauma can cause lasting changes in brain function, particularly in the regions that regulate stress and emotional response. Those changes can make a person significantly more vulnerable to depression later in life, especially when new stressors arise.

Grief and Loss

The death of someone you love, the end of a relationship, a major life transition, losing a job, watching a marriage fall apart. Grief is a natural response to loss, but for many people, grief deepens into depression, especially when there is not enough support around them. At Stillbrook Counseling, we see this often, and it is one of the reasons grief counseling is a core part of what we do.

Prolonged Stress

Chronic stress, the kind that does not let up, wears down the brain's ability to regulate mood. Financial pressure, relationship conflict, work stress, caregiving demands, and housing insecurity can all contribute. According to the CDC, adults living below the federal poverty level experience depression at a rate of 22.1%, compared to 7.4% among those with higher incomes. That gap tells a real story about the relationship between stress, circumstances, and mental health.

Negative Thinking Patterns

People who tend toward self-criticism, rumination, or a pessimistic view of the world are at higher risk of depression. This is not about weakness. These patterns often develop as adaptations to difficult experiences. Cognitive Behavioral Therapy (CBT) and other approaches can directly address these patterns, which is part of why therapy is so effective for depression.

Social and Environmental Risk Factors

Isolation and Loneliness

Loneliness is not just uncomfortable. It is a genuine risk factor for depression. Research shows that 33% of lonely adults have depression, compared to 13% of those who do not feel lonely. Social connection is protective, which means isolation works in the opposite direction.

Major Life Changes

Starting college, moving to a new place, divorce, retirement, becoming a parent, losing a job. Even positive changes can destabilize a person's sense of self and routine in ways that leave them vulnerable. When those transitions come with loss or uncertainty, depression risk goes up.

Substance Use

Depression and substance use often go hand in hand. Alcohol and drugs can alter brain chemistry in ways that worsen depression over time, and many people use substances to cope with depressive symptoms before they have ever gotten a diagnosis. About 34.5% of U.S. adults with mental illness also have a substance use disorder.

Who Is Most at Risk?

Depression can affect anyone. But some groups face significantly higher rates:

Young adults between 18 and 29 have the highest rates of depression right now, at 26.7%, more than double the rate from 2017. Women are diagnosed at nearly double the rate of men. LGBTQ+ young people face especially high rates, with 53% of LGBTQ+ teens and young adults reporting recent symptoms of depression. People in lower income brackets experience depression at far higher rates than higher earners.

These disparities are not random. They reflect the real weight that stress, marginalization, economic pressure, and lack of access to care place on mental health.

Depression Is Treatable

Here is what we want you to walk away knowing: depression has real causes, it is not your fault, and it responds well to treatment. Research consistently shows that therapy, including approaches like CBT, ACT, IFS, and trauma-focused modalities, can make a significant difference. In many cases, the combination of therapy and medication is even more effective than either alone.

At Stillbrook Counseling, we offer in-person therapy in Morgan, Utah, serving clients throughout Weber County, Morgan County, and Ogden. We also provide telehealth services to clients anywhere in Utah. We work with teens and adults and use approaches like IFS, ACT, CBT, DBT, and Narrative Therapy to help people move through depression toward something that actually feels like their life again.

We accept Medicare, SelectHealth, Regence BlueCross BlueShield, PEHP, and Optum/UHC. Insurance should not be the reason you do not get help.

If you are ready to talk to someone, we are here.

Stillbrook Counseling is a private practice in Morgan, Utah, offering therapy for depression, anxiety, grief, trauma, and more. Contact us to schedule a free consultation