What Causes Depression?

Depressive disorder—also known as depression—is a common mental health condition that affects your thoughts, moods, and behaviors. Depression causes feelings of extreme sadness and hopelessness for two or more weeks, among other behavioral and physical symptoms. Symptoms can limit your ability to function and lower your quality of life.1

There is no singular cause of depression—rather, multiple factors can increase your risk of being depressed. Researchers believe that a combination of genetic, biological, environmental, and psychological factors can cause depression. Depressive disorder affects 1 in 6 people in the U.S.—and knowing the risk factors can help you or a loved one seek the support you may need to manage depression. 

 How To Know if You're Depressed

Is Depression Hereditary? 

Some experts believe that there is a genetic component to depressive disorder—meaning that depression and other mood disorders run in families. If you have a parent or sibling with depression, research shows that you are two to three times more likely to have a depression diagnosis at some point in your life as well.2

Evidence also suggests that certain genes can affect your brain chemistry, making you more prone to experiencing depressive moods. The chemicals in the brain, known as neurotransmitters, allow the nerve cells (neurons) to communicate with each other. When your neurotransmitters aren’t functioning normally, you are at an increased risk of having depression, and other mental health conditions.3

Keep in mind that genetics is not the only risk factor for depression. Having certain genes does not guarantee that you will experience depression—and, people with depression don’t always have a family history of the condition. 

Who Gets Depression? 

Anyone can experience depression and it’s not always possible to see it coming. However, there are some known factors that can raise your risk of developing symptoms. 

Factors that increase your risk of depression include:3

• Younger age: People in their later teenage years and early adulthood are more likely to receive a diagnosis of depressive disorder.
• Assigned female at birth: Depressive disorder is twice as common in women than in men. Changes in the hormone levels of estrogen and progesterone during the menstrual cycle and across the lifespan may increase your risk of developing symptoms.4
• Childbirth: Going through pregnancy and childbirth can raise your risk of depression. Research also suggests that 1 in 8 people experience postpartum depression after giving birth. Experiencing a stressful life event, such as a miscarriage or traumatic birth also increases your risk of depression symptoms.4
• Chronic health conditions: People with chronic (long-term) health conditions like cancer, lupus, thyroid disease, and chronic pain are more likely to experience depression. Additionally, having another mental health condition, such as anxiety, also increases your likelihood of having depressive moods. 
• Central nervous system conditions: People with conditions that affect their central nervous system (e.g., brain and spinal cord)—like stroke, Parkinson’s disease, or a traumatic brain injury—are more likely to also experience depression.
• Substance use: People who use drugs, drink alcohol, or have a pre-existing diagnosis of substance use disorder are at an increased risk of depressive disorder.1

 What Is High-Functioning Depression—And Could You Have It?

Risk Factors 

The primary risk factors for developing depression are stressful life events. It’s not possible to control each of these factors, but knowing the risks is important to keep in mind.5

Major life events are stressful, and this stress can put you at risk of developing depression. Stressful life events may include a variety of environmental and lifestyle changes, such as:1

• Death or loss of a loved one
• Divorce, break-up, or another ending of a relationship 
• Major injury or illness
• Loss of employment (e.g., being fired or laid off)
• Natural disasters (e.g., hurricanes, fires, earthquakes)
• Acts of violence (e.g., mass shootings, abuse, or assault) 
• Financial insecurity or living in poverty 
• Losing your home or having to move unexpectedly 
• Going to a new school or college for the first time
• Being in an accident
• Living through a pandemic
• Systemic issues such as experiencing sexism, racism, misogyny, or homophobia 
• Becoming the primary caretaker for children, aging parents, or sick family members

Sometimes, life events that are seen as positive—such as getting married, buying a house, or getting pregnant—can also cause major stress and increase your risk for depression.

Research shows that people who report having poor social support are more likely to develop depression after going through a stressful time. Therefore, one way to reduce your risk of experiencing depressive moods is to make time to speak to your loved ones, join a support group, or meet with a mental health professional when going through challenges or stress.

A Quick Review 

Depression is a common mental health condition that affects your thoughts, moods, and behaviors. While there is no singular cause of depression, a variety of genetic, demographic, environmental, lifestyle, and psychological factors can increase your risk of developing the condition.

Having a family history, being assigned female at birth, using substances, and undergoing stressful life events are among the most common risk factors for experiencing symptoms. Depression is often difficult to go through—and that’s OK. Knowing the risks can help you or a loved one get the proper support and treatment to manage depression symptoms.