Causes and risk factors of depression

Depression is one of the most common mental disorders in the United States. It can affect almost anyone at any age, but it is not always known why some people become depressed.

Researchers suspect that depression actually has many different causes, and they are not always preventable. Factors that may cause depression include:

  • Genetics
  • Brain chemistry
  • Certain medical conditions
  • Substance use
  • pressure
  • Malnutrition

It is estimated that 10% to 15% of the general population will experience clinical depression in their lifetime. The World Health Organization estimates that 5% of men and 9% of women suffer from depression each year.

Brain and body risk factors

There are many different factors that can cause depression, including factors related to the brain and body. Some things that may increase the risk of depression include the following.

Brain chemistry imbalance

One underlying biological cause of depression is the imbalance of neurotransmitters involved in mood regulation.Certain neurotransmitters, including dopamine, serotonin, and norepinephrine, play an important role in mood.

Neurotransmitters are chemicals that help different areas of the brain communicate with each other. When certain neurotransmitters are in short supply, they may cause symptoms that we think are clinical depression.

This theory of depression suggests that too much or too little certain neurotransmitters can cause or at least lead to depression.

Although this explanation is often cited as the main cause of depression, it is still unproven. Many experts believe that it does not paint a complete picture of the complex factors that lead to depression.

Medications for depression usually focus on changing the levels of certain chemicals in the brain. Some of these treatments include selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs), and tricyclic antidepressants (TCAs).

READ ALSO:  Overview of circadian mood changes

Physical health and certain medical conditions

If you have a chronic illness, sleep disorder, or thyroid disease, you may be more likely to have symptoms of depression. People with chronic pain, diabetes, multiple sclerosis, and cancer also tend to have higher rates of depression.

The mind and body are clearly connected. If you experience physical health problems, you may also notice changes in your mental health.

Illness is related to depression in two ways. The stress of chronic illness may trigger major depression. In addition, certain diseases, such as thyroid disease, Addison’s disease, and liver disease, can also cause symptoms of depression.

Female sex hormones

A lot of literature records that women suffer from major depression about twice as often as men. Since the incidence of depression peaks in women’s reproductive years, it is thought that hormonal risk factors may be at work.

Women are particularly susceptible to depression during periods of hormonal instability, such as around menstruation, pregnancy, childbirth, and perimenopause.

Hormonal fluctuations caused by childbirth and thyroid disease can also cause depression. Postpartum depression may occur after a woman has given birth and is believed to be caused by rapid hormonal changes that occur immediately after delivery.

In addition, women have a reduced risk of depression after menopause.

Some common causes of depression

Family history and genetics

Family history of depression is another important risk factor. If your family members also have depression or other types of mood disorders, you are more likely to experience depression symptoms. It is estimated that about 40% of depression is genetically determined.

Twins, adoption, and family studies link depression to genetics. Although studies have shown that there is a strong genetic component, researchers are not yet sure about all the genetic risk factors for depression.

Researchers have found that depression in parents and grandparents doubles the risk of depression.

It is not clear which genes play a role in depression and other mood disorders, but researchers do know that there are many different genes that can play a role. By better understanding their functions, genetic researchers hope to create more effective treatments.

It is important to remember that no single cause of depression is isolated. Genetic factors may be a major risk factor, but scientists also believe that genes and the environment interact to accurately control how these genes are expressed.

Lifestyle risk factors

There are also many lifestyle factors that can cause depression. Although many risk factors for depression (such as your gender or family history) cannot be changed, people have more personal control over lifestyle factors.

Circadian rhythm disorder

A type of depression called seasonal affective disorder (formally known as major depression with a seasonal pattern) is thought to be caused by a disorder of the body’s normal circadian rhythm.

The light entering the eyes affects this rhythm, and in the shorter daylight hours in winter, when people spend limited time outdoors, this rhythm may be disrupted.

People who live in cold climates may face the highest risk, where there are short, dark days.

In addition to the interruption of the circadian rhythm, reduced sunlight can also cause a drop in serotonin levels in the brain, which may affect mood. Seasonal changes also change the level of melatonin in the body, which can disrupt sleep and cause mood changes.

Although you cannot control seasonal changes, there are steps you can take to minimize the impact of these changes on your mental health.


A poor diet can cause depression in many ways. It is known that a lack of multivitamins and minerals can cause depression symptoms.

Some studies have found that a diet low in omega-3 fatty acids or an imbalanced omega-6 to omega-3 ratio can increase the incidence of depression.

In addition, a high-sugar diet is associated with depression.


Stressful life events can overwhelm a person’s ability to cope and may also be the cause of depression.

Researchers suspect that the high levels of the hormone cortisol secreted during periods of stress may affect the neurotransmitter serotonin and cause depression.

Sadness and loss

After losing a loved one, a sad person will experience many of the same symptoms as depression. Difficulty sleeping, loss of appetite, and loss of pleasure or interest in activities are normal responses to loss.

The symptoms of sadness are expected to subside over time. But when symptoms worsen, sadness may turn into depression.

Substance use

Drugs and alcohol can cause depression.However, even some prescription drugs are associated with depression.

Some drugs that have been found to be associated with depression include anticonvulsants, statins, stimulants, benzodiazepines, corticosteroids, and beta blockers.

It is important to check any medications you prescribe, and if you feel depressed, talk to your doctor.

No matter what the reason is, there are effective treatments. If you have symptoms of depression, please consult your doctor in order to develop a treatment plan that suits you.


Causes and risk factors of depression
Scroll to top