What Is The Root Cause Of Depression And How Does It Affect Mental Health?

What are the three leading causes of depression?

There are numerous risk factors that may increase the chances that an individual will develop depression, and researchers still debate the exact cause in any given case. Nevertheless, most agree that alterations in brain chemistry play a significant role. People typically group these risk factors into three broad categories—biological, psychological, and environmental. 

• Biological: With a heritability of approximately 40-50%, depression is thought to have a strong genetic component. A deficiency in neurotransmitters, which are chemicals that communicate messages between nerve cells, is also considered a major biological factor, and any underlying medical condition can amplify this risk. 
• Psychological: Certain personality characteristics, such as high neuroticism, are common psychological contributors. 
• Environmental: Factors may include a physical illness (e.g., COVID-19), stressful events (e.g., the loss of a job), or seasonal changes (e.g., shorter days during winter). 

If you're concerned about these causes, a healthcare provider can make an accurate diagnosis and offer timely support. If you or someone you know is experiencing suicidal thoughts, contact the 988 crisis lifeline right away.

What are the 10 major causes of depression?

Several different causes may lead to the development of depression. Addressing them early can help prevent depression or keep other symptoms from escalating.

Physical and mental disorders that can cause depression

The following is a list of 10 potential contributing factors:

• Brain chemical imbalances (e.g., deficiency in serotonin)
• Grief
• Family history of depression or other mental health conditions
• Comorbid mental disorders (e.g., bipolar disorder)
• Major life events (e.g., moving cities)
• Chronic illnesses (e.g., Alzheimer’s disease, heart disease)
• Other physical health challenges (e.g., chronic pain)
• Personality traits (e.g., neuroticism)
• Ongoing financial problems
• Trauma
• Heavy alcohol use or other substance misuse
• Unexplained weight loss or chronic sleep problems

Recognising and addressing these factors with professional help can prevent depression from worsening.

What is the cause of depression and the most common form of it?

Major depressive disorder (MDD) is the most common form of clinical depression, affecting an estimated 21 million adults in the US in 2021. According to the Diagnostic and Statistical Manual of Mental Disorders, depression symptoms associated with MDD, also known as clinical depression, include low mood, anhedonia, sleep disruptions, psychomotor changes, alterations in eating patterns, and fatigue. These depressive symptoms must persist for at least two weeks to meet the diagnostic criteria. Major depressive disorder is thought to be caused by a mix of environmental, psychological, and biological factors. Examples of environmental factors can include a major life change (e.g., a divorce), a serious medical illness (e.g., mononucleosis), or a chronic illness (e.g., diabetes). Psychological contributors may include personality traits or comorbid mental health conditions, while genetics and brain chemical imbalances are common biological factors. In some cases, individuals may experience mild depression, which still affects daily functioning but may not meet the full criteria for MDD.

Other common depressive disorders include persistent depressive disorder, seasonal affective disorder, and postpartum depression. These conditions, along with clinical depression, are typically treated through psychotherapy, medication, or a combination of both. Therapy can help those who experience depression symptoms talk through their emotions, identify the sources of their feelings, and address any comorbid mental health conditions. Common medications for depression include selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), and monoamine oxidase inhibitors (MAOIs), which aim to regulate brain chemistry. Always consult with a healthcare provider prior to starting or stopping any medication. A doctor may be able to prescribe a more effective medication for you if you experience side effects.

What is the cause of depression among teenagers?

A combination of peer pressure, genetic predisposition, hormonal changes, social pressures, and traumatic life events can cause teens to experience depression. Warning signs include feeling sad or irritable most days for at least two weeks. Early intervention with talk therapy delivered by a mental health professional and strong social support can help prevent depression from worsening. If you notice these patterns, consult a healthcare provider for individualized guidance.

What are the signs of anxiety?

Common signs of anxiety include nervousness, worry, fear, tension, gastrointestinal distress, irritability, fatigue, trouble focusing, and sleep disruptions. You might also have a persistent feeling of unease, unintended weight loss, or other symptoms. When anxiety lasts and you start feeling sad alongside it, speaking with a mental health professional can clarify the next steps.

What is the top cause of depression and its link to heart disease?

Most experts agree that there is not a single cause of depression but several potential contributing factors that can increase the risk of developing the disorder. According to the American Psychiatric Association, these potential causes include alterations in brain structure and function, genetics, personality traits, and environmental contributors. Imbalances in brain chemicals are thought to be a significant factor in the development of depression. Additionally, having a family history of depression or other mental health conditions can increase one’s risk of depression. Personality characteristics such as increased introversion are thought to play a role as well. Lastly, environmental factors—such as a medical illness, chronic pain, stressful life events, or the loss of a loved one—can contribute to the development of the disorder. Furthermore, there is growing evidence that depression and heart disease are closely linked, with each potentially exacerbating the other.

Depression is a complex medical condition with multiple contributing factors. In addition to its emotional and cognitive impact, it can also affect physical health. For example, research suggests that more women with depression may later develop heart disease. Furthermore, alcohol misuse is known to worsen both depression and cardiovascular conditions. Treating depression promptly through therapy, medication, and lifestyle changes may help improve overall well-being and even lead to better cardiac outcomes. In severe cases, unmanaged depression can also lead to self-harm.

How does depression increase the risk of heart disease?

Depression is a chronic medical condition that can sap motivation for exercise, encourage unhealthy habits, and increase inflammation—all pathways that damage cardiovascular health. Building social support and collaborating with cardiac‑informed clinicians can mitigate these effects.

What are the signs of stress linked to causes of depression?

Signs of stress linked to causes of depression include chronic anxiety, irritability, sleep disturbances, and physical symptoms like headaches or stomach aches. Physical problems can also exacerbate depression, creating a cycle of mental and physical symptoms. If these problems persist for several weeks, they can heighten vulnerability to depressive episodes and generate a persistent feeling of being “on edge.”

What happens in the brain during depression?

Research shows that a number of different things happen in the brain when a person experiences a mood disorder such as depression. For example, the brain can become inflamed, which can cause depressive symptoms. There may also be more activity in certain brain regions, like the amygdala, and the hippocampus can shrink over time. 

Having depression treated can restore the brain to some extent. It may be best to seek treatment from a doctor or mental healthcare provider experienced in mood disorders for an accurate diagnosis. They can review your medical history and psychological factors to rule out any other conditions that could be contributing to your mental health symptoms. 

Once you have your depression diagnosed, you’ll want to consider your treatment options. Research suggests a combination of psychotherapy (or talk therapy) and medication could be the best approach. Alternative treatments such as herbal supplements, lifestyle changes, and brain stimulation therapy may also be available. 

What triggers depression and anxiety?

Several factors can trigger depression, anxiety, or both. Some of these include: 

• Physical or sexual abuse
• Traumatic or stressful events
• Certain medications and medical conditions
• Certain personality traits
• Substance misuse
• Having blood relatives with a history of a mental health condition
• Changes in brain chemistry
• Pregnancy (in the case of prenatal depression)

Despite having risk factors compared to the general population, there may be some ways to prevent depression by managing known risk factors and adopting healthy lifestyle changes.

Depression is often associated with physical aches and emotional problems like low self-esteem, but you could have a more severe form that causes intense symptoms. In severe cases, depression causes self-harm, suicidal thoughts, and even suicide attempts. If you’re experiencing these, go to the nearest emergency room and call or text 988 to reach the Suicide & Crisis Lifeline. Remember, depression is a medical condition, and it’s nothing to be ashamed about. If you’re a member of a faith community, you can also reach out to a spiritual leader for guidance and support.