Depression is one of the most prevalent mental health conditions in the country. Around 23% of Americans who sought mental health treatment in 2023 were diagnosed with it. But what causes depression in the brain? While most people have heard the condition described as a chemical imbalance, the science behind it is a bit more complicated.
What Causes Depression in the Brain?
Depression affects how the brain processes emotions, thoughts and stress. Scientists used to think depression was caused by the brain not producing enough serotonin, dopamine or norepinephrine, the neurotransmitters associated with mood regulation. However, the science behind depression is more complex. The condition isn’t just about neurotransmitter levels. It’s also affected by their interactions with receptors and how the brain uses them.
The brain relies on networks of neurons to process thoughts and emotions. The connections between these networks can weaken when someone’s depressed. Brain regions, such as the hippocampus (associated with emotions and memory), the prefrontal cortex (responsible for decision-making) and the amygdala (linked to fear and emotional responses), may shrink or change how they function in individuals suffering from depression.
Biological Factors Linked to Depression
Genetics and biology also contribute to the onset of depression. A person who has a close relative, such as a parent or sibling, with depression has a higher chance of developing the condition due to shared genetic variations.
Hormones are responsible for various functions, including emotions, energy levels and stress responses. Hormone imbalances, or “sad hormones,” don’t directly cause depression but can influence the brain and emotional well-being.
Hormonal shifts during pregnancy, menopause or menstrual cycles can trigger mood changes. Postpartum depression is a well-known example of how hormone changes can lead to mental health struggles. When experiencing stress, the body releases cortisol. High levels of this hormone can harm the brain if stress is constant. Similarly, an underactive thyroid can cause symptoms of depression due to its role in regulating energy and mood.
Surprisingly, gut heath also influences mood. The gut is home to trillions of bacteria, which play a role in neurotransmitter production. If the balance of gut bacteria is off, it can potentially cause a depressive episode.
People with chronic illnesses, such as diabetes and multiple sclerosis, are at risk due to biological changes and the emotional toll of managing a long-term illness. Diseases including Parkinson’s and Alzheimer’s can alter brain chemistry and lead to depressive symptoms. Inflammation in the brain or body may also play a role in depression as it can obstruct the production of neurotransmitters such as serotonin.
Environmental and Psychological Triggers
External events or internal struggles can trigger depressive episodes. While everyone reacts to life challenges differently, certain environmental and psychological factors can be significant. Triggers can include:
- Grief. Sadness after losing a family member, friend or pet can sometimes deepen into clinical depression.
- Relationship issues. A breakup, divorce or ongoing conflict can create emotional distress that may lead to depression.
- Chronic stress. When stress becomes a constant presence, managing emotions and recovering from challenges can become more difficult.
- Trauma. Adverse childhood experiences, such as neglect or growing up in a chaotic environment, may cause difficulty regulating emotions later in life.
- Isolation. Loneliness and the lack of a support system can create a sense of worthlessness or despair, which can exacerbate depression symptoms.
- Social media. Constant comparison with others online can cause feelings of inferiority or dissatisfaction with life.
- Negativity. Dwelling on negative thoughts or past mistakes can worsen depressive symptoms.
- Burnout. The pressure to achieve certain life goals can lead to exhaustion and feelings of inadequacy.
- Low self-esteem. A person who believes they’re unworthy or incapable can have difficulty recovering from setbacks.
- Life transitions. Even positive changes, such as moving to a new city, can create stress, making adjustment difficult.
How Lifestyle Influences Brain Chemistry
Habits and routines can impact the brain’s chemistry. Over time, lifestyle choices can support or disrupt the brain’s functions.
Poor sleep or inconsistent sleep patterns can lead to imbalances in mood-regulating chemicals such as serotonin and cortisol. A diet high in processed foods can cause inflammation, which may interfere with neurotransmitter production.
Exercise isn’t just good for the body; it’s excellent for the brain, too. Physical activity causes the release of endorphins and serotonin, which may improve mood. Regular exercise can increase neuroplasticity, meaning it helps the brain adapt and form new, healthier neural connections.
Even social life plays a part in brain function. When a person interacts with others, their brain releases oxytocin, a hormone associated with trust and connection. However, becoming isolated has the opposite effect.
Moving Beyond Simplistic Views of Depression
While chemical imbalances may play a role, there’s more to depression than low serotonin levels. This complex condition can’t be dismissed as a momentary sadness. It’s a multifaceted issue. For example, having a family history of depression may increase an individual’s risk of developing the condition, but it doesn’t guarantee they’ll experience it.
Depression itself varies from one person to the next. Some people feel numb and empty. Others feel constant sadness or anxiety. Recognizing these differences contributes to looking for well-rounded solutions. Treatments vary, too. Medications may be helpful, but therapy and support groups also play key roles.
The condition often includes physical symptoms, such as fatigue, changes in appetite and chronic pain. Those living with these symptoms struggle with everyday tasks, which reinforces their own negative thoughts and feelings. As suicidal ideation is common, understanding depression and its nuances is an important aspect of saving the lives of those affected.
A broader perspective on depression can contribute to better treatment options, including holistic therapy approaches. A more complete view of the issue can lead to lasting improvements in mood and quality of life for people diagnosed with this condition.
Finding Joy Beyond Depression
If you’re overwhelmed, you don’t have to face this alone. The dedicated team at Restore Mental Health is on call day and night to help you navigate any challenges you may face. Contact us now; reaching out for help is a sign of strength, not weakness.
