What is major depressive disorder? Symptoms, causes, and treatment

Living with a constant, persistent feeling of sadness, exhaustion, and in a state of despair can weigh heavily on anyone. Like being trapped in a deep, dark hole without a ladder to climb out of, we are left feeling alone, hopeless, and overwhelmed.

This experience is commonly known as major depressive disorder (MDD). The experience of MDD can certainly differ from person to person, yet common threads of intense sadness and disconnection often emerge.

If you’ve been feeling any of these symptoms, you are not alone.

MDD is a significant, yet somewhat under-discussed mental health condition. We are here to shed more light on the symptoms, causes, and treatment to raise awareness, foster understanding, and provide support for those affected.

What is major depressive disorder?

Major depressive disorder, sometimes referred to as clinical depression, is a serious mental illness characterized by episodes of persistent sadness, loss of interest in activities, fatigue, feelings of guilt or worthlessness, and a myriad of other symptoms.

MDD is the most common type of depression affecting 21 million adults across the United States, with prevalence rates almost twice as high in women compared to men.

MDD is different from other mood disorders, and symptoms in each diagnosis can be different. Perhaps the most impactful aspect of MDD is that it disrupts the essential aspects of our day-to-day lives. This includes making it difficult to want to engage in activities that once brought us joy, maintain relationships that matter to us, and even perform basic chores around the house.

With MDD affecting children as young as 12 years old, early detection and treatment is a top priority.

Signs and symptoms of major depressive disorder

During a depressive episode, individuals experience a range of symptoms affecting their mind, body, emotions, and behavior.

According to the current Diagnostic and Statistical Manual of Mental Disorders (DSM-5), to qualify for a diagnosis of major depression, there must be at least five or more of the following symptoms present:

• Depressed mood (persistent sadness or low mood)

• Loss of interest in nearly all activities

• Significant (5% or more per month) and unintentional loss or gain of weight or decrease/increase in appetite

• Disrupted sleep patterns (insomnia or hypersomnia)

• Significant changes in movement patterns (faster or slower)

• Tiredness, fatigue, or low energy

• Feelings of hopelessness, worthlessness, or delusional guilt

• Difficulty concentrating or making decisions

• Suicidal ideations or attempts

It is important to note that individuals suffering from major depression may experience episodes with varying degrees of severity.

Suicidal thoughts or behaviors: warning signs

Recognizing suicidal thoughts or behaviors in ourselves and others is crucial for safety, intervention, and seeking support.

The World Health Organization (WHO) identifies several strategies to consider if you are struggling with thoughts of suicide.

These include:

• Remembering that you’re not alone, and other individuals who have experienced these symptoms have received treatment and support and gotten better

• Opening up to a friend, family member or professional to discuss your symptoms is helpful in reducing feelings of isolation

• Considering joining a support group to receive resources and support

If you or someone you know is in danger of harming yourself/themself, contact emergency services or a crisis line for immediate support.

Causes of major depressive disorder

While there is no one ‘root cause’ of major depression, there are several factors that come into play to contribute to its onset and development.

Biological factors

MDD has a strong link to our biology.

Based on current research, here is what we know:

1. Individuals with major depression often have high levels of cortisol in their blood, demonstrating over-activation of the hypothalamic-pituitary-adrenal (HPA) axis causing an increased stress response and altered mood and emotional state

2. MDD exhibits dysregulated neurotransmitter levels (i.e. serotonin, dopamine, and norepinephrine) contributing to altered mood, emotions, and cognitive functioning

3. Major depression shows a strong familial and genetic link, with relatives of affected individuals at a higher risk of developing the disorder

As a result of these biological factors linked to major depression, individuals experience a complex interplay of mood changes, emotional turbulence, and cognitive challenges.

Psychological factors

On the psychological side, many factors can both contribute to and worsen symptoms of major depression.

Low self-esteem or issues related to our self-perception can cause us to withdraw from social settings, avoid new experiences, and shy away from challenges that could help us grow. Low self-esteem can impact our mental health and even lead to more serious issues including depression and anxiety disorders.

Similarly, certain cognitive patterns, such as negative self-talk, can perpetuate feelings of worthlessness and hopelessness and worsen depressive symptoms. This 2021 study found negative self-talk can change our brain states, affecting our confidence, cognitive performance, and levels of motivation.

Environmental factors

Our environment plays a prominent role in our health. Individuals experiencing adverse life events or unexpected stressors, such as divorcing a spouse, losing a loved one, or facing a trauma event are more likely to develop depression later in life.

Other contributing environmental factors include:

• Lack of physical activity

• Harmful use of alcohol or other substances

• Poor diet (quality and quantity)

• Past emotional, physical, or sexual trauma

• Stressful living conditions (i.e. high crime locations or incidences of environmental disasters)

These factors can vary in their impact from person to person, and often, multiple factors may contribute to the development or exacerbation of depressive symptoms.

Interplay of multiple factors

Most often, these factors interact and amplify their collective effect on our well-being.

According to a 2015 NIH study, MDD is a “multifactorial and polygenic disorder,” meaning that it is likely that multiple factors overlap to contribute to the development and exacerbation of depression.

For instance, having the genes for MDD along with living in certain stressful conditions can act cumulatively throughout our lifetime, creating the ‘perfect storm’ for depression.

Diagnosis of major depressive disorder

The path to diagnosing major depression can look a little different for everyone. However, the common process involves a clinical assessment involving history taking and assessment tools.

Clinical assessment

According to the DSM-5, a formal diagnosis of major depression requires individuals to experience episodes that vary in duration, typically lasting for at least two weeks.

These episodes require at least five symptoms described earlier, causing significant distress or impairment in social, occupational, or other important areas of functioning.

Receiving a comprehensive clinical assessment is central to the diagnosis process. This is often performed by a psychiatrist or other licensed mental health professional, which includes:

• Performing a clinical interview: collecting a patient’s medical history, family history, social history, substance use history, and current symptoms

• Assessing physical and neurological functioning: evaluating medical conditions or neurological factors that may contribute to depressive symptoms

Physicians may also interview family members, caregivers, or friends to gain a complete understanding of a patient’s current levels of functioning and support networks.

Assessment tools

The use of self-assessment and clinician-administered tools and rating scales helps determine both the type and severity of depression. Common tools include:

• Patient Health Questionnaire-9 (PHQ-9): Takes a look at depression severity based on DSM-5 criteria with scores ranging from 0 to 27 (≥10 possible indication of MDD)

• Hamilton Rating Scale for Depression (HAM-D): A scale which includes 17 items used to assess symptoms severity (i.e. mood, feelings of guilt, sleep disturbances, and anxiety symptoms)

• Montgomery-Asberg Depression Rating Scale (MADRS): Focuses on depressive symptom severity

• Beck Depression Inventory (BDI): Assesses symptoms severity based on levels of sadness, guilt, irritability, etc.

• Zung Self-Rating Depression Scale: Measures psychological, affective, and somatic symptoms associated with depression

• Raskin Depression Rating Scale: Evaluates the severity of depression symptoms, including mood, pessimism, sense of failure, and suicidal ideations

While some tools overlap in their design, each provides valuable insight into MDD symptomatology to allow for more efficient and effective diagnosis and treatment planning.

Role of healthcare providers

Healthcare providers play a distinct role in diagnosing major depression.

Primary care physicians are often the first point of contact for individuals experiencing depressive symptoms. They conduct initial assessments, including physical exams and medical history interviews to rule out certain conditions.

Psychiatrists are specialists in diagnosing and treating a range of mental health disorders, including MDD. They conduct a more comprehensive psychiatric assessment, using tools to assess symptom severity. Psychiatrists can also prescribe medications, which serve as pharmacological treatments.

Similar to psychiatrists, clinical psychologists or licensed therapists are also qualified to make a formal diagnosis of MDD in the U.S. These specialists focus on providing psychotherapy to clients to help them cope with and recover from their symptoms.

Treatment options for major depressive disorder

There are several standardized treatment options in which individuals can discover relief from their distress. Here are some of the most effective treatments for MDD.

Psychotherapy

With depression, the intention is to raise individuals’ level of motivation and arousal to engage in areas of life that previously brought joy. This can be accomplished using several therapeutic modalities tailored for depressive symptom reduction.

Cognitive behavioral therapy

Cognitive behavioral therapy (CBT) is a form of behavioral therapy that focuses on identifying and changing negative thought patterns and behaviors that contribute to depression.

Common techniques used in CBT treatment include:

• Cognitive restructuring which works to retrain the brain, minimize negative self-talk, and boost self-esteem

• Behavioral activation empowers individuals by increasing engagement in positive activities to improve mood and levels of motivation

• Skills training works by teaching strategies to cope with the challenges caused by symptoms of depression

Similar to other forms of behavioral therapy, CBT works to help you manage and cope with symptoms of MDD more effectively, giving you back the strength to take control of your life.

Interpersonal therapy 

Interpersonal Therapy IPT is a form of relational therapy that focuses on improving interpersonal relationships and social functioning.

It helps individuals cope with symptoms of depression by addressing issues such as unresolved grief, challenging role transitions, and interpersonal conflicts, thereby enhancing communication skills and relationship patterns.

Psychodynamic therapy

Psychodynamic therapy is a humanistic approach that takes into account the influence of early experiences and unconscious processes on current behavior.

It is useful in treating depression as it helps individuals gain insight into unresolved conflicts and emotional patterns, fostering deeper self-understanding and healing.

Medication

Antidepressants are a highly validated treatment option for major depression. Selective serotonin reuptake inhibitors (SSRIs) are frequent options for the treatment of depression.

Other common psychotherapy options include serotonin-norepinephrine reuptake inhibitors (SNRIs) and tricyclics.

That being said, there are certain side effects to consider with any medication, which is why it’s key that you discuss medication options at length with your qualified provider before making decisions.

Lifestyle modifications

Like many other forms of depression—such as persistent depressive disorder, postpartum depression, and even seasonal affective disorder—the symptom severity of major depression can be modified with several lifestyle changes.

Regular physical activity is shown to be highly beneficial for individuals suffering from MDD as a way to boost mood, increase energy, increase levels of feel-good endorphins, such as serotonin, and lead to more favorable outcomes.

Similarly, diet can also significantly impact our mental health. Harvard Health encourages a balanced diet rich in colorful fruits and vegetables, whole grains, and lean proteins to improve brain function and regulate mood.

Lastly, maintaining good sleep hygiene is a central way to improve mental wellness. Research notes that sleep duration is an important aspect, as too much and too little can both increase the risk of depression.

Alternative approaches

Beyond the more traditional avenues for MDD treatment, researchers have also considered several alternative options that have shown promise in alleviating symptoms and improving overall well-being.

These include:

• Esketamine: This form of antidepressant is a fast-acting FDA-approved nasal spray that helps to quickly enter the system and relieve distressing symptoms of depression

• Dextromethorphan-bupropion: This combination medication is another FDA-approved option to reduce depression symptoms within 1-2 weeks

• Transcranial Magnetic Stimulation (TMS): This non-medication treatment uses magnetic fields to stimulate nerve cells in the brain to alleviate depression symptoms and increase remission rates

• Electroconvulsive Therapy (ECT): ECT is a relatively safe method to help individuals struggling with treatment-resistant depression

These innovative approaches offer new ways to manage depression, giving individuals hope for their future.

Ways therapy can help with major depression

Therapy is an effective treatment that has been proven to alleviate the suffering caused by depressive episodes, and help those individuals who experience depression get back on track with their social lives, relationships, careers, and schooling endeavors.

Psychotherapeutic interventions can help with:

• Emotional support and validation: Therapy offers a safe and non-judgmental space for individuals to explore their feelings, concerns, and hardships

• Developing coping strategies: Techniques are tailored to individuals in a way to help manage specific symptoms of MDD, overcome stress, and create more adaptive ways of thinking and behaving

• Addressing underlying issues: Therapy holds space to explore root causes of depression, including patterns of thinking or behaving and past traumas or experiences to foster insight and promote emotional healing

• Boosting self-esteem and self-efficacy: Teaching skills to build confidence that empowers individuals to navigate challenges, pursue goals, and create a positive sense of self-worth

• Preventing relapse: Maintenance therapy and follow-up care are provided to individuals to prevent the recurrence of symptoms and support sustained progress toward long-term recovery and well-being

Therapy is meant to offer a pathway to understanding and managing one’s emotions and behaviors.

Finding support

Have you been considering reaching out for support? Consider Grow Therapy.