Major Depressive Disorder Diagnosis and Treatment

Learn about the causes, types, signs, symptoms, and treatment methods for major depressive disorder.

Author: J. Flowers Health Staff

What Is Major Depressive Disorder?

Major depressive disorder, also known as clinical depression, is a condition many people experience either personally or adjacently through family or a close friend. Therefore, it is essential to understand what major depressive order entails, its major contributing factors, and how it is treated with the proper medical care and support.

Major depressive disorder is a medical condition characterized by constant hopelessness and despair. It is a widely recognized illness that negatively affects people’s feelings and actions.¹

While it is normal to feel sad and low occasionally, major depressive disorder is persistent and lingers for a long period. The common symptoms include a decreased interest in pleasurable activities, anhedonia, feelings of worthlessness, agitation, and sleep disturbances.

A Deeper Look into Major Depressive Disorder

Symptoms of major depressive disorder range from mild to severe and can include thoughts of death or suicide. This disorder reportedly affects an estimated one in fifteen adults in a year, and one in six people will experience major depressive disorder sometime in their lifetime. On average, it often occurs for the first time during the late teens to mid-20s.¹

In 2008, the World Health Organization (WHO) ranked major depressive disorder as the third-highest cause of disease globally, and it is forecasted that it will rank first by 2030.1 Therefore, it is essential to understand the primary causes of major depressive disorder and the various factors that predispose its development.

Causes of Major Depressive Disorder

There are several causes of major depressive disorder—some are self-inflicted by the affected individual, while others originate genetically. More often, clinical depression can develop from a mixture of both. The causes of major depressive disorder can commonly be attributed to the following:²

Alcohol and Drug Use

Major depressive disorder is linked strongly to alcohol and drug abuse. The abuse of these substances passes as a form of extreme self-medication and has a psychotherapeutic effect on individuals’ brain and general well-being.

Alcohol is a central nervous system depressant, meaning it slows brain function and neural activity and interferes with neurotransmitters responsible for mood regulation. Thus, people who misuse alcohol experience decreased levels of positive, feel-good chemicals in the brain, causing depressive feelings. This is especially dangerous for those who already have depression, as it further inhibits proper brain functioning—creating a vicious cycle.

In addition, the use of drugs acts as a hindrance to the treatment of clinical depression. While drugs can temporarily alleviate the symptoms of severe depressive disorder, consistent use often exacerbates symptoms and leads to a chemical imbalance that generates additional mental health concerns.

Medical Conditions

Some medical conditions, such as cancer and hyperthyroidism, cause major depressive disorder. For example, cancer patients often suffer from persistent periods of low self-esteem and energy towards activities they had previously taken pleasure in. Depression often affects as much as 15% to 25% of cancer patients, usually due to the high-stress levels and emotional impact this disease has on individuals and their loved ones.³

Hyperthyroidism often shares overlapping symptoms with major depressive disorder. People with hyperthyroidism exhibit low appetite, tiredness, poor concentration, sleep disturbance, impaired memory, and irritability. Therefore, a high prevalence of major depressive disorder has been identified in hyperthyroid patients.

Medications

Some medications are closely linked to depression symptoms. For example, beta-blockers treat high blood pressure but are associated with depression symptoms like fatigue and sexual problems. Other drugs, such as benzodiazepines, corticosteroids, H2 blockers, proton pump inhibitors, and drugs used to treat Parkinson’s disease, have also been linked to depression.

Abuse During Childhood

Mistreatment and prolonged periods of abuse during childhood have been identified as a risk for developing lifetime major depressive disorder. The disorder usually develops in adults who underwent childhood neglect and abuse.

Cases of clinical depression are often associated with symptoms such as low physical functioning, adverse mental health, and poor general health. Research has also suggested links between childhood abuse and alterations in brain structure and functions, which have grim consequences.

Types of Depression

Here are the different types of major depressive disorder:

Psychotic Depression

This kind of major depressive disorder occurs when a patient experiences some form of psychosis. Psychosis often manifests itself in the form of hallucinations and delusions. Hallucinations are characterized by hearing imaginary voices that denigrate patients, while delusions involve intense feelings of worthlessness and imaginary guilt.

Melancholic Depression

Melancholic depression is characterized by persistent feelings of sadness and hopelessness that affect all areas of an individual’s life—usually causing a loss of interest in activities.

Catatonic Depression

This type of depressive disorder entails non-communication between an affected individual and others, and the individual seems to be in a daze for prolonged periods. Individuals suffering from catatonic depression do not respond to happenings around them and may appear silent and motionless.

Signs and Symptoms of Depressive Disorder

Knowing how to spot symptoms of major depressive disorder can help affected individuals and prevent grave consequences that stem from untreated depression. Signs of major depressive disorder include:⁴

Anxiety and Agitation

Clinical depression commonly causes severe anxiety and agitation. Agitation triggered by depression frequently leads to angry outbursts and disruptive and impulsive behavior.

Negative Thinking

Another sign of major depressive disorder is a perpetual state of negative thoughts. These thoughts cause consistent pessimistic feelings that can lead to various problematic behaviors.

Inability to Focus

Major depressive disorder can make it difficult to focus on tasks and activities, causing patients to feel disassociated from the present and their environments. Additionally, depression often interferes with motivation to achieve a goal, hence decreased levels of concentration and focus.

Exhaustion and Lethargy

Another common sign is feelings of lethargy and fatigue. People exhibiting clinical depression symptoms frequently display continuous lethargy with no primary underlying cause.

Treatment of Major Depressive Disorder

Major depressive disorder can be treated using various methods designed to alleviate its symptoms:⁵

Medication

Medication is an effective treatment option for depression. The following are the most common and helpful classes and types of medication:

Selective Serotonin Reuptake Inhibitors (SSRIs)

SSRIs are a popular anti-depressant widely used to treat major depressive disorder and often employed in tandem with cognitive behavioral therapy (CBT). This medication poses fewer side effects than other types of antidepressants.

Tricyclic Antidepressants

This is another type of antidepressant prescribed to alleviate major depressive disorder symptoms; however, while this medication exhibits similar levels of efficacy with SSRIs, it poses more adverse side effects. Examples include amitriptyline, amoxapine, and trimipramine.

Monoamine Oxidase Inhibitors

Monoamine oxidase inhibitors, a class of antidepressants, affect the neurotransmitters in the brain by enabling them to communicate better while inhibiting monoamine oxidase, elevating mood in the process.

Serotonin Modulators

This medication targets serotonin neurotransmitters. They control serotonin receptors and inhibit serotonin uptake.

Therapies

Alongside medication, therapy can be beneficial in reducing clinical depression symptoms. The most commonly used therapies include:

Cognitive Behavioral Therapy

Cognitive behavioral therapy (CBT) is a form of psychological treatment proven effective in treating mental health illnesses, including depressive disorder. It involves strategies that help correct a patient’s thinking patterns to instigate change.

Interpersonal Therapy

Interpersonal therapy can be used for mild depression disorders, as it addresses interpersonal issues and relationships. This therapy is proven to be as effective in short-term treatments as antidepressants.

Final Thoughts

Major depressive disorder affects people from all walks of life. Therefore, it is essential to understand the key factors associated with this disorder, such as the causes, signs, symptoms, and methods used to treat it.

Cases of major depressive disorder are forecasted to become widespread in the future. Together we can overcome and prevent clinical depression by gaining a deep understanding of it.⁶