Last updated date: 28-Feb-2023

Originally Written in English

Major depressive disorders (clinical depression) - types, symptoms, causes, and treatment

  • General Health

Depression differs from normal mood fluctuations and short-term emotional responses to everyday challenges. However, lasting with moderate to severe severity, depression can become a serious health condition. It can cause those affected to suffer greatly and perform poorly at work, at school and in their families. At worst, depression can lead to suicide.

Depression is a common illness worldwide, affecting more than 264 million people. Major depressive disorder is one of the most common forms of schizophrenia, affecting approximately one in six of the men and one in four women in their lives.

Major depressive disorder (MDD) is a severe condition characterized by low mood, lowered interests, poor cognitive function, and vegetative symptoms such as disordered sleep or eating. MDD affects one in every six adults in their lifetime and affects about twice as many women as men. 


Major depressive disorder symptoms

Symptoms of major depressive disorder (MDD) may include:

  • feeling depressed almost every day
  • loss of interest in activities you once enjoyed
  • changes in appetite or weight were found
  • have trouble sleeping
  • feeling lazy or restless
  • low energy
  • feeling hopeless or worthless
  • have trouble concentrating
  • have frequent thoughts about death or suicide


Depression relapses:

It is also highly recurrent, with at least 50% of people recovering from the first episode of depression having at least one additional episode in their lives, and about 80% of people having a history of two episodes. There is a recurrence

When the first episode occurs, the episodes usually begin within five years of the first episode and, on average, a person with a history of depression will have five to nine depressive episodes in their lifetime.


Symptoms of Depression Relapse:

  • difficulty concentrating
  • disturbed sleep
  • reduces sensitive energy levels
  • persistent mild anxiety


Major depression in adults:

Depression is a common adult disorder that often leads to poor quality of life and impaired role functioning. Depression is also associated with high rates of suicidal behavior and death. When depression occurs in the context of a medical illness, it is associated with increased health care costs, longer hospitalization periods, poor cooperation in treating compliance, and more. Poor treatment and high morbidity rates.

Causes of depression in adults can be linked to the difficulty of changing roles:

  • Low education and low income
  • Teen Tall Child-Bearing
  • Interruption of marriage
  • Unstable employment and
  • Highly competitive and stressful work


The main symptoms of depression in adults include:

  • Mostly sad or depressed
  • Loss of interest or pleasure and avoiding social gatherings
  • Decreased energy and fatigue
  • Decreased concentration and attention
  • Decreased self-esteem and self-confidence
  • Thoughts of guilt and unworthiness
  • A bleak and pessimistic view of the future
  • Thoughts or actions of self-harm or suicidal thoughts
  • Disturbed sleep or insomnia
  • Marked and diminished appetite


Major depressive disorder criteria DSM-5

depressive disorder criteria DSM-5

According to the DSM-5, the following criteria must be satisfied in order to make a diagnosis of major depression:

At least five of the following symptoms must be present for at least two weeks and reflect a change from previous functionality. Furthermore, at least one of the symptoms is a low mood or a loss of interest or pleasure.

  • The individual is depressed for most of the day, almost every day, as noticed by themselves or others.
  • He or she is disinterested in all or most activities for most of the day, nearly every day.
  • Every day, the individual gains or loses a large amount of weight or has a decreased or increased appetite.
  • Almost every day, he or she suffers from insomnia or hypersomnia.
  • Every day, I have a psychomotor impediment that is visible to others as well as self-reported.
  • Almost every day, he or she feels exhausted or tired.
  • Almost every day, the individual has thoughts of worthlessness or extreme guilt.
  • Every day, an individual's capacity to think, focus, or make judgments deteriorates.
  • He or she has recurring thoughts of suicide, suicidal ideation (without a particular plan), a suicide attempt, or a definite plan for committing suicide.
  • The symptoms listed above produce clinically substantial distress or hinder daily function.
  • The depressed episode is not due to the physiological effects of a drug or another medical condition.
  • The episode's occurrence is not better explained by a specific or undefined schizophrenia spectrum illness or other psychotic disorders.
  • The person has never experienced a manic or hypomanic episode.

The diagnostic code for major depressive disorder is based on the frequency of recurrent episodes, the severity of the episodes, the existence of psychotic characteristics, and the state of remission. The following are the codes:



  • Mild
  • Moderate
  • Severe
  • With Psychotic Features
  • In Partial Remission
  • In Full Remission
  • Unspecified


Major depressive illness is a common mental condition. It has a lifetime prevalence ranging from 5 to 17 percent, with an average of 12 percent. The prevalence rate in women is about double that of males. This disparity has been attributed to hormonal variations, the consequences of childbearing, differing psychological pressures in men and women, and a behavioral model of learned helplessness. Despite the fact that the average age of onset is about 40 years, new studies reveal an increase in incidence in the younger population due to the use of alcohol and other substances of abuse.

MDD is more frequent in those who are divorced, separated, or bereaved who do not have meaningful interpersonal interactions. There is no difference in the prevalence of MDD between races or socioeconomic positions. Individuals suffering from MDD frequently have co-occurring illnesses such as substance abuse, panic disorder, social anxiety disorder, and obsessive-compulsive disorder.

The existence of these comorbid diseases in people with MDD raises their risk of suicide. Depression is more common in older persons who have concomitant medical problems. Depression is more common in rural settings than in urban areas.


Major depressive disorder pathophysiology

The genesis of Major Depressive Disorder is thought to be multifaceted, with biological, genetic, environmental, and psychological variables all playing a role. MDD was formerly thought to be caused mostly by anomalies in neurotransmitters, particularly serotonin, norepinephrine, and dopamine.

This has been demonstrated by the use of several antidepressants in the treatment of depression, such as selective serotonin receptor inhibitors, serotonin-norepinephrine receptor inhibitors, and dopamine-norepinephrine receptor inhibitors. Serotonin metabolites were found to be decreased in people who had suicidal thoughts. Recent hypotheses, however, suggest that it is related largely to more sophisticated neuroregulatory systems and brain circuits, resulting in subsequent disruptions of neurotransmitter systems. 

GABA, an inhibitory neurotransmitter, as well as glutamate and glycine, both significant excitatory neurotransmitters, have been identified to have a role in the genesis of depression. Depressed people had reduced GABA levels in their plasma, CSF, and brain. GABA is thought to work as an antidepressant by blocking ascending monoamine pathways, including the mesocortical and mesolimbic systems.

Antidepressant characteristics of drugs that oppose NMDA receptors have been investigated. Thyroid and growth hormone imbalances have also been linked to the genesis of mood disorders. Multiple adversities and trauma in childhood have been linked to the development of depression later in life.

Severe early stress can produce dramatic changes in neuroendocrine and behavioral responses, leading to anatomical abnormalities in the cerebral cortex and severe depression later in life. Structural and functional brain imaging of depressed people revealed greater hyperintensities in subcortical areas and decreased anterior brain metabolism on the left side.

Family, adoption and twin studies have all found that genes have a role in depression risk. Twins with MDD have a very high concordance rate, according to genetic research, especially monozygotic twins. Life experiences and personality qualities have also been found to play an influence.

According to the learned helplessness theory, the onset of depression is linked to the experience of uncontrolled occurrences. Depression, according to cognitive theory, emerges as a result of cognitive errors in those who are predisposed to depression.


Somatic illnesses associated with depression

Somatic sensations are particularly frequent in depression and other mental illnesses. Although somatic symptoms are common in depressed individuals, they have far less weight than core depressive symptoms in the diagnosis of depression.

Clinical stages of sad mood are characterized by both painful and nonpainful bodily symptoms. 


Diagnosis of major depressive disorder

Major depressive disorder is a clinical diagnosis; it is mostly determined by the patient's clinical history and a mental state evaluation. Along with the symptomatology, the clinical interview must include a medical history, family history, social history, and drug use history. Collateral information from a patient's family/friends is a critical component of psychiatric examination.

Although there is no objective testing available to diagnose depression, routine laboratory work such as complete blood count with differential, comprehensive metabolic panel, thyroid-stimulating hormone, free T4, vitamin D, urinalysis, and toxicology screening is performed to rule out organic or medical causes of depression.

Individuals suffering from depression frequently present to their primary care physicians for somatic issues related to their depression, rather than seeking a mental health expert. In almost half of the instances, patients deny experiencing depressive symptoms, and they are frequently referred to therapy by family members or sent by employers to be tested for social withdrawal and decreased activity. At each appointment, it is critical to assess a patient for suicidal or homicidal thoughts.


Take a self-test for depression

Having a bad mood or feeling tense are regular occurrences for all of us. When these feelings persist, you may be suffering from depression or anxiety — or both. These self-tests contain pertinent questions that will help you assess your current situation and devise a strategy for feeling better sooner.

When you're going through a difficult moment, it's natural to feel depressed for a while; feelings like melancholy and loss assist to define who we are. However, if you feel sad or unpleasant most of the time for an extended length of time, you may be suffering from depression.

Take this self-test to see if you're exhibiting any of the warning symptoms of depression. This will not provide you with a diagnosis, but it will help you determine what to do next.


Major depressive disorder with psychotic features

Psychotic depression, also known as a major depressive disorder with psychotic elements, is a serious medical or mental health illness that needs rapid treatment and constant monitoring by a medical or mental health specialist.

Major depressive illness is a prevalent mental condition that can have a detrimental impact on many aspects of a person's life. It has an effect on mood and behavior, as well as different bodily processes such as eating and sleep. People suffering from serious depression frequently lose interest in things they formerly loved and have difficulty doing daily tasks. They may even feel as if life isn't worth living at times.


Bipolar disorder (BD)

Depression in patients with bipolar disorder (BD) presents a significant clinical challenge. As schizophrenia is dominant even in treated BD, depression is associated not only with schizophrenia, but also with excess BD sickness and co-occurring medical disorders with a high suicide risk.


Bipolar Disorder (BD) Diagnosis and Risk Factors:

In perhaps 12-17% of cases, Bipolar Disorder is not recognized until the mood "transforms" to hypomania or mania, either spontaneous or exposed to mood-elevating substances.


Factors that suggest a diagnosis of BD 

  • Familial mania, psychosis, "nervous breakdown" or psychiatric hospitalization
  • Early-onset of illness, often with symptoms of depression
  • Cyclothymic mood
  • Multiple recurrences (eg 4 episodes of depression within 10 years)
  • Depression with distinctive agitation, anger, insomnia, irritability, talkative
  • Other features are "mixed" or hypomanic, or psychotic symptoms
  • Clinically "worsening" especially with mixed properties during antidepressant treatment
  • Suicidal thoughts and actions
  • Substance abuse


Major depressive disorders in children and adolescents:

depressive disorders in children

Major depressive disorder (MDD) can have a significant impact on onset in childhood and adolescence. Impaired school performance, interpersonal problems later in life, early parenthood, and an increased risk of other mental health disorders and substance use disorders have been associated with. Diagnosing MDD in childhood is tricky. MDD children are often underdiagnosed and undertreated with only 50% of adolescents diagnosed before reaching adulthood.

Symptoms of depression in children ages 3-8 include:

  • They have reasonable complaints.
  • Found to be more irritable
  • Show fewer signs of depression
  • Presented with concern
  • Observable behavioral changes

Once a child becomes a teenager and an adult, symptom presentation is consistent with the Diagnostic and Statistical Manual for Mental Disorders (DSM-5) criteria:

  1. Irritability in children or adolescents.
  2. In children, take into account the expected weight gain.
  3. Objectified by others, cannot be limited to a feeling of slowing down or inner restlessness.
  4. Can go as far as delirium and not limited to the guilt of being sick.


Postpartum depression

Postpartum depression affects one out of every seven women (PPD). While most women recover quickly from the baby blues, PPD lasts far longer and has a significant impact on women's capacity to return to regular function.

PPD has an impact on the mother and her bond with her child. PPD impairs maternal brain reaction and behavior. Postpartum depression is most frequent within 6 weeks of delivery. PPD affects from 6.5 percent to 20% of women. It is more frequent in adolescent girls, moms who had preterm newborns, and women who live in cities.

According to one study, African American and Hispanic moms reported the beginning of symptoms within 2 weeks of birth, but white mothers reported the onset of symptoms later.


Premenstrual dysphoric disorder

Premenstrual symptoms are a group of psychological, behavioral, and physical symptoms that occur in a cyclical pattern prior to menstruation and subsequently subside after the menstrual period in women of reproductive age. The majority of females have relatively slight pain, and symptoms do not interfere with their personal, social, or professional lives; nevertheless, 5% to 8% of women experience moderate-to-severe symptoms, which can cause considerable suffering and functional impairment.

All women of reproductive age, from menarche to menopause, might have premenstrual symptoms. Premenstrual symptoms are a typical issue for women of reproductive age. In the United States, around 70 percent to 90 percent of women of reproductive age report at least some premenstrual pain.

Approximately one-third of these women exhibit symptoms severe enough to warrant a diagnosis of PMS. PMDD, the most severe type of premenstrual symptom complex, has been observed in 3% to 8% of these women.


Major depressive disorder treatments


Treatment of major depressive disorder (MDD) in adults:

Treatment options for the major depressive disorder include pharmaceutical, psychological, interventional, and lifestyle change. Medication or/and psychotherapy are used to treat MDD in the beginning.

Combination treatment, which includes both drugs and psychotherapy, has been shown to be more beneficial than either treatment alone. Electroconvulsive therapy has been shown to be more effective than any other treatment for severe major depression.


Psychotherapy of the patient:

Depression education and treatment can be provided to all patients. When appropriate, education can be given to relevant family members.

Education about available treatment options will help patients make informed decisions, anticipate side effects, and follow their prescribed treatment. Another important aspect of the education was to inform patients and concerned family members about the delayed duration of the onset of the antidepressant action.


Pharmacotherapy and acute treatment:

Antidepressants may be used as the primary treatment modality for patients with moderate or severe depression.

Clinical features that may suggest the drug is the preferred therapeutic modality include a history of prior positive response to antidepressants, the severity of symptoms, significant sleep disturbances, and appetite disturbances. agitation or expectation of the need for maintenance.

Patients with severe depression with psychotic features will require antidepressant and antipsychotic and/or electroconvulsive therapy (ECT).

All antidepressants are effective, although their side-effect profiles differ. The following drugs have been approved by the FDA for the treatment of MDD:

  • Fluoxetine, sertraline, citalopram, escitalopram, paroxetine, and fluvoxamine are examples of selective serotonin reuptake inhibitors (SSRIs). They are typically used as the first line of therapy and are the most commonly prescribed antidepressants.
  • Venlafaxine, duloxetine, desvenlafaxine, levomilnacipran, and milnacipran are examples of serotonin-norepinephrine reuptake inhibitors (SNRIs). They are frequently used to treat depressed people who also have pain issues.
  • Trazodone, vilazodone, and vortioxetine are serotonin modulators.
  • Bupropion and mirtazapine are examples of atypical antidepressants. When patients have sexual adverse effects from SSRIs or SNRIs, they are frequently recommended as monotherapy or as augmenting medications.
  • Amitriptyline, imipramine, clomipramine, doxepin, nortriptyline, and desipramine are tricyclic antidepressants (TCAs).
  • Tranylcypromine, phenelzine, selegiline, and isocarboxazid are examples of monoamine oxidase inhibitors (MAOIs). Because of the high prevalence of adverse effects and fatality in overdose, MAOIs and TCAs are not routinely utilized.
  • Other drugs that may be used to increase antidepressant effectiveness include mood stabilizers and antipsychotics.


The Role of Yoga and Meditation in Depression Management:

Role of Yoga and Meditation

Yoga originating in ancient India is recognized as a form of alternative medicine that uses the practice of the mind-body. Yoga's philosophy is based on 8 limbs that are better described as ethical principles for living a meaningful and purposeful life. For managing depression:

  • Can relax muscles, resulting in reduced aches and pains
  • Create a balanced energy
  • Decreased breathing and heart rate
  • It lowers blood pressure and cortisol levels
  • Increase blood flow
  • Reduce stress and anxiety due to calmness
  • Improve pre-existing medical conditions such as arthritis, cancer, mental illness, and more.


Treatment of major depressive disorder (MDD) in children and adolescents

Psychotherapy is important for both patients and their families so everyone is aware of the treatment plan and goals. When education is given, treatment is decreased. Mental education may include knowledge of: signs and symptoms of depression, clinical course of illness, risk of exacerbation, treatment options, and parental advice on how to interact with depressed young people.

According to the Sandra Mullen study, psychotherapy, along with medications, is often the recommended treatment for major depressive disorder (MDD) in children and adolescents that are diagnosed for depression, suicidal thoughts, and transition hypomania/mania.


Treatment for bipolar depression

Bipolar depression remains a clinical challenge. Treatment options are limited, especially in the management of the acute phase of bipolar depression. There are currently only three approved drug therapies - OFC, quetiapine (immediate or extended-release), and lurasidone (lithium monotherapy or adjuvant therapy or valproate). All three agents have similar efficacy profiles. But they differ in terms of durability.

Unapproved agents and treatments

Nonpharmacologic drugs such as lamotrigine, anti-depressants, modafinil, pramipexole, ketamine, and electroconvulsive therapy (ECT) are often prescribed to treat acute bipolar depression.


Treatment for recurrent depression:

Some patients may experience repeated episodes of depression throughout their lives unless maintenance therapy is used to prevent relapse. Treatment should include psychotherapy and pharmacotherapy, and the dosage should generally not be reduced after remission.


Differential Diagnosis

It is critical to rule out depressive disorder caused by another medical condition, substance/medication-induced depressive disorder, dysthymia, cyclothymia, bereavement, adjustment disorder with depressed mood, bipolar disorder, schizoaffective disorder, schizophrenia, anxiety disorders, and eating disorders when evaluating for MDD. Depressive symptoms can develop as a result of the following factors:

  • Neurological causes such as cerebrovascular accident, multiple sclerosis, epilepsy, Parkinson disease, and Alzheimer disease 
  • Endocrinopathies such as diabetes, thyroid disorders, and adrenal disorders
  • Metabolic disturbances such as hypercalcemia, hyponatremia
  • Medications/substances of abuse: steroids, antihypertensives, anticonvulsants, antibiotics, sedatives, hypnotics, alcohol, stimulant withdrawal
  • Nutritional deficiencies such as vitamin D, B12, B6 deficiency, iron or folate deficiency
  • Infectious diseases such as HIV and syphilis
  • Malignancies



Depressive episodes in major depressive disorder can persist for 6 to 12 months if left untreated. Approximately two-thirds of people with MDD consider suicide, and 10 to 15% commit themselves. MDD is a chronic, recurring condition; the recurrence rate after the first episode is around 50%, 70% after the second episode, and 90% after the third episode. Approximately 5 to 10% of people with MDD develop bipolar disorder.

Patients with moderate episodes, the lack of psychotic symptoms, improved treatment compliance, a robust support system, and adequate premorbid functioning have a positive prognosis for MDD. In the presence of a concomitant mental condition, personality disorder, multiple hospitalizations, and advanced age of onset, the prognosis is poor.



MDD is one of the world's top causes of disability. It not only causes severe functional impairment, but it also has a negative impact on interpersonal connections, decreasing one's quality of life. Individuals suffering from MDD are at a significant risk of acquiring comorbid anxiety and drug use disorders, which enhances their risk of suicide.

Diabetes, hypertension, chronic obstructive pulmonary disease, and coronary artery disease can all be exacerbated by depression. Individuals who are depressed are more likely to engage in self-destructive conduct as a coping technique. If untreated, MDD may be quite debilitating.



Major depressive disorder (MDD) was classified as the third leading cause of illness burden worldwide by WHO in 2008, with the condition anticipated to rank first by 2030. 

It is diagnosed when a person has a consistently low or depressed mood, anhedonia (loss of interest in pleasure activities), feelings of guilt or worthlessness, a lack of energy, poor concentration, appetite changes, psychomotor retardation or agitation, sleep difficulties, or suicidal thoughts.

For the effective and successful treatment of MDD, a multidisciplinary approach is required. These collaborative services include primary care physicians and psychiatrists, as well as nurses, therapists, social workers, and case managers. Depression screening in primary care settings is critical.