Depression Causes, Statistics, Signs, Symptoms & Side Effects

What is Depression?

Severe depression can be referred to by several names, such as clinical depression, biological depression, major depressive disorder, recurrent depression, or even “the blues”. All of these refer to the mental disorder characterized by feelings of sadness and depression that typically last for unremitting periods of time.

While people can experience a low mood on occasion, depression is a mental disorder that can be incapacitating to the sufferer. Men or women who struggle with depression will have chronic sadness coupled with loss of interest in pleasurable activities and low self-esteem.

The Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) has recognized five subtypes of major depressive disorder, which include the following:

  • Melancholic depression: Loss of pleasure in most or all activities
  • Atypical depression: Characterized by mood reactivity and positivity, as well as several physical symptoms such as weight gain and excessive sleepiness.
  • Catatonic depression: Severe form of depression that involves disturbances to motor behavior
  • Postpartum depression: Intense depression experienced by women after giving birth.
  • Seasonal affective disorder: Form of depression in which episodes occur in the fall or winter and resolve in the spring.

No matter the form, depression can be burdening to both the sufferer and their loved ones, particularly as their behavior and mental health are altered significantly as their condition becomes disabling.

If you or a loved one has been suffering from depression, it is important that you seek the necessary professional help you need to heal from this physical and psychological burden.

Depression Statistics

Gathering more information about depression is helpful in better understanding this condition and those who it can potentially affect. The following are important statistics about depression that give greater insight into details about how sufferers are impacted:

  • The most common time of onset of depression is between the ages of 20 and 30 years, with a later peak between 30-40 years [1].
  • In the United States, around 3.4% of people with major depression commit suicide, and up to 60% of people who commit suicide had depression or another mood disorder [2].
  • Insomnia affects at least 80% of depression people [3].
  • A National Comorbidity Survey reported that 51% of those with major depression also suffered from lifetime anxiety [4].
  • Anxiety symptoms can have a major impact on the course of a depressive illness, with delayed recovery, increased risk of relapse, greater disability and increased suicide attempts [5].

Causes of Depression

Depression is likely the culmination of several factors, such as biological, psychological and social causes. Biological causes that may contribute to depression include hormonal imbalances, abnormal brain structures, use of certain medications, or family history of depression.

Psychological factors that may play a part in the development of depression include the experience of a traumatic event, inability to cope with negative situations, low-self esteem, or grief/loss.

Social implications may also be involved in the causes of depression, including factors such as social isolation, child abuse, disturbances in family function, lack of social support, and stressful life events.

Depression can also be associated with other co-occurring disorders, such as eating disorders or substance abuse. Depression is a complex mental health issue that can have serious complications if left untreated. For these reasons, it is recommended professional help be sought to effectively heal from depression.

Signs and Symptoms of Depression

Depression, or depressive disorders, can be characterized by numerous signs and symptoms. The following are possible symptoms of depression:

  • Persistent sadness, anxiety, or low mood
  • Feelings of negativity, hopelessness, or despair
  • Decreased energy, chronic fatigue
  • Difficulty concentrating
  • Sleep disorders, such as insomnia or oversleeping
  • Restlessness
  • Irritability
  • Headaches
  • Digestive disorders
  • Chronic pain
  • Loss of interest in pleasurable activities
  • Suicidal ideations

If you or your loved one has been experiencing any of these above symptoms as a result of depression, seek out professional help immediately to work through these pertinent issues.

Depression Effects

Depression can severely handicap the life of you or your loved one struggling with this mental health disorder. If depression is left untreated, it can quickly evolve into more damaging and chronic symptoms.

Understanding how depression may affect the different aspects of your life may encourage you to get the help you need and deserve. The following are some of the effects of depression:

Physical Effects – Depression can be physically exasperating. These are some physical effects that may be experienced:

  • Suicidal ideations
  • Chronic fatigue
  • Chronic pain
  • Sleep disorders
  • Abuse of drugs or alcohol
  • Difficulty concentrating
  • Reduced sex drive
  • Digestive problems
  • Headaches
  • Increased appetite, or weight gain
  • Lethargy

Psychological Effects – Depression can be debilitating to mental health, particularly if you are lacking adequate support or professional help. Some of the psychological effects that may be experienced include:

  • Low self-esteem
  • Increased feelings of anxiety
  • Feeling sad, hopeless, or in despair
  • Increased irritability
  • Identify changes
  • Emotional detachment

Finally, depression can have negative consequences on your social life. Social effects of depression include:

  • Decreased performance at work or school
  • Isolation from loved ones
  • Lack of enjoyment in hobbies or activities once enjoyed
  • Avoidance of social events or function

Depression Treatment

If you or a loved one has found yourself stuck in a burdening relationship with depression, you have likely felt overwhelmed with the negative, despair, and sadness you have felt on a daily basis. Living with depression may be preventing you from enjoying a life you once lived, though the possibility for healing always exists.

By seeking the appropriate help and care you need, you can find the resources to address your depression in an effective manner. Attempting to deal with your depression alone can possibly further perpetuate you into fear or isolation. A depression treatment center can provide the tools and resources you need to recover and heal from any form of a depression disorder.


[1]: “Major Depressive Disorder”. American Medical Network, Inc. Retrieved 2011-01-15.
[2]: Barlow DH. Abnormal psychology: An integrative approach (5th ed.). Belmont, CA, USA: Thomson Wadsworth; 2005. ISBN 0-534-63356-0.
[3]: “Bedfellows:Insomnia and Depression”. Retrieved 2010-07-02.
[4]: Kessler RC, Nelson C, McGonagle KA. Comorbidity of DSM-III-R major depressive disorder in the general population: results from the US National Comorbidity Survey. British Journal of Psychiatry. 1996;168(suppl 30):17–30. PMID 8864145.
[5]: Hirschfeld RMA. The Comorbidity of Major Depression and Anxiety Disorders: Recognition and Management in Primary Care. Primary Care Companion to the Journal of Clinical Psychiatry. 2001;3(6):244–254. PMID 15014592.

Last Updated & Reviewed By: Jacquelyn Ekern, MS, LPC on April 15th, 2013
Published on, Addiction Online Help