Causes & Symptoms of Depression

Learn about depression

Everyone will go through periods of frustration, sadness, and despair in their lives. While upsetting, these emotions help individuals to process their feelings in healthy ways. However, when these emotions continue on for long periods of time, or happen so frequently and severely that an individual is not able to properly function, then he or she might be struggling with a depressive disorder. In many aspects, those who develop depressive disorders turn to self-medication by abusing drugs and/or alcohol to curb their feelings of pain. This is a poor decision, as engaging in this type of behavior can bring on a variety of dangerous outcomes, including the exacerbation of depressive symptoms and the potential for substance use disorder to develop.

Depressive disorders include a number of disorders that are distinguished by feelings of emptiness, sadness, and/or irritability that are accompanied by intrusive cognitive and somatic changes. The most common forms of depressive disorders are major depressive disorder, persistent depressive disorder, premenstrual dysphoric disorders, and substance/medication-induced depressive disorder:

Major depressive disorder: Those who go through five or more of the following symptoms for the majority of the day mostly every day for two weeks, and who have severe distress or functional impairment as a result, might meet the criteria for major depressive disorder:

• Hypersomnia or insomnia
• Psychomotor retardation or agitation
• Fatigue or loss of energy
• Depressed mood
• Markedly diminished interest or pleasure in all or most activities
• Significant change in appetite or unintentional change in weight
• Feelings of worthlessness and/or excessive or inappropriate guilt
• Indecisiveness or diminished ability to think or concentrate
• Recurrent thoughts of death, suicidal ideation, planning for suicide, or attempting suicide

Persistent depressive disorder: The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) states that symptoms that used to be indicative of major depressive disorder and dysthymic disorder were consolidated into persistent depressive disorder. The symptoms needed for a diagnosis of this form of depressive disorder include depressed mood for most of the day, for the majority of day, for two years minimum, plus two of the following symptoms:

• Overeating or poor appetite
• Disrupted sleep patterns, including insomnia or hypersomnia
• Sense of hopelessness
• Poor self-esteem
• Fatigue or low energy
• Poor concentration and/or problems making decisions

Within the two-year-long period that an individual goes through these symptoms, he or she who has persistent depressive disorder will not be asymptomatic for more than two months.

Premenstrual dysphoric disorder: The main features of this form of depressive disorder are repeated occurrences of mood lability, anxiety symptoms, dysphoria, and irritability during the premenstrual phase of a woman’s menstrual cycle. The symptoms of this form of depressive disorder will fade during or shortly after the start of menses. Someone with premenstrual dysphoric disorder will display five of the following symptoms, with at least one from each group:

Group 1

• Depression, hopelessness, and self-deprecating thoughts
• Anxiety, tension, and/or feelings of being on edge
• Mood swings or increased sensitivity to rejection
• Increased irritability or anger

Group 2

• Disrupted sleep patterns, including hypersomnia or insomnia
• Feeling overwhelmed
• Problems with concentration
• Lethargy, fatigue, or significant lack of energy
• Breast tenderness or swelling, joint or muscle pain, weight gain, and other physical symptoms
• Significant change in appetite, including overeating or specific food cravings
• Decreased interest in usual activities

In order to be diagnosed with premenstrual dysphoric disorder, an individual must experience these symptoms during the majority of her menstrual cycles from the previous 12 months.

Substance/medication-induced depressive disorder: To obtain a diagnosis of this form of depressive disorder, one must meet the following criteria:

• The disturbance does not occur exclusively during delirium, and the disturbance causes significant stress or impairment in important areas of functioning
• An individual experiences prominent and persistent depressed mood or significantly diminished interest and/or pleasure in all or almost all activities
• The disturbed mood is not better explained by a non-substance-related depressive disorder
• Evidence exists that these symptoms occur during or soon after substance intoxication or withdrawal, and the substance in question is capable of producing these symptoms

While depressive disorders can cause a great deal of psychological pain, they are are treatable. With the appropriate professional treatment, those who have developed major depressive disorder, persistent depressive disorder, premenstrual dysphoric disorder, or substance/medication-induced depressive disorder can defeat their symptoms and develop happier, healthier lives.

Depression statistics

The National Alliance on Mental Illness (NAMI) reports that 14.8 million people are affected by major depression, or 6.7% of the American adult population aged 18 and older. The National Institute on Mental Health (NIMH) states that depression in adults is most common for those between the ages of 18 and 25, then it is among those between the ages of 26 and 49. Following behind is the 50 and older age group. Depressive disorders are more common in women than in men. For instance, the 12-month prevalence of a major depressive episode is 8.1% for adult women as compared to 5.1% of adult men within the United States.

Causes and risk factors for depression

The development of a depressive disorder can be brought on by a number of causes and risk factors that tend to work in concert. Below are some of the most common risk factors that can determine an individual’s likelihood of developing a depressive disorder:

Genetic: Depression has a strong genetic tie. The American Psychiatric Association (APA) states that the risk of developing major depressive disorder is 400% more likely in those with parents or siblings who have this disorder.

Environmental: Adverse experiences in childhood, as well as stressful life events, can be some of the major risk factors for the development of a depressive disorder, especially when an individual has a history of these types of events.

Risk Factors:

• Loss of parent through separation, divorce, or death
• Substance abuse
• Age (depression is more common within the 18-29 age group)
• Negative affectivity
• Trauma
• Family history of depression
• Gender (depression is more common among women)

Signs and symptoms of depression

The appearance of a depressive disorder will vary from individual to individual, and will be based on a number of factors, such as the type of depressive disorder one is experiencing. Below are some of the most common signs and symptoms that someone is battling a depressive disorder:

Behavioral symptoms:

• Drop in academic or occupational performance
• Jitteriness
• Tearfulness
• Angry outbursts
• Slowed speech and/or decrease in volume, amount, and inflection

Physical symptoms:

• Change in weight
• Headaches and stomachaches
• Fatigue
• Insomnia
• Change in appetite

Cognitive symptoms:

• Indecisiveness
• Racing thoughts
• Difficulty focusing
• Difficulty concentrating
• Slowed thoughts
• Distractibility

Psychosocial symptoms:

• Sadness, shame, and guilt
• Irritability
• Suicidal ideation

Effects of depression

When depressive disorders go untreated, a variety of negative repercussions can occur within an individual’s life, including:

• Strained or ruined interpersonal relationships
• Dangerous, reckless, and risky behaviors
• Suicidal ideation
• Suicide attempts
• Onset of substance abuse and substance use disorders
• Sleep disorders
• Withdrawal and isolation
• Self-harm
• Diminished occupational performance, job loss, and unemployment
• Family discord

Depression and co-occurring disorders

Those who develop a depressive disorder are also at a greater risk for experiencing the following co-occurring disorders:

• Eating disorders
• Substance use disorder
• Anxiety disorders
• Obsessive-compulsive disorder (OCD)
• Posttraumatic stress disorder (PTSD)
• Substance use disorders