Depression: Statistics, Causes, Signs, & Symptoms

Learn about depression

Depression is a mood state that can significantly impact an individual’s entire life; major depression is a condition that goes far beyond feeling sad or upset. Depression affects a person’s mood, thoughts, feelings, behaviors, and physical health. Severe depression can result in losing the ability to feel pleasure in formerly-enjoyable activities and/or social relationships. People struggling with depression struggle with a loss of energy and motivation which can negatively influence the ability to be productive at work or school. Depression – notably untreated depression – is a major risk for suicide due to the deep despair and hopelessness depression causes. Suicide may feel like the only way to escape the pain. If you or someone you love is considering suicide, don’t hesitate to call 911 immediately – this is a medical emergency.

Sometimes, depression can become so severe that some people feel unable to function in major areas of their life, which can lead to feelings of helplessness and hopelessness. While depression can cause a significant problem in a person’s life, there is much hope. Even the most severe cases of depression can be treated with a combination of self-care approaches, therapeutic interventions, and medications.

Depression statistics

Approximately 7% of the U.S. population suffers from depression, though this rate varies significantly according to gender and age. While there are no gender differences in childhood, starting in adolescence a difference begins to become evident. Overall, women are 70% more likely to suffer from depression during their lives than men. People aged 18 to 29 are significantly more likely to suffer from depression than individuals over the age of 60. The most common age of onset is in a person’s 20s though depression can begin late in life – especially in men.

Causes and risk factors for depression

While there does not appear to be a single cause for depression, there are a number of environmental, genetic, and physical reasons one person develops depression while another does not. The most commonly cited causes for depression can include:

Neurotransmitters: There are several chemicals in the brain that are involved in mood regulation including serotonin and dopamine. When these levels of neurotransmitters are not properly balanced, depression can result.

Brain Structures: Through neuroimaging studies (MRIs, CT Scans), researchers have noted there to be differences in the size and shape in areas of the brain responsible for mood, sleep, and appetite although these changes have not been conclusively linked to depression.

Genetics: Depression has been found to run in families – people who have a first-degree relative who has depression are at greater risk for developing the disorder than those without a similar family history. However, many people who develop depression do not have a family history of the disorder. Research suggests that it’s likely that there are multiple genes working together that are responsible for depression rather than a single gene.

Psychological Factors: Some people are born with a personality that includes a depressive way of thinking – they believe a positive event is related to others, while negative events are always their fault.

Environmental Factors – There are many negative life events and major stressors associated with the onset of depression, including job loss, loss of loved one, trauma, problematic relationships, and lack of a sufficient social network.

Signs and symptoms of depression

Depression may persist for a long period time, remaining undiagnosed, as the symptoms a person experiences may not always include easily identifiable as being depression. Symptoms and signs of depression will vary based upon age, length of symptoms, and individual temperament. Common symptoms of depression can include:

Mood symptoms:

• Depressed mood almost every day for long periods of time
• Sadness
• Loss of interest or enjoyment in practically all activities
• Sense of worthlessness or guilt with no reason
• Loss of interest in sexual activities or desire

Physical symptoms:

• Lack of energy
• Increase or decrease in appetite
• Increase or decrease in sleep
• Somatic complaints, in particular pain
• Feeling emotionally numb
• Irritability

Behavioral symptoms:

• Social withdrawal
• Slowed speech or poverty of speech
• Psychomotor disturbances – agitation or slowed movement
• Loss of efficiency completing tasks

Psychological symptoms:

• Hopelessness
• Loss of self esteem
• Concentration and memory problems
• Trouble making decisions
• Distractibility
• Lack of motivation
• Thoughts of suicide or having a plan in place

Effects of depression

Left untreated, depression can lead to significant impairment in an individual’s ability to enjoy life. The effects of depression can range from minor annoyances to death. With proper interventions, depression can be treated and managed throughout the lifetime. The most common effects of depression can include

• Poor coping skills
• Pain especially headaches and stomach pain
• Sexual dysfunction
• Attempts to self-medicate with drugs or alcohol
• Anxiety
• Decreased immune system functioning
• Family and marital problems
• Rejection at school or work
• Social isolation
• Self-mutilation
• Suicide
• Premature death in medical conditions

Depression and co-occurring disorders

There are a number of disorders that frequently occur alongside depression and depressive disorders. The most common co-occurring, co-morbid conditions can include:

• Anxiety disorders
• Panic disorder
• Obsessive-compulsive disorder (OCD)
• Alcoholism
• Substance abuse
• Eating disorders
• Borderline personality disorder