What Is Depression? Everything You Need to Know About This Mood Disorder

Medically Reviewed by Madeline Hubbard, RN, BSN

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What Is Depression?

Some feelings of sadness or fluctuations in mood are normal parts of the human experience. However, there are times when one’s mood can begin to interfere with daily life. Depression is one example of what is known as a “mood disorder.” This condition includes feelings of sadness, helplessness, and hopelessness that do not go away on their own. It is common for people who are depressed to lose interest or have difficulty participating in many important aspects of life, including work, school, friendships, family, sex, and social relationships.

Moreover, depression is a common condition that impacts over 264 million people of all ages, races, and genders. Due to continued social stigma, access barriers, and lack of resources, it is estimated that only 15 – 24% of people receive treatment for depression in low- and middle-income regions of the world. When left unsupported, depression carries a high risk of significant disability and/or death by suicide.

To make things more complicated, depression can be difficult to understand and discuss, especially with friends and family. Those experiencing depression might feel lost, isolated, or worried about judgment from their peers. It is important to remember that depression is a real illness that warrants treatment and that managing it is possible.

Symptoms & Warning Signs

Depression is a very personal condition, which means symptoms can vary greatly from person to person. Episodes of depression may be mild, moderate, or severe and can come and go or last for months or years at a time. For most people, the onset of depression is gradual; symptoms will begin subtly and then worsen over time.

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 These are some of the common emotional and behavioral symptoms associated with depression:

  • Feeling sad, empty, or tearful
  • Feeling worthless or guilty with self-blame
  • Loss of interest or pleasure gained from activities
  • Agitation or irritability
  • Decreased energy, fatigue, sleep disturbances (too few or too many hours)
  • Changes in appetite with weight loss or weight gain
  • Difficulty concentrating, thinking/speaking, or making decisions
  • Frequent thoughts of death or suicide

Depression may also be experienced more physically, with some individuals reporting back pain, headaches, or body aches that cannot be otherwise explained. If any combination of the symptoms listed above is interfering with your daily functioning, it may be time to seek help from a medical or behavioral health professional.

Causes & Risk Factors

The precise cause of clinical depression remains unknown, and people experience symptoms for a variety of reasons. For some, symptoms could be related to a specific event. A person might feel sad and have difficulty functioning for a short period of time when coping with a challenging or traumatic situation. Other people may experience depression for no identifiable reason over a prolonged period of time.

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There are many factors that have been linked with increased likelihood of depression onset:

  • Biological Factors: Neural circuits that regulate mood depend on neurotransmitter activity in the brain. Decreases in certain neurotransmitter chemicals (serotonin, norepinephrine, and dopamine) likely play a role in depression, for some.
  • Genetic Factors: Those with family members that have been diagnosed with depression are more likely to experience it themselves. Further research is needed to determine which genetic changes might contribute to this outcome.
  • Hormonal Factors: Changes in the body’s hormone levels can have an impact on overall mood. This might be related to thyroid functioning, or life events that naturally impact hormone levels, like puberty, pregnancy, or menopause.

The above factors might predispose a person to experience depression. In addition, the following environmental factors — or unpredictable life events — can co-occur and are associated with a higher risk of depression onset. These include:

  • Physical or sexual abuse
  • Death or loss of a loved one
  • Loss of a job or financial stressors
  • Substance abuse
  • Chronic illness or disability
  • Certain medications

Assessment & Diagnosis

Depression symptoms can often be overlooked or easy to miss. Sometimes, a person’s family or friends can play an important role in pointing out that they seem depressed or their behaviors have changed. Seeking help if you are (or someone you care about is) feeling depressed can be a vital first step in diagnosing the disorder and finding support. Depression can be diagnosed by any of the following professionals:

  • Primary care providers
  • Psychiatrists
  • Psychologists

Moreover, there are no laboratory tests or physical exams available to diagnose depression. That said, a healthcare professional may order blood tests to check for other possible conditions that can cause symptoms similar to depression. These tests may help identify hypothyroidism, infections, metabolic problems, or vitamin and hormone level changes. They may also provide screening for depression using a questionnaire that assesses for frequency and severity of recent symptoms.

After this initial screening, your primary healthcare provider may offer a referral to a behavioral health specialist, like a psychiatrist or psychologist. When these specialists assess a patient for depression, they collect information about personal and family health history, recent mood and behaviors, relationship dynamics, professional satisfaction, exercise habits, and overall reported quality of life. 

Primarily, a clinician will try to ascertain whether there are any patterns in what you communicate about your life that indicate a mood disorder. They will use diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) that help determine which diagnosis best aligns with your specific presentation and timeline.

Depression symptoms must have lasted for at least two weeks in order to be clinically diagnosed. Some types of depression that a provider might identify include:

  • Major Depressive Disorder: The clinical term for depression that can be persistent or periodic.
  • Seasonal Affective Disorder (SAD): A form of depression that occurs during particular seasons. Most patients with SAD feel depressed in the autumn and winter when the weather is cold and there are fewer daylight hours.
  • Peripartum Depression: Occurs during or following pregnancy and birth.
  • Premenstrual Dysphoric Disorder: Occurs prior to menstruation each month and can involve severe symptoms of depression.
  • Bipolar Disorder: Involves extreme mood swings characterized by periods of depression as well as periods of euphoria or mania.

Treatment Options to Manage Depression

After one receives a depression diagnosis, they can pursue various treatment options, which correspond to the severity of symptoms and the patient’s treatment preferences. Typically, treatment can take place on an outpatient basis, but more intensive treatment programs, or inpatient stays, are available. Hospitalization may be necessary for individuals who are at an immediate risk to themselves or others. 

Most often, individuals with depression can find significant relief from their symptoms with one or more of the following approaches:

  • Individual Therapy: Also called psychotherapy or “talk therapy,” there are several approaches that mental health professionals may take to help address depression symptoms, support coping skills, or adjust beliefs, behaviors, and relationships.
  • Medication: Psychiatric medications, called antidepressants, can be prescribed by a healthcare professional. These medications can take up to four weeks to take effect, and multiple trials may be necessary to find one that is right for you.
  • Brain Stimulation Therapy: Transcranial Magnetic Stimulation (TMS), or Electroconvulsive therapy (ECT), directly stimulate the brain, and are often pursued if antidepressants — or the combination of medication and talk therapy — are not effective.
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In addition to these treatment options, there are some measures that you can take to mitigate your symptoms and manage your depression. Sometimes, it is possible to address mild depression before it becomes a more significant problem. Patients looking to mitigate their depression may try some of the following tactics, including: 

  • Seek Education and Emotional Support: If you are a parent, teach your child about depression and its warning signs. Children and adolescents do not always understand what they are feeling, and young people might feel ashamed to discuss their feelings openly. Try to help them feel comfortable by providing information and opening yourself up as a source of support.
  • Exercise: Break the cycle of a sedentary lifestyle by exercising regularly. Even light exercise can help you clear your mind and relieve stress to create balance in your life. Many people report that they feel an improvement in their mood and quality of life when working out.
  • Schedule Annual Physical Exams: When you get your yearly physical, your provider will likely ask you a series of questions to determine whether you are at risk for depression. This can be a great way to assess your mood and any recent changes.
  • Find Social Support: Find a group of friends or a community to share common interests and make an effort to participate in activities that keep you motivated to enjoy life. Try volunteering or joining a club. These networks can become sources of support if you are feeling down or depressed.
  • Get Enough Sleep: Healthy sleep habits can potentially prevent you from becoming depressed. Do your best to get a full night’s rest every night. Talk to a healthcare provider if you have trouble falling asleep or if you wake up throughout the night.
  • Maintain a Balanced Diet: By getting appropriate nutrition, you may be able to improve symptoms such as fatigue and irritability. Improvements to your diet can help determine whether you are experiencing any other conditions that are causing your depression. Avoiding alcohol and drug use can also greatly impact mood.

Next Steps in Managing Depression

If you notice behavioral or mood changes in yourself (or a loved one) that last more than two weeks, speak with a healthcare professional so you can work together to find support and an appropriate treatment plan to provide relief of your symptoms.

No matter the severity, if you are ever having thoughts of suicide or self harm, contact a suicide prevention hotline, such as the National Suicide Prevention LifelineThe Trevor Project or Trans Lifeline.

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