What Is Depression?

By: Jayson Tripp, MD


While it’s normal to experience periods of sadness throughout your life, persistent low moods that feel inescapable and consume your everyday life could be a sign of a more serious mental issue. If you haven’t experienced a mental illness before, you may find yourself asking: what is depression?

Depression is a common mood disorder with over 3 million cases each year in the United States. Though the exact biological cause remains under research, it is believed to be caused by chemical imbalances in the brain. PET scans of brains with depression also show a significant decrease in activity, suggesting that depression can physically change neural pathways within the brain. Its symptoms can be debilitating for patients, affecting how you feel, think, interact with people, and maneuver through daily activities. Depression is far more than just a bad day. It isn’t something you can simply “get a grip” on, and it is just as valid as any physical illness. Many patients require long-term treatment, and in serious cases, depression can be life-threatening without proper help.


To be officially diagnosed with depression, you must experience five or more of the following symptoms for at least two weeks:

  • Intense and enduring feelings of sadness, emptiness, and/or hopelessness
  • Loss of interest in most or all enjoyable activities
  • Irritability and/or outbursts over small inconveniences
  • Trouble sleeping or oversleeping
  • Decreased appetite or sudden weight loss
  • Sluggish speaking, thoughts, or body movement
  • Forgetfulness or inability to focus
  • Increased anxiety or restlessness
  • Recurring thoughts of death and/or suicide

(NOTE: Although checklists of symptoms can be helpful in identifying depression-related behavior in yourself or a loved one, only a doctor can determine an actual diagnosis)

Types of Depression

The answer to the question “what is depression?” is not always straightforward. It can look different for everyone and manifest in many forms, such as:

  • Major Depressive Disorder (MDD) — Regarded as the classic depressive type, MDD is identified in patients with at least five diagnostic symptoms of depression.
  • Postpartum Depression — This form of depression typically manifests in mothers either during pregnancy or shortly after giving birth (within a few weeks to a year). It is commonly a short-term disorder, but it can be just as severe as any other form of depression.
  • Seasonal Affective Disorder (SAD) — While SAD shares much of the same symptoms of MDD, patients with this subtype will experience their symptoms during a specific part of the year (often beginning in fall or winter and lasting until spring) due to seasonal changes affecting the body’s internal clock.
  • Persistent Depressive Disorder (PDD) – PDD (sometimes called dysthymia) is a milder yet enduring form of depression. Though symptoms may not be as intense as MDD cases (allowing the patient to function in daily activities), PDD patients will experience melancholy or a lack of joy for most of their day over a period of two years or more.

Depression can also be categorized by the length of time/frequency with which the patient experiences depressive episodes.

  • Single episode depressive disorder: The patient experiences a single depressive episode lasting at least two weeks.
  • Recurrent depressive disorder: The patient experiences two or more depressive episodes.
  • Bipolar disorder: The patient experiences frequent depressive episodes that alternate with manic episodes due to extreme mood swings.

Risk Factors

Though depression can happen to anyone and at any age, research does suggest that depression can also be associated with genetic, psychological, and environmental risk factors. These factors can include:

  • A personal or family history of depression
  • Drug or alcohol abuse
  • Major life changes
  • Past abuse or trauma
  • Long-term health problems
  • High amounts of stress
  • Side effects from certain medications

Treatment Options

Once a doctor diagnoses a patient with a depressive mood disorder, treatment often includes an antidepressant prescription or a form of therapy. Some patients will find that their symptoms ease with medication, while others may experience no change or find the negative side effects too extreme for them to continue treatment. Newer treatments, such as the transcranial magnetic stimulation (TMS treatment) and ketamine therapy treatments offered at Serenity, can be used to treat particularly difficult cases of treatment-resistant depression by stimulating mid-brain activity and creating new neural pathways within the brain.

When to See a Doctor

Though depression can be a devastating disease when left untreated, there is always hope. If you find yourself experiencing multiple symptoms of depression for an extended period, seek help from a medical or mental health professional as soon as possible.

If you begin to experience suicidal thoughts, call 911 or a local emergency number such as a suicide hotline immediately. More resources include:

  • The National Suicide Prevention Lifeline at 1-800-273-TALK (1-800-273-8255). Press “1” at the end of this number to reach the Veterans Crisis Line.
  • Text a crisis text line such as 741741 to speak with a trained crisis worker.
  • Reach out to a loved one or a trusted friend.
  • Contact a dependable member of your faith community.

How to Get Help

Because depression has so many forms and causes, it’s important to find a qualified medical professional to evaluate your symptoms and help you develop a depression treatment plan that fits your symptoms. At Serenity Mental Health Centers, we strive to ensure a completely individualized care plan for your needs and lifestyle. Our clinicians specialize in depression and offer a range of treatment options for a better chance of success. You don’t have to face your depression alone. We can help you reclaim your life from mental illness. Reach out to us to schedule an appointment today.

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*All information subject to change. Images may contain models. Individual results are not guaranteed and may vary.