What is Depression?

Depression is a mental health condition characterized by a persistent lack of positive mood and the inability to enjoy experiences that are typically pleasurable. It can range from mild to severe, affecting how individuals think, feel, and behave daily.¹ According to the Substance Abuse and Mental Health Services Administration, in 2021 21.0 million adults and 5.0 million adolescents in the United States experienced at least one major depressive episode. About 39.0% of these adults and 59.4% of these adolescents did not receive any treatment.²

Depression is a leading cause of disability worldwide³, often developing subtly over time. This gradual onset can make it difficult to recognize, with many people becoming accustomed to their symptoms without realizing they are experiencing depression. It is more than just feeling sad or going through a rough patch; depression can significantly alter one's thoughts, feelings, and daily functions, including work performance, appetite, energy levels, sleep patterns, and overall enjoyment of life.⁴

Contrary to some misconceptions, not all individuals with depression appear visibly despondent or unable to get out of bed. While severe depression may manifest in such ways, those with mild or moderate depression might still manage daily activities, making it harder to identify their condition. Nonetheless, depression is marked by its persistence and pervasiveness, not improving on its own and potentially worsening over time if left untreated. This can lead to a pessimistic outlook, feelings of guilt and worthlessness, and, at its worst, an increased risk of suicide.⁴

Let’s learn more about depression, including its symptoms, the factors that can cause it, and several specific types of this condition. If you or someone you know is struggling with depression, you’ll also learn tips for coping with symptoms as well as information on effective medication and treatment options.

Symptoms of Depression

Depression impacts the way people think about themselves and the way they perceive the world around them. It can make someone feel worthless, hopeless, or unnecessarily guilty, and create a lack of confidence. One of the most challenging and frustrating symptoms of depression is a loss of interest in things that someone once enjoyed; some people describe this as feeling numb. Many people experience times when they cry very easily, feel irritable or are more prone to anger. Depression can impact areas of one’s physical health like appetite, sleep, energy, and cause unexplainable aches or pains.⁴

Signs of Depression

Some common signs of depression include⁴

• Anhedonia, or lack of interest or pleasure in life
• Feeling down or unhappy, even when good things are happening
• Feeling tired, and lacking energy
• Disrupted sleep
• Feeling anxious or irritable
• Becoming easily angry
• Changes in appetite, such as eating more or less than normal
• Difficulty focusing attention and concentration
• Withdrawal from others
• Feeling hopeless or helpless

Causes of Depression

Depression impacts 280 million people worldwide. People experience depression for many reasons, and it has no single cause. Depression can appear in one’s life at any age, regardless of gender, race or ethnicity, and socioeconomic status.³

There are many known contributing factors that influence whether an individual develops depression or not. For example, depression can occur due to factors that are genetic, biochemical (related to the neurotransmitters in the brain), psychological, and environmental. For each individual, there are likely to be several contributing factors, which can include a genetic predisposition, personality and temperament, neurological processes and functioning, stressful life events, trauma and abuse, adverse childhood experiences, physical health problems, and medical disorders.³

Genetic predisposition and physiological factors can be identified, understood and successfully addressed. We also know that there are some medical problems and medication issues that can cause depression, like hypothyroidism, or heart disease.

Environmental factors may include significant losses and traumas, such as the early loss of a parent, sexual or verbal abuse or violence in the home, or other adverse childhood experiences such as frequent criticism or the absence of needed affection. These environmental events can all manifest and express themselves as depression.²

Types of Depression

Major Depressive Disorder

Major Depressive Disorder or MDD is a common but serious mood disorder that impacts the way a person feels, thinks, and behaves. For an adult to be diagnosed with major depressive disorder, they must have 5 or more symptoms of depression nearly every day for at least two weeks. The symptoms of MDD can be related to physical health, mood, cognition, and behavior.¹

Other symptoms of major depressive disorder include:¹

• unintentional changes in weight or appetite
• sleeping more or less than usual
• restlessness or sluggishness
• low energy or fatigue
• feelings of worthlessness or guilt
• trouble concentrating
• thoughts of death or suicide, suicidal ideation, or suicide attempts

Major Depressive Disorder is diagnosed by a psychiatrist, psychologist, or healthcare professional after interviewing to understand a person’s symptoms, mental health and medical history.

Seasonal Depression

Seasonal affective disorder (SAD) is a specific type of depression that is commonly known as seasonal depression or the winter blues. It’s a pattern of low mood and other symptoms commonly associated with depression that occurs in a seasonal pattern, usually during the months of the year when there are fewer hours of sunlight. The time when symptoms start can depend on the person but might begin as early as the late summer months, fall, or winter, and last until early spring or summer.^5,6

People affected by seasonal depression might experience:^5,6

• Persistent sadness
• Sleep disturbances
• Changes in appetite and unintentional weight changes
• Isolating from others or avoiding social activities

It’s important to recognize the signs that might signal seasonal depression and seek treatment when needed. Treatment for seasonal depressive disorder may include psychotherapy, light therapy, or antidepressant medication. Taking good care of your health and wellness through behavioral changes such as getting an adequate amount of sleep, exercising, eating a healthy diet, and staying connected to others can also help you cope with seasonal depression.⁶

Is Bipolar Disorder a Form of Depression?

Bipolar disorder (formerly called manic-depressive disorder) causes fluctuations in mood and energy and changes in one’s thoughts and behaviors. Bipolar disorder and depressive disorders are both types of mood disorders.

People with bipolar disorder experience a combination of manic episodes, where they feel incredibly happy and energetic, and depressive episodes which include depression symptoms such as a sad mood, hopelessness, and/or loss of joy or pleasure. Bipolar disorder can be different for different people and there are several types of the disorder.^1,7

How to Deal with Depression

One of the most important things you can do if you’re experiencing depression is seek treatment from a licensed professional such as a therapist, your primary care physician, or a psychiatric provider. A combination of therapy and medication is the most effective treatment for most people.⁹ In addition, the right coping skills can help anyone manage their depression while they wait to see a provider or in combination with treatment.

• Schedule activities: Plan activities in advance and holding yourself accountable to doing those actions can help mitigate feelings of depression. The items on your schedule can even be fun self-care tasks. ¹⁰
• Set small goals: The symptoms of depression can make even the smallest things, like brushing your teeth or taking a shower, seem overwhelming. Break tasks into smaller steps that feel manageable, follow through, and then celebrate your accomplishments.¹¹
• Stay connected: Isolation and loneliness can make depression worse. Even if you don’t feel like it, make it a point to reach out and spend time with the people you care about. Pets can also be a great source of support.¹²
• Make time for exercise: moving your body can help improve the symptoms of depression. Even just stretching or taking a walk around the block can make a difference.¹³
• Focus on nutrition: Studies show that what you eat impacts how you feel. Aim to include fruits, vegetables, protein, and whole grains in your diet and make sure you’re getting enough vitamin B12, iron, and fatty acids.⁴
• Get enough sleep: Depression can disrupt our sleep. It’s important to set a sleep routine and make an effort to stick to it, getting up and going to bed at the same times each day. Avoid screens, eating, and exercising right before bed.¹⁵

Treatment for Depression

Medication for Depression

Prescription antidepressant medication is one of the most common treatments for depression. Common prescription medications for depression include Selective Serotonin Reuptake Inhibitors, or SSRIs, and Serotonin and Norepinephrine Reuptake Inhibitors, or SNRIs.

About SSRIs and SNRIs

Serotonin and norepinephrine are two of the many neurotransmitters in the brain thought to have an effect on our mood.16 SSRI and SNRI antidepressant medications block the brain's process of reabsorbing these chemicals, helping to relieve depression symptoms. These medications:

• Take about 4-8 weeks for people taking them to feel the full effect of the medication but typically begin to provide relief of symptoms like fatigue, lethargy, sleep disturbances irritability, and poor concentration before mood improves
• Should be taken in the correct dose at the same time each day
• Work best when people don’t use alcohol or drugs at the same time
• Are not addictive and do not produce a “high”
• Usually only causes mild side effects that happen in the first several weeks of starting the medication and disappear very quickly¹⁶

Medication takes time to work and you may need to try several different types and amounts of medication to find what works best for you. Talk with your healthcare provider about your symptoms so that you can find the best course of treatment. In the unlikely event that an individual experiences significant side effects, there are often effective options to manage the side effects. Share any concerns related to medication side effects with your medication prescriber.

Treatment Resistant Depression

Treatment resistant depression represents a subset of people with major depressive disorder who do not experience an improvement in symptoms after adequate treatment. Many adults find relief from depression symptoms by taking oral antidepressants, starting talk therapy, and changing their lifestyle. For those taking medication who have tried multiple courses of antidepressants of adequate dosage and duration without a satisfactory reduction in symptoms, they may be considered to have Treatment Resistant Depression, or TRD, and should explore additional treatment options with their doctor. Individuals with TRD can experience improvement by leveraging strategies such as changing, augmenting, optimizing, or combining treatment types.^{17, 18}

Psychotherapy for Depression

Depression is treatable. Psychotherapy, often referred to as “talk therapy,” can help people understand and explain their depression, work through losses and traumas, and learn more helpful thinking techniques and positive self-beliefs.

Cognitive Behavioral Therapy, or CBT, is an effective evidence-based intervention often used to treat depression. CBT is based on understanding how cognitions, emotions, and behaviors interact with each other.^7,19 Specifically, CBT principles are rooted in the ideas that people suffering from psychological challenges like depression:

• Are experiencing unhelpful ways of thinking
• Have learned patterns of unhelpful behavior
• Can learn better ways of coping to relieve symptoms

A qualified therapist can use CBT techniques to help people with depression break the cycle of unhelpful thoughts, feelings, and behaviors.

Depression in Children and Adolescents

Depression in children and adolescents is common, but frequently unrecognized. While all youth will experience feelings of sadness from time to time, when these feelings become pervasive and last for 2 weeks or more, it may signal a more significant mental health concern¹. Depression can be diagnosed at any age, including young children, and the diagnosis becomes more prevalent during adolescence.

The diagnosis of depression for youth is based on the same criteria as adults, and some symptoms of depression are similar across ages¹:

• mood: feeling sad, irritable, or low for most of the day
• -energy: feeling tired, sluggish, tense or restless
• thoughts: worthlessness, guilt, or low self-esteem

Not all youth, however, will be able to report their mood symptoms or thoughts directly. In children and teens, additional symptoms of depression may include:

• Behaviors: acting out, being oppositional or disruptive at home and/or school
• School performance: dropping grades, difficulty focusing, attendance problems
• Eating: significant changes (up or down) in appetite or weight (not explained by normal growth/development, such as growth spurts or puberty)
• Social: withdrawal from family and/or friends, decreased interest or participation in sports, hobbies, and social activities, increased dependence on social media instead of other social activities
• Physical: frequent or repetitive complaints of physical symptoms like headaches or stomach aches, without identifiable cause
• Unsafe or risky behavior: substance abuse, self-injury, suicidal thoughts or behavior

Caregivers should discuss any concerns about their child’s mood, behaviors or possible depression symptoms with a healthcare provider. Early treatment of depression symptoms in youth decreases the likelihood that the symptoms will persist or become more severe. Any concerns about unsafe or risky behavior in a child or teen should be taken seriously and urgent evaluation by a healthcare professional is recommended.

Summary

Depression is a complex and pervasive mental health condition affecting millions of people worldwide. Its impact can be profound, influencing every aspect of daily life, from emotional well-being to physical health. Recognizing the symptoms and understanding the various forms of depression is crucial in seeking timely and effective treatment.

While depression can often feel overwhelming, it's important to remember that help is available. Whether through therapy, medication, or a combination of treatment there are numerous ways to manage and overcome depression. If you or someone you know is struggling, don't hesitate to seek help and take the first step toward recovery.