What Is Depression?

Depression also referred to as major depressive disorder or clinical depression is a mental disorder characterized by at least two weeks of persistent low mood and loss of interest in the usual enjoyable day-to-day activities. It can decrease an individual’s ability to function properly at home and work and lead to various emotional and, in some cases, also physical problems. For an individual to be diagnosed with depression, symptoms must persist at least for two weeks and be serious enough to interfere with their social life, home life, and work.

Often, this disorder develops gradually. That is why it might be difficult to identify depression. Many individuals try to cope with depression symptoms by themselves without realizing they have a mental disorder. In many cases, it is a friend or family member who notices something is wrong and recognizes their loved one needs a professional's help. The severity of depression depends on how much it impacts a person's daily life. Besides, some medical conditions (e.g., thyroid problems, vitamin deficiency, or a brain tumor) can mimic depression symptoms, so it is crucial to rule them out.

If you think you or someone you know might be at risk for or already suffering from depression, we suggest you take this reliable and free Beck's Depression Inventory. Please bear in mind this test is just an assessment tool and not an official diagnosis. Only a licensed medical professional can make a diagnosis.

Depression Symptoms

Depression may occur only once in a lifetime. In fact, according to recent research, one in six people experience depression at some point in their life. However, most individuals usually have multiple episodes of the disorder. During these episodes, symptoms occur almost daily and last most of the day.

Symptoms of depression can be psychological, physical, and social. Here below, we will list the most common ones.

Psychological Symptoms

Psychological depression symptoms typically include most or all of the following:

  • Feelings of hopelessness, helplessness, emptiness, and continuous sad mood;
  • Low self-esteem;
  • Constant anxiety and worry;
  • Frustration, irritability, angry outbursts, even over little things;
  • Loss of motivation, interest, and pleasure in most or all normal activities once enjoyed, like hobbies, sports, or even sex;
  • Having a hard time making decisions;
  • Self-harm and/or suicidal thoughts.

Physical Symptoms

Physical depression symptoms usually include as follows:

  • Reduced appetite and weight loss or, on the contrary, increased food cravings and weight gain;
  • Increased fatigue, tiredness, and lack of energy, so even minor tasks take extra effort;
  • Decreased sex drive and/or loss of libido;
  • Speaking or moving more slowly than usual;
  • Unexplained pains and aches;
  • In women, changes to the menstrual cycle;
  • Sleep disturbances - difficulty falling/staying asleep or, on the contrary, sleeping too much.

Social Symptoms

Some of the most common social symptoms of depression include:

  • Poor performance at work;
  • Unwillingness to take part in social activities, avoiding friends;
  • Neglecting interests and hobbies;
  • Having difficulties in relationships and family life.

Depression Treatments

Even though there is no cure for depression, patients have plenty of options for treatment. In fact, depression is one of the most treatable mental health conditions. At least 80% of individuals suffering from depression eventually respond well to treatment. Almost all patients notice after a while that medication, therapy, or the combination of these two have minimized the impact of depression symptoms on their daily life.



Psychotherapy for depression can take many forms, including the following:

  • Cognitive behavioral therapy (CBT): focuses on working with the patient to uncover unhealthy thought patterns and identify how they might be causing negative beliefs and harmful behaviors;
  • Mindfulness-based cognitive therapy (MBCT): this type of therapy combines the ideas of cognitive therapy with meditation practices based on the cultivation of mindfulness;
  • Interpersonal therapy (IPT): addresses interpersonal issues and puts emphasis on the way symptoms are related to an individual's relationships with family and peers.


Antidepressants may produce some improvement within the first two weeks of use. However, full benefits may be seen only after two to three months of treatment. If a patient feels no improvement after several months, their doctor can alter the dose of the medication or substitute it with another. It is usually recommended that people suffering from depression continue to take medication for approximately six months after the symptoms have reduced.

Electroconvulsive Therapy (ECT)

Electroconvulsive therapy is commonly reserved for individuals with severe major depression who have not responded to other treatments. ECT involves a brief electrical stimulation of the brain while the patient is under anesthesia, and is managed by a team of trained medical professionals including a psychiatrist, an anesthesiologist, and a nurse. A person who has severe depression usually receives ECT two to three times a week for a total of six to twelve treatments.

Can Depression Relapse Be Prevented?

Once an individual has had an episode of clinical depression, they are at high risk of having another. The best way to prevent another episode of depression is to be aware of the triggers and causes of the disorder and to continue taking the prescribed medications.

Here are some tips that may be useful to people who want to prevent depression relapse:


  • Regular exercise;
  • Practicing mindfulness and meditation;
  • Reducing stress by avoiding overcommitting to things and letting go of things that one cannot control.

Depression Vs. Grief

Sometimes it is difficult to know the difference between grief and depression. Both conditions are similar, but there are differences. Grief is a natural response to the loss of a loved one, while clinical depression is a disorder. When an individual is grieving, they find that the feeling of sadness comes and goes. But they are still able to enjoy things and look forward to the future. If someone has clinical depression, they feel sad most of the time. They do not enjoy anything in their life and are very negative about the future.

Also, when someone is grieving, they maintain their self-esteem. And if an individual has depression, they usually experience feelings of self-loathing and worthlessness. In some cases, grief and clinical depression can co-occur. For some individuals, losing a job or a loved one, being a victim of an assault can cause them depression. When depression and grief co-exist, the latter is more severe and lasts much longer than just grief. It is essential to determine whether a person is suffering from depression or grieving. It will help them get the correct treatment or support they need.

Risk Factors for Depression

It is important to know what factors can increase an individual’s risk for depression. It may help you (or your loved ones) get the best medical care if and when needed. Here are some of the most common depression risk factors:

  • Family history: it is believed that the condition may run in families; for instance, if one of the identical twins has been diagnosed with depression, the other has a 70% chance of experiencing the disorder at some point in their life.
  • Personality: individuals with “naturally” low self-esteem and those who are generally pessimistic are usually more likely to have depression.
  • Loss of a loved one: as mentioned before, grief can grow into depression in some people; those who are easily overwhelmed by stress are particularly vulnerable to this disorder.
  • Stressful life events: divorce, major illness or injury, loss of employment and/or income may cause some people depression. Note that in some cases, even things considered positive by most, like graduation, moving to a new home, marriage, or having a baby, may make an individual depressed.
  • Substance abuse: about 30% of individuals who abuse alcohol or drugs also suffer from depression.
  • Environmental factors: continuous exposure to emotional, sexual, or physical abuse, neglect, or extreme poverty may make some individuals more vulnerable to the condition.
  • Biochemistry: insufficient specific chemical substances (neurotransmitters) in the brain may contribute to depression.
  • Other mental illnesses: sometimes depression can be a reaction to (or pair with) another mental health condition, for example, anxiety disorder or ADHD.

Depression Symptoms in Teenagers

Common signs of depression in adolescents are similar to those in adults, but there can be some additional symptoms. Such symptoms in teenagers may include:

  • Poor attendance and/or poor performance at school;
  • Extreme sensitivity to failure;
  • The need for excessive reassurance;
  • Feeling misunderstood by parents and/or siblings;
  • Less attention to appearance and personal hygiene;
  • Repeated thoughts that life is harsh and the future is hopeless;
  • Recurring thoughts and ideas about death and/or suicide, or a suicide attempt.

Depression Symptoms in Older Adults

Sadly, depression often goes undiagnosed and untreated in older people because of the common belief that depression is a normal part of aging. It is also true that, in comparison with people of other age groups, seniors may feel more reluctant to seek help or be less willing to take their medications because of fear of side effects or cost.

It is essential to know that older adults are at an increased risk of experiencing the disorder. According to numerous research, about 80% of the elderly have at least one chronic disease, and approximately half of the older adults have two or more chronic health conditions. Some of them may have disabling or life-threatening medical conditions, such as diabetes or cancer. And that is a huge risk factor for depression.

Seniors may also be isolated and have just a few people around, which itself may lead to depression. That is another major risk factor for developing the disorder.

Often, older adults display depression symptoms in a different manner compared to individuals of other age groups. That is why it is so important to know how the elderly manifest these signs and symptoms. Here are some of them:

  • Sudden changes in appetite;
  • Restlessness;
  • Withdrawal;
  • Physical pain that cannot be explained by other medical conditions.

Treatment of depression in seniors typically involves a combination of lifestyle changes, psychotherapy, and medications, like tricyclic antidepressants, monoamine oxidase inhibitors (MAOIs),selective serotonin reuptake inhibitors (SSRIs),and selective serotonin-norepinephrine reuptake inhibitors (SNRIs).

Other Types of Depression

In addition to major depression, there are several other types of depression. Here below, we will describe some of them.

Postpartum Depression

Postpartum depression

Postpartum (also referred to as postnatal) depression is the term used to describe the type of depression that 10% to 15% of new moms experience in the first year after giving birth to their baby. Some symptoms of this disorder include feeling sad, tearful, anxious, and lonely. A woman suffering from postpartum depression may also be constantly worrying too much about her baby, feeling guilty, agitated, or angry, experiencing panic attacks, and/or having difficulty sleeping. Symptoms of this disorder may take some time to develop and are usually most noticeable when the infant is 4 to 6 months old. Usually, this condition is treated similarly to other kinds of depression, including talking therapy and antidepressant medications. Usually, the disorder lasts for about three months. However, if not treated, postnatal depression may last much longer than that.

Seasonal Affective Disorder

Seasonal Affective Disorder (SAD),sometimes colloquially referred to as winter depression, is a period of depression that often occurs during the winter months when it is cold and people get less sunlight. It may happen even in people who have perfectly normal mental health throughout the rest of the year. As a matter of fact, SAD typically goes away in the spring and summer. The most common symptoms of the disorder may include persistent low mood, decreased sex drive, difficulty concentrating, feeling lacking in energy, sleeping too much, craving carbohydrates, and/or overeating. For some individuals, these symptoms can be mild, and for others, more severe.

Antidepressants and therapy can help if a person has severe SAD. Sitting in front of a bright light box for 15-30 minutes a day may be helpful too.

Psychotic Depression

Individuals with psychotic depression manifest the symptoms of major depression along with the following psychotic symptoms:

  • Delusions (false beliefs);
  • Paranoia (a person wrongly believing that other people are trying to hurt them);
  • Hallucinations (hearing, seeing, tasting, or feeling things that appear to be real but in actuality only exist in an individual’s mind).

Antidepressant and antipsychotic drugs can be good options to help treat psychotic depression.


In recent years, many advancements have been made in medical science regarding depression. Still, more research is necessary on this condition. By finding accurate root causes of the disorder, treatment options can start to get to the base of the issue, which may lead to better treatment plans. That will definitely mean a lot for future generations affected by depression.


Kessler, R. C. The costs of depression. Psychiatr. Clin. N. Am. 35, 1–14 (2012). ScienceDirect

Grossberg A., Rice T. Depression and Suicidal Behavior in Adolescents. Medical Clinics of North America, 2022. ScienceDirect

Campayo, A., Gómez-Biel, C. H. & Lobo, A. Diabetes and depression. Curr Psychiatry Rep. 13, 26–30 (2011). PubMed

Krebber, A. M. H. et al. Prevalence of depression in cancer patients: A meta-analysis of diagnostic interviews and self-report instruments. Psychooncology 23, 121–130 (2014). PubMed