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Depressive Episode

Written by Ada’s Medical Knowledge Team

Updated on

What is a depressive episode?

The definition of a depressive episode is a period of depression that persists for at least two weeks. 1 During a depressive episode, a person will typically experience low or depressed mood and/or loss of interest in most activities, as well as a number of other symptoms of depression, such as tiredness, changes in appetite, feelings of worthlessness and recurrent thoughts of death. The length of a depressive episode varies, but the average duration is thought to be six to eight months. 2

Depression is a common illness, and many people will experience one or more episodes of depression in their lifetime. While people of all races and ages can experience depressive episodes, they tend to be more common among women than men. 3 4 People who have a history of depression, other mental health conditions such as bipolar disorder or anxiety, or chronic physical conditions such as diabetes, chronic pain or multiple sclerosis 5, also have a higher risk of experiencing a depressive episode. 2

The severity of a depressive episode varies; it may be classified as major or minor, depending on the number of symptoms and degree of impairment (social, domestic and work) experienced. 6 Regardless of the severity, all depressive episodes should be taken seriously and treated promptly by a professional healthcare provider. 7 Effective treatment, which typically involves medication and/or therapy, for depression is available. 4

Without appropriate treatment, the risk of experiencing further episodes of depression is thought to be higher. The risk of another depressive episode occurring seems to increase with every new episode, with each one likely to last longer and be more severe than the previous one. Timely treatment can alleviate the symptoms of depression and help shorten the duration of any future episodes. 8

Depressive episode symptoms

The symptoms of a depressive episode typically include a depressed mood, i.e. feeling sad, empty or hopeless, and/or loss of interest or enjoyment in most activities, together with any number of the following: 1 9

  • Feeling worthless or excessively guilty
  • Fatigue or lethargy
  • Difficulty with concentration, memory and decision-making
  • Insomnia, not being able to sleep through the night, waking up early or sleeping too much
  • Appetite changes
  • Unexplained weight loss or gain
  • Unexplained physical ailments that do not respond to treatment, such as headaches, digestive problems or pain
  • Sluggishness, restlessness, agitation or irritability
  • Thoughts of death or suicide, sometimes with suicide plans or suicide attempts

These symptoms are usually present every day or almost every day, for at least two weeks. 1

Signs of depression may differ according to sex and age. There are also various types of depression and depressive disorders, including major depression, bipolar disorder (previously known as manic depression), postpartum depression and dysthymia, among others. 10

If a person seems to be in imminent danger of harming themselves, an emergency support provider should be contacted immediately.

Causes of a depressive episode

The causes of depressive episodes are complex and varied, involving social, psychological and biological factors. Depression may occur as an isolated episode or as part of a chronic depressive condition. 4 While the exact causes are not yet fully understood, the following may increase a person’s likelihood of experiencing a depressive episode: 2 3 ref7 11 12

  • History of depressive episodes
  • Bipolar disorder
  • Anxiety
  • Attention-deficit hyperactivity disorder (ADHD)
  • Other mental health conditions
  • Family history of depression
  • Changes in the functioning of the brain
  • History of sleep problems
  • Chronic pain
  • Heart disease, cancer and other chronic health conditions
  • Stressful life events such as losing one’s job, losing a loved one (bereavement) or psychological trauma
  • Lack of personal support structures
  • Drug and alcohol abuse
  • Childhood trauma

People who have recently had a baby may experience postpartum depression. 13

Sometimes, there is no obvious cause for the occurence of a depressive episode. 12

Some health conditions, such as hypothyroidism, can cause symptoms of depression. 3 While uncommon, adverse reactions to certain medications can also cause depressed mood. 2 However, treating these underlying causes and disorders should alleviate the symptoms.

Diagnosis of a depressive episode

After taking the affected person’s medical history and performing a physical examination, a doctor or the mental health specialist to which the person is referred to, can diagnose a depressive episode based on the criteria set out in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5).

A major depressive episode (MDE) is characterized by five or more of the following symptoms being present every day, or almost every day, for a minimum of two weeks: 1

  • Depressed mood for most of the day
  • Loss of interest or enjoyment in all or most activities
  • Significant unexplained weight loss or gain, or appetite changes
  • Sleep disturbances, including insomnia or sleeping too much (hypersomnia)
  • Restlessness or sluggishness
  • Tiredness or lack of energy
  • Feelings of worthlessness or excessive guilt
  • Difficulty thinking, concentrating or making decisions
  • Thoughts of death or suicide – there may be suicide plans or suicide attempts

These symptoms should indicate a marked difference from the affected person’s previous functioning. For the diagnosis to be made, at least one of the symptoms needs to be depressed mood or loss of interest in most activities. It is also necessary for the symptoms to cause significant distress or impairment in social and job functioning. 1

If the symptoms are attributed to another mental health condition, the diagnosis and treatment may be different to that detailed here for a depressive episode. 1

To rule out any other health conditions that could be causing symptoms of a depressive state, such as a thyroid disorder, a doctor may order blood tests or scans. If a person is considered to be at risk of dementia, the doctor will also check for this condition, as some of the symptoms can be similar to depression. 2

Minor depressive episode

If only two to four of the above symptoms are present, instead of major depressive episode, a diagnosis of minor depressive episode may be made. At least one of the symptoms needs to be depressed mood or loss of interest in most activities. 14 This may occur as part of a minor depressive disorder.

Depressive episode treatment

Depression is considered to be a treatable condition, with treatment often involving a combination of medication and therapy. Sometimes complementary remedies and lifestyle changes may also be suggested. The treatment program will be tailored according to the severity of the depressive episode, as well as the affected person’s medical history and personal preferences. 2 3 13


Psychotherapy is talk therapy, and there are several different types that may be effective for people experiencing a mild or moderate depressive episode. These include counseling, problem-solving therapy, interpersonal therapy, group therapy and cognitive behavioral therapy (CBT) – which can help a person develop more helpful ways of thinking and acting. 12 15

For some people, a combination of psychotherapy and medication may be more effective than psychotherapy alone for depression. 15


Medication may be prescribed in cases of moderate or severe depression, often in combination with a course of psychotherapy. 2 While the way it works is not yet fully understood, antidepressant medication may alter the levels of neurotransmitters in the brain with a positive impact on mood. 12 15

Several different types of antidepressants are available. The main categories include: 15 16

  • Selective serotonin reuptake inhibitors (SSRIs): Typically the first line of treatment, 2 SSRIs tend to cause fewer side-effects than other antidepressants. Examples of SSRIs include fluoxetine, paroxetine and sertraline.
  • Serotonin and norepinephrine reuptake inhibitors (SNRIs): Similar to SSRIs, but may work better for some people. Examples include venlafaxine and duloxetine.
  • Tricyclic antidepressants (TCAs): An older type of medication that may cause more side-effects. Generally only prescribed if other treatments do not work, or for other mental health conditions. Examples of TCAs include amitriptyline and imipramine.
  • Monoamine oxidase inhibitors (MAOIs): A type of antidepressant usually prescribed when other treatments have not worked or have caused intolerable side-effects, as well as in cases of atypical depression, which has different characteristics to other types of depression. Examples include phenelzine and isocarboxazid. Because MAOIs can interact with certain foods and medications, special care must be taken with this antidepressant. 17

There are also a few other types of antidepressants, such as bupropion and mirtazapine.

It may take a few weeks for an antidepressant to take effect and alleviate the symptoms of a depressive episode. A doctor will advise on how long the medication should be taken and what to do if a person wishes to stop taking it. While antidepressants are not considered to be addictive, stopping them suddenly may cause discontinuation symptoms, so the process needs to be managed by a medical practitioner. 15

Some people may experience side-effects while taking antidepressants, including: 15

  • Nausea and vomiting
  • Weight gain
  • Diarrhea or constipation
  • Feeling sleepy
  • Sexual problems

While less common, other side-effects may include serotonin syndrome, a potentially life-threatening condition where high levels of serotonin cause mental and physical symptoms like anxiety, rapid heartbeat, high temperature and vomiting, 18 and suicidal thoughts. 15

It may be necessary for a person to try several different medications before finding one that they feel works for them. 15 The type of antidepressants prescribed will depend on the affected person’s age, health and medical history. A doctor will arrange check-ups a couple of weeks after treatment is started and regularly thereafter to monitor progress. 2

Other remedies

Exercise: Physical activity may be recommended to help with mild to moderate depression, though it is not entirely clear how effective exercise is. 2 3

St John’s Wort: This herbal medicine is sometimes recommended for depressive episodes. However, its efficacy has not been conclusively proven, and it may interact with prescription medications. Prior to taking St John’s Wort, it is advisable to consult a doctor even if taking no other medications, but especially if taking other prescription or over-the-counter medication. 12 15

Electroconvulsive therapy (ECT): In this treatment, electrical current is used to stimulate the brain. ECT is typically reserved for depression that is particularly severe or has not responded to other treatments. 12

Light therapy: Bright light therapy has been shown to improve depressive symptoms, both as part of seasonal affective disorder (SAD) and non-seasonal major depressive disorder. Light therapy may be helpful on its own or in combination with psychotherapy or antidepressant medication. 19

Acupuncture, spiritual practice and nutritional changes may also be suggested as complementary therapies to help in the treatment of depressive episodes, though there is insufficient scientific evidence to support their efficacy. 3

If the depressive episode is mild, a doctor may suggest waiting for two weeks to see if it clears on its own. In addition, they may recommend self-help resources, relaxation therapies and a small number of psychotherapy sessions. Antidepressants are not usually prescribed for mild depression unless it persists or is causing complications. 2 13

In severe cases of depression, where a person is at risk of harming themselves or others, or is experiencing psychotic symptoms, they may be referred to a specialist care facility. 2

If a person seems in imminent danger of harming themselves, an emergency support provider should be contacted immediately.

Prevention of depressive episodes

Speaking to a healthcare professional and following the treatment program they recommend is very important in managing depressive episodes.

While there is no known way to prevent a depressive episode, certain positive behaviors may be helpful. These include: 12

  • Talking about feelings when upset
  • Staying active, e.g. exercising and getting outdoors
  • Eating a balanced diet
  • Avoiding alcohol and drugs
  • Writing down factors that may be causing the depression and trying to find solutions

Depressive episode FAQs

Q: I feel a depressive episode coming on. What can I do to stop it?
A: If you think that you are about to experience a depression flare-up, it is recommended that you speak to a psychotherapist or other qualified healthcare professional. If this is not possible, an online or over-the-phone counseling service may be helpful. See numbers for mental health helplines in the UK and USA and crisis lines in other countries. There is currently no known way to prevent a depressive “attack”, but therapy and/or antidepressant medication may help to manage it. In addition, practicing self-care is recommended. This includes talking about your feelings if you are upset, getting regular exercise, getting outdoors, eating a balanced diet and avoiding alcohol and other intoxicating substances.

Q: How long does a depressive episode last?
A: The duration of a depressive episode varies and is influenced by its severity, as well as treatment and individual factors. However, the average length of a depressive episode is thought to be six to eight months. 2

Q: What should I do during a depressive episode?
A: When depression “hits”, many people wonder what they can do to get out of the depressed state. There is no quick remedy for a depressive episode, but it is important to remember that you can take steps to manage it, beginning by speaking to a doctor or psychotherapist, and/or taking antidepressant medication. In addition, practising self-care strategies like getting exercise, eating healthily and avoiding alcohol and drugs is recommended.

Q: If a loved one is experiencing a depressive episode, what is the best thing to do?
A: If a friend or partner shows signs of being depressed, the following behaviors may be helpful: 12

  • Listening without judgment
  • Spending time with the person
  • Reassuring them that they can get better
  • Helping them to eat a balanced diet
  • Helping them get outside and moving, e.g. by taking them on regular walks or supporting them exercising
  • Helping them to avoid alcohol
  • Encouraging them to speak to a healthcare professional
  • Encouraging them to adhere to their treatment program

It is important to understand that it may take a person experiencing depression a long time to get better. The support of family, friends and broader social networks is an important part of recovery.

Associated terms used for depressive episodes

  • Major Depression
  • Depression
  • Mild Depression
  • Dysthymia
  • Chronic depression
  • Dysthymic Disorder
  • Neurotic depression
  • Persistent depressive disorder
  • Affective disorder
  • Mood disorder