Symptoms of depression typically develop gradually over days or weeks and can vary greatly. For example, an individual who is becoming depressed may appear sluggish and sad or irritable and anxious.
Many individuals with depression cannot experience emotions – including grief, joy, and pleasure – in a normal way. The world may appear to have become colourless and lifeless. They lose interest or pleasure in activities that they used to enjoy.
Depressed individuals may be preoccupied with intense feelings of guilt and self-denigration and may not be able to concentrate. They may experience feelings of despair, loneliness, and worthlessness. They are often indecisive and withdrawn, feel progressively helpless and hopeless, and think about death and suicide.
Most depressed individuals have difficulty falling asleep and awaken repeatedly, particularly early in the morning. Some individuals with depression sleep more than usual.
Poor appetite and weight loss may lead to emaciation, and in women, menstrual periods may stop. However, overeating and weight gain are common in individuals with mild depression.
Some depressed individuals neglect personal hygiene or even their children, other loved ones, or pets. Some complain of having a physical illness, with various aches and pains.
The term depression is used to describe several related disorders:
- Major depressive disorder;
- Persistent depressive disorder; and
- Premenstrual dysphoric disorder.
Major Depressive Disorder
Individuals with major depressive disorder are depressed most days for at least 2 weeks.
- They may appear miserable.
- Their eyes may be full of tears, their brows may be furrowed, and the corners of the mouth may be turned down.
- They may slump and avoid eye contact.
- They may hardly move, show little facial expression, and speak in a monotone.
Persistent Depressive Disorder
Individuals with persistent depressive disorder have been depressed for most of the time for 2 years or more.
Symptoms begin gradually, often during adolescence, and may last for years or decades.
How many symptoms are present at one time varies, and sometimes symptoms are less severe than those in major depression.
- Individuals with this disorder may be gloomy, pessimistic, sceptical, humourless, and incapable of having fun.
- Some are passive, lack energy, and keep to themselves.
- Some constantly complain and are quick to criticise others and reproach themselves.
- They may be preoccupied with inadequacy, failure, and negative events, sometimes to the point of morbid enjoyment of their own failures.
Premenstrual Dysphoric Disorder
Severe symptoms occur before most menstrual periods and disappear after they end.
Symptoms cause substantial distress and/or greatly interfere with functioning.
Symptoms are similar to those of premenstrual syndrome but are more severe, causing great distress and interfering with functioning at work and social interactions.
Premenstrual dysphoric disorder may first appear any time after girls start to menstruate. It may worsen as women approach menopause but ends after menopause.
It occurs in about 2 to 6% of women who are menstruating.
- Women have mood swings, suddenly becoming sad and tearful.
- They are irritable and anger easily.
- They feel very depressed, hopeless, anxious, and on edge.
- They may feel overwhelmed or out of control.
- They often put themselves down.
As with other types of depression, women with this disorder may lose interest in their usual activities, have difficulty concentrating, and feel tired and without energy.
They may eat too much and crave certain foods.
They may sleep too little or too much.
Like many women whose period is about to start, these women may have tender, swollen breasts and/or achy muscles and joints.
They may feel bloated and gain weight.
Medical professionals use certain terms to describe specific symptoms that can occur in people with depression. These terms include:
- Anxious distress:
- Individuals feel tense and unusually restless.
- They have difficulty concentrating because they worry or fear that something awful may happen or that they may lose control of themselves.
- Individuals also have three or more symptoms of mania.
- These symptoms include feeling exuberant and/or overly confident, talking more than usual, sleeping little, and racing thoughts.
- These individuals do not have all the symptoms required for a diagnosis of bipolar disorder, but they are at risk of developing it.
- Individuals no longer take pleasure in any activities they used to enjoy.
- They appear sluggish, sad, and despondent.
- They speak little, stop eating, and lose weight.
- They may feel excessively or inappropriately guilty.
- They often awake early in the morning and cannot go back to sleep.
- Individuals may temporarily cheer up when something good happens, such as a visit from their children.
- They have an increased appetite, resulting in weight gain.
- They may sleep for long periods of time.
- They are excessively sensitive to perceived criticism or rejection.
- They may feel weighted down, as if they can hardly move their legs.
- Individuals have false beliefs (delusions), often of having committed unpardonable sins or crimes, of having incurable or shameful disorders, or of being watched or persecuted.
- Individuals may have hallucinations, usually of voices accusing them of various misdeeds or condemning them to death.
- Individuals are very withdrawn.
- Thinking, speech, and general activity may slow down so much that all voluntary activities stop.
- Some individuals mimic others’ speech (echolalia) or movements (echopraxia).
- Episodes of depression occur every year at a particular time of year, usually starting in the autumn/fall or winter and ending in the spring.
- These episodes are more common in extreme northern and southern latitudes, where the winter season is typically longer and harsher.
- Individuals are sluggish.
- They lose interest in and withdraw from their usual activities.
- They may also sleep too much and overeat.
Thoughts of death are among the most serious symptoms of depression. Many depressed individuals want to die or feel they are so worthless that they should die. As many as 15% of untreated depressed individuals end their life by suicide.
A suicide threat is an emergency. When individuals threaten to kill themselves, a medical professional(s) may hospitalise them so that they can be supervised until treatment reduces the risk of suicide. The risk is especially high in the following situations:
- When depression is not treated or is inadequately treated.
- When treatment is started.
- When individuals are becoming more active mentally and physically but their mood is still dark).
- When Individuals have a significant anniversary.
- When individuals alternate between depression and mania (bipolar disorder).
- When individuals feel very anxious.
- When individuals are drinking alcohol or taking recreational or illicit drugs.
- In the weeks to months after individuals have attempted suicide, particularly if they used a violent method.
Individuals with depression are more likely to abuse alcohol or other recreational drugs in an attempt to help them sleep or feel less anxious.
However, depression leads to alcoholism and drug abuse less often than was once thought.
Individuals are also more likely to smoke heavily and to neglect their health.
Thus, the risk of developing or worsening other disorders, such as chronic obstructive pulmonary disease, is increased.
Other Effects of Depression
Depression may reduce the immune system’s ability to respond to foreign or dangerous invaders, such as microorganisms or cancer cells.
As a result, individuals with depression may be more likely to get infections.
Depression increases the risk of heart and blood vessel disorders (such as heart attacks) and stroke.
The reason may be that depression causes certain physical changes that increase this risk.
For example, the body produces more of the substances that help blood clot (clotting factors), and the heart is less able to change how fast it beats in response to different situations.