According to the National Institute of Mental Health and few other associations there are several types of depression.
Major Depressive Disorder or Major Depression – This is characterized by combination of symptoms that interfere with an individual’s ability to work, sleep, study, eat, and enjoy once-pleasurable activities. Major depression is disabling and prevents a person from functioning normally. Some people may experience only a single episode within their lifetime, but more often a person may have multiple episodes.
If you’re experiencing major depression, you may feel and see symptoms of extreme sadness, hopelessness, lack of energy, irritability, trouble concentrating, changes in sleep or eating habits, feelings of guilt, physical pain, and thoughts of death or suicide — and for an official diagnosis, your symptoms must last for more than two weeks.
Dysthymic disorder, or dysthymia – It is characterized by long-term (two years or longer) symptoms that may not be severe enough to disable a person but can prevent normal functioning or feeling well. People with dysthymia may also experience one or more episodes of major depression during their lifetimes. Person can function adequately, but not optimally. Symptoms include sadness, trouble concentrating, fatigue, and changes in sleep habits and appetite.
Minor depression is characterized by having symptoms for two weeks or longer that do not meet full criteria for major depression. Without treatment, people with minor depression are at high risk for developing major depressive disorder.
Some forms of depression are slightly different, or they may develop under unique circumstances. They include:
- Psychotic depression – which occurs when a person has severe depression plus some form of psychosis, such as having disturbing false beliefs or a break with reality (delusions), or hearing or seeing upsetting things that others cannot hear or see (hallucinations).
- Postpartum depression – which is much more serious than the “baby blues” that many women experience after giving birth, when hormonal and physical changes and the new responsibility of caring for a newborn can be overwhelming. It is characterized by feelings of extreme sadness, fatigue, loneliness, hopelessness, suicidal thoughts, fears about hurting the baby, and feelings of disconnect from the child. It can occur anywhere from weeks to months after childbirth.
- Seasonal affective disorder (SAD) – which is characterized by the onset of depression during the winter months, when there is less natural sunlight. SAD is characterized by symptoms of anxiety, increased irritability, daytime fatigue, and weight gain. This form of depression typically occurs in winter climates, likely due to the lessening of natural sunlight. The depression generally lifts during spring and summer.
Premenstrual Dysphoric Disorder – Premenstrual dysphoric disorder, or PMDD, is a type of depression that affects women during the second half of their menstrual cycles. Premenstrual dysphoric disorder (PMDD) is a severe form of premenstrual syndrome (PMS).
Emotional symptoms are generally present, and in PMDD, mood symptoms are dominant. Anxiety, anger, and depression may also occur. The main symptoms, which can be disabling, include feelings of deep sadness or despair; feelings of intense tension or anxiety; increased intense sensitivity to rejection or criticism; panic attacks; rapid and severe mood swings, bouts of uncontrollable crying; lasting irritability or anger; increased interpersonal conflicts; disinterest in daily activities and relationships; difficulty concentrating; chronic fatigue; food cravings or binge eating; insomnia or hypersomnia; feeling overwhelmed or feelings of being out of control; increase or decrease in sex drive; increased need for emotional closeness.
Common physical symptoms include: Breast tenderness or swelling, heart palpitations, headaches, joint or muscle pain, swollen face and nose; an altered view of one’s body, sensation of bloating, feeling fat or actual weight gain. Five or more of the above symptoms may indicate PMDD.