There are several types of depression. Doctors and therapists diagnose types of depression based on symptoms and duration. It is possible to be diagnosed with one type of depression and later receive a different diagnosis. It is also possible to have more than one form of depression simultaneously — sometimes known as “double depression.” Read more about how depression is diagnosed.
All forms of depression are treatable with psychotherapy, medications, or a combination of the two. Specific types of therapy and drugs are more beneficial for certain types of depression.
The most common type of depression, major depressive disorder (MDD) affects one out of every six people at some point in life. Everyone experiences depression differently, but most people with depression will see changes in their day-to-day functions and behavior. In order to be diagnosed with major depressive disorder, symptoms must persist for at least two weeks. When MDD is diagnosed, it is called clinical depression. Symptoms can range from mild (low mood) to severe (thoughts of self-harm).
Also known as dysthymic disorder or dysthymia, persistent depressive disorder is a form of depression that lasts for two or more years. A person with persistent depressive disorder may have periods of deep depression followed by milder symptoms. Diagnosis depends on symptoms that last for two years or more.
Sometimes referred to as major depressive disorder with psychotic features, psychotic depression is depression with psychosis. Psychosis may involve delusions and hallucinations. In psychotic depression, a person may have delusions that bad things are about to happen to them. The delusions often revolve around a theme — sickness, guilt, loss of money or possessions. Psychotic depression is a newer diagnosis and has not been researched as much as other forms of depression. As a result, it is often misdiagnosed.
Postpartum depression is one of the most common complications of childbirth. Postpartum depression, also called postnatal depression, affects as many as 15 percent of new mothers within a year of giving birth. Less commonly, postpartum depression can affect fathers and partners. Symptoms of depression, especially fatigue, anxiety, and low mood, can make it challenging for a person with postpartum depression to care for themselves and the baby. In addition, postpartum depression can disrupt the process of bonding with the baby, dull interest in the baby, and provoke thoughts of self-harm or harming the baby.
A rare form of postpartum depression is postpartum psychosis. Postpartum psychosis typically develops within the first two weeks after giving birth. As with psychotic depression, the new mother will experience hallucinations or delusions. She may feel very irritated, be paranoid or suspicious, or have rapid mood swings. Most women with postpartum psychosis will not be violent or destructive. However, irrational judgment or delusional thinking may lead to harmful actions. Postpartum psychosis should be treated as an emergency requiring immediate care and treatment.
Sometimes referred to as “winter depression,” seasonal affective disorder (SAD) is depression that occurs consistently during one period of the year, usually winter. Seasonal affective disorder takes longer to diagnose than clinical depression because diagnosis requires that a person have only experienced symptoms during the same season (winter or summer) for at least two years. It is thought that people with SAD are affected by the reduced levels of daylight between late autumn and spring. The farther away a person lives from the equator, the higher their risk for seasonal affective disorder. Women are four times as likely as men to suffer from SAD, and young people, including children and teenagers, are at a greater risk than older adults.
On top of common depression symptoms, SAD can cause food cravings and weight gain as well as oversleeping and social withdrawal — sometimes called hibernation — in the winter months. A smaller population experiences SAD during the summer, and their symptoms can include agitation, insomnia, and weight loss due to poor appetite.
Previously called manic depression, bipolar disorder is a mental illness that can cause extreme shifts in energy and mood. On the high end, a person will experience mania (more severe) or hypomania (less severe), which can make them feel hyperactive and unrealistically powerful or confident. During a manic episode, they may feel able to do riskier activities than they would do in a non-manic state. On the low end, a person with bipolar disorder will experience the same symptoms as those with other depressive conditions, but to an even more severe degree. In either state, psychosis is possible, and psychotic delusions or hallucinations tend to be in keeping with the high or low mood.
There are four subtypes of bipolar disorder:
Bipolar disorder affects males and females equally. Bipolar disorder is a lifelong condition that 1 percent of people experience. Bipolar disorder responds well to treatment. In addition to psychotherapy and mood stabilizers, antidepressants and antipsychotics may also be prescribed.
Some women experience severe and sometimes disabling psychological symptoms before their menstrual periods. Symptoms of PMDD include intense and disruptive mood changes that may include depression, anxiety, and irritability. Women with PMDD may also experience changes in sleeping or eating patterns. PMDD may be viewed as a severe type of premenstrual syndrome, or PMS.
When symptoms of depression occur within three months of a specific stressful event or life change, and the person has trouble coping with the distress the event has caused, they may be diagnosed with adjustment disorder with depressed mood. Adjustment disorder with depressed mood can impair a person’s normal functions and make it difficult to work, go to school, relate to loved ones, or complete daily tasks. In most cases, adjustment disorder with depressed mood is resolved within about six months.
Read more about treatments for depression and bipolar disorder.