Double depression can develop in the context of persistent depressive disorder (PDD), formerly known as dysthymia. It is an informal term used to describe persistent depressive disorder and major depressive disorder occurring at the same time. The condition usually starts as persistent depressive disorder (PDD) and becomes double depression when a person with PDD also develops major depressive disorder (MDD). Double depression is a form of depression that can significantly affect your quality of life and daily functioning. People with this condition may be more likely to develop diabetes, heart disorders, and engage in substance abuse than those dealing with other forms of depression. It is less common than other forms of depression but is a condition which left untreated may result in severe complications. To understand double depression properly you must first take a look at the two major components of the condition. 

Persistent Depressive Disorder (PDD)

Persistent depressive disorder is a low-grade form of depression. When a person has been depressed for at least two years and exhibits some of the following symptoms, a diagnosis of PDD can typically be made:

Loss of appetite FatigueLow self-esteem Insomnia or sleeping excessively Avoiding social activities Getting easily irritated or angered 

In children or adolescents, these symptoms should have persisted for at least one year before a diagnosis of PDD can be made.  People with PDD often report feeling like they are covered by a veil of darkness or a deep fog. When left untreated, PDD can sometimes persist for decades.

Major Depressive Disorder (MDD)

Major depressive disorder tends to be an episodic form of depression. It is characterized by intense and recurring feelings of sadness and hopelessness, loss of interest in activities and accompanied by a variety of cognitive and physical symptoms. Some of the symptoms of this particular form of depression include: 

Insomnia or sleeping excessively Loss of energy Difficulty focusingFatigue or agitationSuicidal thoughts 

People with non-chronic major depression might experience periods that are free of any depressive symptoms.

Diagnosis 

There are no specific tests to diagnose double depression. Your doctor will take a detailed history of your mood symptoms to see whether you have met criteria for dysthymia and whether you now meet criteria for major depressive disorder. There is currently no criteria for diagnosing double depression in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Diagnosis is typically made by using both the DSM-5 criteria for diagnosing MDD and PDD. Because there is no specific criteria for diagnosing double depression, it often goes unrecognized and can be harder to treat than MDD or PDD alone.

Causes 

There is no clear cause of double depression. A combination of genetic and environmental factors might be responsible for the condition developing. Environmental factors that might trigger the condition include unemployment, major life changes, substance abuse, and trauma. 

Treatment 

A combination of medication and therapy is typically used to treat double depression. The focus of treatment for double depression is alleviating the more acute symptoms of your major depression and addressing the more chronic issues related to your persistent depressive disorder. Your doctor is most likely to tailor your treatment plan to your specific need.

Medication 

There are many medication options for treating symptoms of depression. The medication available for treating depression is usually similar across the different types of depression. They typically include antidepressants such as selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs). Most people won’t notice the effect of medication on their depressive symptoms right away. It can take a couple of weeks and in some cases a couple of months to see the desired results.

Therapy 

Cognitive-behavioral therapy is most commonly used when treating double depression. This form of therapy focuses on helping you recognize distorted thought processes, beliefs, and behaviors that are contributing to your depression, and helping you challenge these. It helps a person with double depression to see themselves in new ways and cope with their depressive symptoms better. However, for therapy to be most effective, a combination of medication and therapy is often needed.

Coping 

Double depression can be a difficult condition to live with but it doesn’t have to be a debilitating one. With the right treatment and care, the depressive symptoms characterized by this condition can be treated. In addition to the treatment recommended by your doctor, there are also certain coping mechanisms you can adopt. Making healthier lifestyle choices such as exercising and eating properly and more optimally managing stressors in your life like your job, can significantly improve your depressive symptoms. Appropriate treatment and coping skills can also help prevent relapse and recurrence in double depression.