Persistent depressive disorder is a newly coined term in the DSM-5 to capture what was originally known as dysthymia and chronic major depression.  This disorder has been poorly understood, and its classification has evolved due to the complicated and ever-evolving nature of the nosology of depressive disorders.  In the past, this disease was considered a depressed personality state, but it is likely better conceptualized as a disease state rather than a personality disorder (permanent, pervasive way of approaching the world).  This change is reflected in the history of the diagnosis as the DSM-II originally identified it as a personality disorder.  It was not until the DSM-III that dysthymic disorder was defined as a mild chronic depression lasting longer than 2 years.[2]  The origin of the word dysthymia dates back to its Greek roots, with the first use of the word referring to psychiatry occurring by CF Fleming around 1844.

Worldwide it is estimated the prevalence of depression (including persistent depressive disorder/dysthymia) is approximately 12%.  In the United States, the prevalence is slightly higher, with the estimation of major depressive disorder being 17% and persistent depressive disorder being 3%.  These findings vary depending on the methods of identification used (survey versus validated scales) and the population studied.  In general, the prevalence of major depressive disorder is higher than that of persistent depressive disorder, suggesting that the disease course of depression naturally is more often to relapse and remit rather than remain present chronically over an extended time. A study of an urban population of 3720 patients suggests that the prevalence was 15.2% for persistent depressive disorder with persistent major depressive episode (MDE), 3.3% for persistent depressive disorder with pure dysthymia, and 28.2% for major depressive disorder.  In general, when it comes to gender, the prevalence of persistent depressive disorder is two times higher in females than in males, and this is fairly consistent both worldwide and in the US.  While frequency in age groups for persistent depressive disorder is less clear given the recent changes to the condition, in general, depression rates tend to decrease with increasing age, especially age greater than 65. Admittedly, estimates of depression may be low in the elderly due to increasing confounding physical disorders with age.

A careful history is crucial to any psychiatric interview, especially one for diagnostic purposes.  Eliciting symptomatology, severity, and the temporal course helps determine the appropriate DSM diagnosis.  Persistent depressive disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), American Psychiatric Association, Arlington 2013.) is as follows:

The patient must have a depressed mood for at least 2 years.  For children or adolescents, the mood can be irritable instead of depressed, and the time requirement is 1 year.  For both groups, symptoms cannot be absent for greater than 2 months. In addition to depressed/irritable mood, at least 2 of the following symptoms have to be present.  

1. Poor appetite or overeating

2. Insomnia or hypersomnia

3. Low energy/fatigue

4. Low self-esteem

5. Poor concentration/decision making

6. Hopelessness

Note, the DSM-5 has consolidated chronic major depression and dysthymia from DSM-IV into persistent depressive disorder; this means that a patient may meet the criteria for persistent depressive disorder and major depressive disorder at the same time. The DSM-5 has identified specifiers to determine if the persistent depressive disorder is with a pure dysthymic syndrome or with a persistent major depressive episode and whether an episode is current or not.  As always, the above symptoms must cause significant distress and impairment in critical areas of functioning to meet the threshold for diagnosis.

A thorough assessment of patients presenting with mental health symptoms involves ruling out medical and biological causes of symptomatology.  Current and past medical history, as well as current medications, should be part of the psychiatric evaluation to provide context to symptoms.  While routine laboratory screening of an otherwise healthy patient with symptoms of depression is of questionable diagnostic value, the following tests are commonly ordered to support medical decision-making: complete blood count, chemistry panels, urine pregnancy, urine toxicology, and TSH.  Symptoms and patient history often guide additional testing. Validated screening tools for depression, such as the patient health questionnaire, can assist with screening and identification of depressed patients.

In general, the treatment and management of persistent depressive disorder do not vary significantly from the treatment and management of a major depressive disorder.  While there may be differences in the individualization of treatment plans based on symptom number, severity, and chronicity, the general principles of pharmacotherapy and psychotherapy remain the same.  It is also commonly accepted and well-validated that a combination of pharmacotherapy and psychotherapy is more effective than either treatment independently. If antidepressant therapy is indicated, an SSRI (selective serotonin reuptake inhibitor) is the first line typically given the overall efficacy and tolerability of the class.  While other classes such as SNRIs (serotonin-norepinephrine reuptake inhibitor) and atypical antidepressants have also shown efficacy, specific antidepressant selection and management of treatment-resistant depression is beyond the scope of this article.  Psychotherapy selection and type offered is less important (due to similar efficacies) than universal principles such as strong therapeutic rapport, but CBT (cognitive behavioral therapy) and interpersonal therapy appear to be the most commonly studied for the treatment of depression. The cognitive-behavioral analysis system of psychotherapy (CBASP) is a newer modality and the only psychotherapy specifically developed for the management of chronic depression, but it has yet to become standard of care.

Warnings

• Do not take with these medicines: Monoamine Oxidase Inhibitors (MAOIs), and in some cases thioridazine or Orap (pimozide).
• Women should talk to their healthcare providers about the risks of taking these medicines during pregnancy.
• Use with caution if you have narrow-angle glaucoma.

Common Side Effects

• Nausea
• Tremor (shaking)
• Nervousness
• Problems sleeping
• Sexual problems
• Sweating
• Agitation
• Feeling tired

Less Common, but Serious, Side Effects

• Seizures
• Abnormal bleeding or bruising
• Withdrawal symptoms

Ask your healthcare provider about serotonin syndrome.

Getting treatment earlier rather than later can relieve symptoms quicker and reduce the length of time treatment is needed.

Other things that may help include:

• Spending time with other people and talking with a friend or relative about your feelings
• Increasing your level of physical activity. Regular exercise can help people with mild to moderate depression and may be one part of a treatment plan for those with severe depression. Talk with your health care professional about what kind of exercise is right for you.
• Breaking up large tasks into small ones, and tackling what you can as you can. Don't try to do too many things at once
• Delaying important decisions until you feel better. Discuss decisions with others who know you well.
• Keeping stable daily routines. For example, eating and going to bed at the same time every day.
• Avoiding alcohol

As you continue treatment, gradually you will start to feel better. Remember that if you are taking an antidepressant, it may take several weeks for it to start working. Try to do things that you used to enjoy before you had depression. Go easy on yourself.

Antidepressants are medications commonly used to treat depression. They take time to work—usually 4 to 8 weeks—and symptoms such as problems with sleep, appetite, or concentration often improve before mood lifts. It is important to give medication a chance before deciding whether or not it works.

Please Note: Some individuals—especially children, teenagers, and young adults—may experience an increase in suicidal thoughts or behavior when taking antidepressants, particularly in the first few weeks after starting or when the dose is changed. All patients taking antidepressants should be watched closely, especially during the first few weeks of treatment.

Treatment-resistant depression occurs when a person doesn’t get better after trying at least two antidepressants. Esketamine is a newer FDA-approved medication for treatment-resistant depression delivered as a nasal spray in a doctor’s office, clinic, or hospital. It often acts rapidly—typically within a couple of hours—to relieve depression symptoms. Individuals usually continue to take an oral antidepressant to maintain the improvement in depression.

Another option for treatment-resistant depression is to add a different type of medication that may make an antidepressant more effective, such as an antipsychotic or anticonvulsant medication or bupropion, an antidepressant that works differently from most.

Medications prescribed by your health care provider for depression can have side effects, but these may lessen over time. Talk to your provider about any side effects that you have. Do not stop taking medications without the help of a health care provider. If you abruptly stop taking your medicine, you may experience severe withdrawal symptoms.

FDA has not approved any natural products for depression. While research is ongoing, some people find natural products, including vitamin D and the herbal dietary supplement St. John’s wort, to help depression. Do not use St. John’s wort or other dietary supplements for depression before talking to your provider.

Medications called antidepressants can work well to treat depression. They can take 2 to 4 weeks to work. Antidepressants can have side effects, but many side effects may lessen over time. Talk to your health care provider about any side effects that you have. Do not stop taking your antidepressant without first talking to your health care provider.

Please Note: Although antidepressants can be effective for many people, they may present serious risks to some, especially children, teens, and young adults. Antidepressants may cause some people, especially those who become agitated when they first start taking the medication and before it begins to work, to have suicidal thoughts or make suicide attempts. Anyone taking antidepressants should be monitored closely, especially when they first start taking them. For most people, though, the risks of untreated depression far outweigh those of antidepressant medications when they are used under a doctor’s careful supervision.

Psychotherapy (also called “talk therapy” or “counseling”) teaches individuals with depression new ways of thinking and behaving and helps with changing habits that contribute to depression. Most psychotherapy occurs with a licensed, trained mental health professional in one-on-one sessions or with other individuals in a group setting. Two effective psychotherapies to treat depression include cognitive behavioral therapy (CBT) and interpersonal therapy (IPT). The use of older forms of psychotherapy, such as dynamic therapy, for a limited time also may help some people with depression.

With CBT, people learn to challenge and change unhelpful thinking patterns and behavior to improve their depressive and anxious feelings. Recent advances in CBT include introducing mindfulness principles and the development of specialized forms of therapy targeting particular symptoms, such as insomnia.

IPT focuses on interpersonal and life events that impact mood and vice versa. The goal of IPT is to help people improve their communication skills within relationships, establish social support networks, and develop realistic expectations to help them deal with crises or other issues that may be contributing to or worsening their depression.

Brain stimulation therapy, which involves activating or inhibiting the brain directly with electricity or magnetic waves, is another option for some people when other depression treatments have not been effective.

The most common forms of brain stimulation therapy include electroconvulsive therapy and repetitive transcranial magnetic stimulation. Other brain stimulation therapies are newer and, in some cases, still experimental.

Many people with depression turn to complementary health approaches in addition to or in place of conventional treatment. Research suggests that some approaches may be modestly helpful in reducing depression symptoms. For other approaches, benefits are uncertain or there are safety concerns.

Here are 8 things you should know about complementary health approaches for depression:

1. Depression can be a serious illness. Don’t use a complementary health approach to replace conventional care or to postpone seeing a health care provider about symptoms of depression.

2. Some evidence suggests acupuncture may modestly reduce depression symptoms.

3. Music therapy may provide short-term benefits for people with depression.

4. Studies in adults, adolescents, and children have suggested that yoga may be helpful in reducing depressive symptoms.

5. It’s uncertain whether omega-3 fatty acid supplements are helpful for symptoms of depression.

6. Some research on the herb St. John’s wort (Hypericum perforatum) has suggested that it may be helpful for depression symptoms, but not all studies agree. There’s an important concern about the safety of St. John’s wort: it can interact in dangerous, sometimes life-threatening ways with a variety of medicines.

7. Current scientific evidence does not support the use of other dietary supplements, including S-adenosyl-L-methionine (SAMe) or inositol, for depression.

8. Take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions.

Cognitive therapy is a form of psychotherapy that focuses on how a person’s thoughts lead to feelings of distress. The idea behind cognitive therapy is that how you think determines how you feel and act. Cognitive therapists help their clients change dysfunctional thoughts in order to relieve distress. They help a client see how they misinterpret a situation (cognitive distortion). For example, a client may overgeneralize. Because Ray failed one test in his Psychology 101 course, he feels he is stupid and worthless. These thoughts then cause his mood to worsen. Therapists also help clients recognize when they blow things out of proportion. Because Ray failed his Psychology 101 test, he has concluded that he’s going to fail the entire course and probably flunk out of college altogether. These errors in thinking have contributed to Ray’s feelings of distress. His therapist will help him challenge these irrational beliefs, focus on their illogical basis, and correct them with more logical and rational thoughts and beliefs.

Cognitive therapy was developed by psychiatrist Aaron Beck in the 1960s. His initial focus was on depression and how a client’s self-defeating attitude served to maintain a depression despite positive factors in her life (Beck, Rush, Shaw, & Emery, 1979). Through questioning, a cognitive therapist can help a client recognize dysfunctional ideas, challenge catastrophizing thoughts about themselves and their situations, and find a more positive way to view things (Beck, 2011).

Depression, in general, has a substantial impact on both morbidity and mortality and a common cause of global disease burden and disability worldwide. Persistent depressive disorder represents a disorder of chronic depression, and outcomes and prognosis are similar if not worse than those of major depressive disorder depending on whether or not the disorder represents dysthymia or chronic major depression. Outcomes of a 10-year study suggest that persistent depressive disorder is independently associated with greater severity of depression, anxiety, and somatic symptoms in comparison to major depressive disorder.

Complications of untreated depression are similar to those complications of other untreated mental illnesses. It is commonly accepted that untreated depression broadly impacts healthcare resulting in increased healthcare costs as well as decreased medication adherence and treatment compliance in those with medical problems. In multiple studies, depression has been shown to lead to additive functional impairment and increase symptom burden in those with chronic medical illnesses. Additionally, there is evidence suggesting that depression increases mortality.