What is Persistent Depressive Disorder?

While not as serious or disabling as other forms of clinical depression, persistent depressive disorder (PDD) is a more chronic form of persistent depression. It is characterized by a depressed mood or loss of interest or pleasure in almost all activities most of the time for at least two years. PDD, also known as dysthymia, can occur alone or in conjunction with other mood or psychiatric disorders. People with PDD are at higher risk for anxiety and substance use disorders.

Signs and Symptoms

For a diagnosis of persistent depressive disorder, two or more of the following symptoms must be present for most of the day, for more days than not, during a two-year period:

• Poor appetite or overeating.
• Insomnia (inability to sleep) or hypersomnia (excessive sleepiness)
• Fatigue or loss of energy
• Low self esteem
• Feelings of hopelessness
• Diminished ability to think, concentrate or make decisions

The symptoms mentioned above must:

• Cause significant distress/impairment in social, occupational or other functional areas
• Not be attributable to physiological effects of a substance or other medical condition
• Not be better explained by schizoaffective disorder, schizophrenia, schizophreniform disorder, delusional disorder, or other specified and unspecified schizophrenia spectrum and other psychotic disorders
• Not occur in addition to a manic episode (a mood state characterized by period of at least one week where an elevated, expansive, or unusually irritable mood exists) or hypomanic episode (a distinct period of abnormally and persistently elevated, expansive or irritable mood and abnormally and persistently increased activity or energy, lasting at least four consecutive days and present most of the day, nearly every day) 

Diagnosis

Diagnosing persistent depressive disorder requires thorough physical and psychological evaluation. Your behavioral health physician will use the criteria for depression listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published by the American Psychiatric Association, to determine if your symptoms indicate persistent depressive disorder.

Diagnostic tests include:

Blood tests: Your physician may order a complete blood count or test your thyroid hormone levels to be sure the thyroid is functioning properly.

Physical examination: Your physician will perform a physical exam and ask questions about your health to determine if your symptoms could be linked to an underlying physical health problem.

Psychiatric evaluation: Your behavioral health physician will ask about your symptoms, thoughts, feelings and behavior patterns. You may be asked to fill out a questionnaire to help answer these questions.

Causes

The cause of persistent depressive disorder is unknown, but symptoms can stem from a variety of factors, including chronic stress and trauma at an early age.

Risk Factors

Risk factors that could contribute to persistent depressive disorder include:

Traumatic or highly stressful events: Loss or separation from parents in early childhood increases the risk for PDD.

Family history: Persistent depressive disorder is more common in people whose blood relatives also have the condition. Research into genetic causes of depression is ongoing. 

Brain chemistry: Neurotransmitters, naturally occurring brain chemicals, likely play a role in depression. Recent research indicates that changes in the function and effects of these neurotransmitters and how they interact with neurocircuits involved in maintaining mood stability may play a significant role in depression and its treatment.

Prevention

While most risk factors for persistent depressive disorder are unknown, or can’t be controlled, there are ways you can help improve your mental health:

Don’t abuse alcohol or recreational drugs: These substances have a mood-altering effect that could trigger depressive symptoms.

Seek help for known behavioral issues: If you recognize – or have been told by others – that you have low self-esteem, dependent tendencies, or self-critical or pessimistic tendencies, behavioral health counseling or therapy may help.

Seek support for stress: Lean on family and friends, if possible, during stressful situations. Talking to a behavioral health professional can also help you develop effective coping strategies.

Prognosis

Most cases of persistent depressive disorder can be treated – and the earlier treatment begins, the more effective it tends to be.

Treatment

Most people with persistent depressive disorder benefit most from a combination of medication and psychotherapy delivered by a psychiatrist, psychologist or other behavioral health professional.

Medication

You may need to try a few different antidepressant medications, or medication combinations, before you find the one that’s right for you. Some medications take a few weeks before their full effect is obvious. Some cause side effects for certain patients. If you experience any side effects, it’s important to talk to your physician immediately but not to abruptly stop taking the medication, which could cause a worsening of symptoms.

Discuss all potential risks of your prescribed medication. Many antidepressants shouldn’t be taken by pregnant or nursing mothers, as they could harm the baby. Others shouldn’t be taken by children, teens or younger adults because they can increase suicidal thoughts.

Most antidepressants are generally safe, but their prescription and use should always be under the guidance of a medical professional.

Common antidepressants include:

Selective serotonin reuptake inhibitors (SSRIs): These first-line antidepressants are considered safer than other types and tend to cause fewer disruptive side effects. They increase levels of serotonin in the brain.

Serotonin-norepinephrine reuptake inhibitors (SNRIs): These block the reabsorption of the neurotransmitters serotonin and norepinephrine in the brain. 

Tricyclic antidepressants: These older drugs can be very effective but tend to cause more severe side effects than newer antidepressants, like SSRIs. They increase levels of norepinephrine and serotonin and block the action of acetylcholine, another neurotransmitter.

Monoamine oxidase inhibitors (MAOIs): These drugs may be prescribed when others haven’t worked. They’re rarely first-line treatments because they can have serious side effects and require avoidance of certain foods and other drugs, which can cause dangerous or even deadly interactions. An enzyme called monoamine oxidase helps remove neurotransmitters norepinephrine, serotonin and dopamine from the brain. MAOIs prevent this from happening, making more of these brain chemicals available to effect changes in brain cells and circuits.

Atypical antidepressants: These don’t fit into other classes of antidepressants, but each still works in its own way to affect neurotransmitters used to communicate between brain cells. 

Other medications: Your physician may recommend adding mood stabilizers, anti-anxiety or anti-psychotic drugs to enhance the effects of your antidepressant. 

Psychotherapy

Also known as talk therapy or psychological therapy, this involves talking about your condition, symptoms, mental health history and life with a mental or behavioral health professional. This type of therapy can help you find effective coping mechanisms, replace negative beliefs and behaviors with positive ones, set realistic goals, develop health problem-solving strategies, identify triggering issues in your lifestyle or relationships, and regain a sense of control or satisfaction in your life. 

Other Treatment Options

Lifestyle changes: Certain healthy habits can help support the treatment plan for PDD, including regular sleep patterns, daily exercise and healthy eating.

Complications

Persistent depressive disorder can get worse if it’s not treated, leading to problems that can affect a person’s emotions, physical health, social life, occupation and daily functioning. Examples of these complications include:

Alcohol or drug abuse: These can have negative effects on physical health, safety and relationships.

Excess weight gain or malnutrition: Overeating or undereating puts a person at risk for a variety of health conditions. 

Other psychological issues: These may include anxiety, panic disorders or social phobias.

Self-mutilation: Some people with persistent depressive disorder turn to self-harm, like cutting, as a very dangerous and destructive coping mechanism.

Social distress or isolation: This may lead to conflicts with family and friends, problems at work or school, and deeper depression. 

Suicidal feelings: These can lead to suicide attempts or actual suicide.