By Dr. David Woo - August 15, 2022

Persistent depression (persistent depressive disorder), formerly known as dysthymia, is a chronic type of depression characterized by prolonged bouts of depression symptoms that last a minimum of two years, with no more than a two-month gap between symptoms.(1,2,3,4) 

Symptoms of Persistent Depression

Persistent depression shares the same symptoms as major depressive disorder (MDD), but symptoms are typically milder for people with persistent depression than for major depression. While persistent depression symptoms are less severe than major depression symptoms, persistent depression symptoms can certainly be severe from time to time.(1,2,3,4)

Symptoms of persistent depression may include:(1)

• Less interest in regular activities
• Feelings of sadness, emptiness, and worthlessness
• Feelings of hopelessness and guilt
• Feeling more tired or lethargic than usual
• Difficulty focusing and making decisions
• Anger and irritability
• Self-isolation
• Changes in appetite and eating habits
• Changes in sleep patterns

Possible Causes of Persistent Depression

As with major depression, the causes of persistent depression are unknown. However, researchers believe that the condition may stem from multiple factors:(1,5,6,7)

• Depressive symptoms have been correlated with hyperactivity (overactivity) and hypoactivity (underactivity) in certain brain networks that moderate the response to emotional stimuli. These irregular activity levels lead to dysfunction in mood and stress regulation and can lead to depressive symptoms.
• Persistent depression may be influenced by genetics, as having persistent depression is correlated with having blood relatives (i.e. parent, sibling, cousin, etc.) who also have persistent depression. However, studies have not yet identified any genes that appear to be responsible for persistent depression.
• Similarly to major depression, persistent depression may be precipitated by a significant traumatic life event, such as chronic stress, injury, or loss of a loved one.
• Current scientific research is identifying other risk factors that involve chemical and/or anatomical changes in the brain that seem to be correlated with depression. It is not clearly understood if these characteristics are the causes or results of depression or both.

Treatment for Persistent Depression

A combined treatment of talk therapy and medication is the most effective treatment for relieving symptoms of persistent depression. People with persistent depression may be prescribed antidepressants, a type of medication designed to correct chemical imbalances in the brain thought to cause some cases of depression.(1,8,9) 

Finding the right medication can take time, and some patients may need to try more than one antidepressant before finding the right one for them. Antidepressants typically can start working within a few weeks, although some people will need to take them for longer before they see a difference in their symptoms.(1,8,9)

While antidepressants are effective in treating depression symptoms for many patients, especially those with moderate to severe depression, approximately 30% of people who take antidepressants won’t see an improvement in their symptoms. When this occurs, it’s referred to as treatment-resistant depression.(8,10) 

Just because someone doesn’t find relief from depression symptoms with antidepressants doesn’t mean that there isn’t hope for them. An FDA-approved therapy for treatment-resistant depression, called transcranial magnetic stimulation or TMS, could help. 

Transcranial Magnetic Stimulation (TMS) Treatment for Persistent Depression

Transcranial magnetic stimulation (TMS) is a medication-free treatment that uses magnetic pulses to regulate activity in regions of the brain associated with mood. TMS is proven to be safe and effective at treating symptoms of depression, even for patients who are considered treatment-resistant or medication-resistant.(11,12) 

While antidepressants may not work for everyone, some people might feel nervous to stop taking their antidepressant during TMS treatment. The good news is that TMS can be used to augment or increase the positive effects of antidepressants, and therefore can be performed while someone continues taking their antidepressant.(11,12,13)

Learn More About Treatment for Persistent Depression

If you or a loved one are experiencing symptoms of persistent depression, seek help from a mental health professional. Only a licensed physician can properly diagnose symptoms of depression and help you get the care you need. To learn more about treatment for persistent depression at Madison Ave TMS & Psychiatry, contact us online or call (212) 731-2033.

Resources:

1. Persistent depressive disorder (dysthymia). MayoClinic. Published December 8, 2018. Link. Accessed July 16, 2022.

2. Persistent Depressive Disorder (Dysthymic Disorder). National Institute of Mental Health. Date of publication unavailable. Link. Accessed July 16, 2022.

3. Persistent depressive disorder. National Library of Medicine. Updated July 1, 2021. Link. Accessed July 16, 2022.

4. Persistent Depressive Disorder (PDD). Cleveland Clinic. Updated March 8, 2021. Link. Accessed July 16, 2022.

5. Causes of Depression. WebMD. Reviewed March 8, 2021. Link. Accessed July 16, 2022.

6. Physical Effects of Depression on the Brain. WebMD. Reviewed July 28, 2020. Link. Accessed July 16, 2022.

7. Neuroscience of depression and treatment. New Frontiers Psychiatry & TMS. Published November 8, 2021. Link. Accessed July 16, 2022.

8. Depression: How Effective Are Antidepressants? National Library of Medicine. Updated June 18, 2020. Link. Accessed July 16, 2022.

9. Antidepressants: Selecting one that’s right for you. MayoClinic. Published December 31, 2021. Link. Accessed July 16, 2022.

10. Ionescu DF, Rosenbaum JF, Alpert JE. Pharmacological approaches to the challenge of treatment-resistant depression. Dialogues Clin Neurosci. 2015;17(2):111-126. Link. Accessed July 16, 2022.

11. Somani A, Kar SK. Efficacy of repetitive transcranial magnetic stimulation in treatment-resistant depression: the evidence thus far. Gen Psychiatr. 2019;32(4):e100074. Published 2019 Aug 12. Link. Accessed July 16, 2022.

12. What is TMS – Transcranial Magnetic Stimulation? Madison Ave TMS & Psychiatry. Updated September 21, 2022. Link. Accessed July 16, 2022.

13. De Risio L, Borgi M, Pettorruso M, et al. Recovering from depression with repetitive transcranial magnetic stimulation (rTMS): a systematic review and meta-analysis of preclinical studies. Transl Psychiatry. 2020;10(1):393. Published 2020 Nov 10. Link. Accessed July 16, 2022.

Dr. David Woo

Dr. Woo has been seeing patients in private practice since 2002, always with the goals of combining evidence-based medicine with psychodynamic psychotherapy and collaborating with other mental health professionals to ensure the best possible outcomes for his patients. He has been certified to administer TMS at his practice since 2017. His greatest clinical interests include helping patients suffering from depression, anxiety, and obsessive compulsive disorder.