A new peer-reviewed study published in Brain Medicine suggests that treating autonomic dysfunction can relieve symptoms for people diagnosed with treatment-resistant depression, according to a Mar. 31 release. The research followed more than 8,000 patients over six years at clinical practices in Philadelphia, Memphis, and New York City.
The findings are significant because many individuals labeled as having treatment-resistant depression have not responded to multiple psychiatric medications. The study proposes that undetected issues with the autonomic nervous system may underlie their persistent symptoms.
Researchers tracked 2,197 patients with both documented autonomic dysfunction and prior diagnoses of depression or similar symptoms. Most arrived with an average of more than twenty different autonomic complaints such as fatigue, brain fog, sleep disturbances, memory lapses, gastrointestinal problems, hormone imbalances—especially among women—and chronic pain. Each patient showed measurable problems in the parasympathetic and sympathetic branches of their nervous systems.
Two main types of dysfunction were found: alpha-sympathetic withdrawal—which causes blood pooling in the legs and reduced flow to the brain—and parasympathetic excess—which results in inappropriate vessel relaxation and forces the heart to work harder. A third type, beta-sympathetic excess, was seen as a compensatory mechanism by the body. Standard testing often misses these distinctions; however, this study used P&S Monitoring technology to separate out each branch’s activity more precisely.
Treatment focused on low doses of medication or non-pharmaceutical interventions like R-alpha-lipoic acid and structured walking programs originally designed for astronauts recovering from zero gravity effects. Within three months most patients reported better sleep; after nine months their average number of symptoms dropped sharply from over twenty-three to just above five. "What we found...was that these patients were not treatment resistant in any meaningful psychiatric sense," said Dr. Joe Colombo from Franklin Cardiovascular Autonomic Dysfunction and POTS Center in Sicklerville, New Jersey.
Nearly half had also been diagnosed with long- or post-COVID syndrome—a group now known for high rates of autonomic issues—while others had hypertension or diabetes that appeared linked to underlying nervous system imbalance rather than primary cardiac causes alone.
The authors acknowledge limitations: there was no control group; depressive symptoms were measured through an overlapping but non-standard questionnaire; all participants came from specialized clinics; and intensive clinician contact could have affected outcomes through expectation or placebo effects. They recommend future randomized controlled studies using standard psychiatric rating scales alongside objective measures of nervous system function.
"For too long psychiatry has accepted the label of treatment-resistant depression as a verdict rather than a question... If a significant proportion...have measurable autonomic dysfunction fueling their symptoms then we have a responsibility to screen for it," said Dr. Michele T. Pato from Rutgers University’s Department of Psychiatry.
The researchers stress this approach is not meant as a replacement for psychiatric care but rather provides an important physiological foundation before traditional treatments are considered fully effective.
