More than 90% of COVID-19 patients respond significantly more than would be expected to common depression medications, the results of a new pilot study suggest.

In fact, these patients responded better to selective serotonin reuptake inhibitors (SSRIs)— a widely-used class of antidepressants — than is typical for patients who have not had COVID-19, investigator Mario Mazza, M.D., San Raffaele University in Italy, said.

Mazza and team treated 58 patients with SSRIs such as sertraline, paroxetine, fluvoxamine and citalopram. Normally, about one third of patients with depression will not respond to these drugs. But among study participants with post-COVID depression, 91% did respond favorably to the drugs within four weeks.

This may suggest a path to relief for people grappling with long-lasting effects of COVID-19, Mazza and colleagues said. Depression and COVID-19 appear to be linked, with about 40% of patients developing the mental health condition within six months of infection, they reported.

The results indicate that post-COVID depression is treatable, Mazza said. He and his colleagues are planning a larger-scale trial, and will investigate whether SSRIs also can be beneficial to patients with other post-COVID symptoms, such as cognitive impairment and fatigue. They will also examine the role inflammation plays in post-COVID symptoms.

Some patients experience persistent physical, psychological and neurocognitive symptoms after a COVID-19 infection, explained one expert who reviewed the results.

“Even if we still do not understand all the causes of long COVID, this study indicates post-COVID depressive symptoms respond very well to serotonergic antidepressants,” said Livia De Picker M.D., Ph.D., of the University of Antwerp, Belgium, who was not involved in the investigation.

“[R]ecent studies have pointed out such compounds may also protect patients against severe COVID-19 illness and several antidepressants are currently under study as COVID-19 treatment options,” she said. 

The study was presented at the ECNP Conference in Lisbon, and has been accepted for publication by the journal European Neuropsychopharmacology.