PITTSBURGH, Aug. 12 (UPI) -- For some depression patients, antidepressant medications and therapy may not work because of metabolic abnormalities interfering with brain function, according to a recent study.
Researchers in Pittsburgh found nearly two-thirds of patients with treatment-resistant depression also had a deficiency in neurotransmitter metabolism, suggesting a different target for treatment.
The researchers report the recent study was inspired by a young depression patient who had seen no relief from any of the standard treatments for depression. A series of biochemical tests revealed the patient was deficient in the cerebrospinal fluid biopterin, which is involved in the synthesis of several neurotransmitters.
Once the deficiency was corrected, the patient's depression symptoms mostly disappeared, leading to researchers looking for similar conditions in other difficult-to-treat depression cases.
"This is a potentially transformative finding for certain groups of people with depression," Dr. Lisa Pan, a professor psychiatry and clinical and translational science at the University of Pittsburgh School of Medicine, said in a press release.
For the study, published in the American Journal of Psychiatry, researchers tested 33 adolescent and young adults with treatment-resistant depression for metabolic abnormalities, recruiting an additional 16 teens as a control group.
Compared to controls, 64 percent of depression patients had some type of deficiency in neurotransmitter metabolism, though specific metabolite deficiencies varied among patients. None of the controls had similar deficiencies.
The researchers treated patients with deficiencies, finding their depression symptoms improved or were fully alleviated, suggesting a method for helping patients with difficult to treat depression.
"It's really exciting that we now have another avenue to pursue for patients for whom our currently available treatments have failed," Pan said.