There’s good news today for parents who’ve been extremely frustrated by the inability of experts to agree on what causes acute-onset OCD—first called PANDAS, and now PANS—and even whether it exists or not.

This is an often very serious syndrome that includes severe OCD along with a host of other disturbing symptoms and behaviors: tics, emotional instability, irritability, aggression, developmental regression, motor abnormalities, incontinence, and eating problems. Parents say it comes on virtually overnight, and it does not respond predictably to standard OCD treatments.

PANS (pediatric acute neuropsychiatric syndrome) is thought by many to be an autoimmune response to an infection—often, but not always, strep—that can be treated with some success with antibiotics and IVIG, a treatment used for autoimmune illnesses. But for decades, others have questioned whether the condition is real, is really linked to infection, or whether treatment with antibiotics has been proven effective.

Now an interdisciplinary group of PANDAS and PANS clinicians and researchers have developed a consensus report, published in the Journal of Child and Adolescent Psychopharmacology, that spells out what is known about the condition and how it should be diagnosed. The group met in May of 2013 for what they called the First PANS Consensus Conference to try to hammer out diagnostic boundaries and specific criteria for PANS, as well as a very detailed evaluation process, including medical testing. While it’s aimed at clinicians and researchers, this could also be helpful for parents who still have a hard time persuading doctors to do the tests that are needed to rule out alternatives and confirm a diagnosis of PANS.

“Many children with PANS are extremely ill, with extreme compulsions (licking shoes, barking), motor and phonic tics (whooping, wringing hands), behavioral regression, and terrifying episodes of extreme anxiety or aggression,” writes Dr. Kiki Chang, a professor of psychiatry at the Stanford University School of Medicine, and one of the coauthors of the report. “The behavioral manifestations often prompt rapid referral to psychological or psychiatric services, but all patients should receive a full medical evaluation.”

The consensus report is part of a special issue of the journal devoted to PANDAS and PANS that will be published in January. You can download the report here.