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Childhood disorder prompts study of infection link to mental illness

Cases of children suddenly exhibiting obsessive-compulsive disorder after strep has led to studies that reinforce the belief that some mental illnesses can be triggered by an immune response.

December 05, 2011|By Shari Roan, Los Angeles Times
  • Brody Kennedy, with his mother, Tracy Kennedy and his cat Boogie Su, showed symptoms of obsessive-compulsive disorder after a bout of strep throat. His mother says the cat helped calm him.
Brody Kennedy, with his mother, Tracy Kennedy and his cat Boogie Su, showed… (Kirk McKoy, Los Angeles…)

Brody Kennedy was a typical sixth-grader who loved to hang out with friends in Castaic and play video games. A strep-throat infection in October caused him to miss a couple of days of school, but he was eager to rejoin his classmates, recalls his mother, Tracy.

Then, a week after Brody became ill, he awoke one morning to find his world was no longer safe. Paranoid about germs and obsessed with cleanliness, he refused to touch things and showered several times a day. His fear prevented him from attending school, and he insisted on wearing nothing but a sheet or demanding that his mother microwave his clothes or heat them in the dryer before dressing.

So began a horrific battle with a sudden-onset mental illness that was diagnosed as pediatric autoimmune neuropsychiatric disorder associated with streptococcus, or PANDAS. The puzzling name describes children who have obsessive-compulsive disorder that occurs suddenly — and often dramatically — within days or weeks of a simple infection, such as strep throat.

"He washed his hands over and over and was using hand-sanitizer nonstop," said Tracy Kennedy, who has home-schooled her 11-year-old son since early November. "He had never been like this before. Ever. He just woke up with it."

The bizarre illness, first recognized in the mid-1990s, has been cloaked in controversy. Now, however, studies are reinforcing the belief that some psychiatric illnesses can be triggered by ordinary infections and the body's immune response. While the theory remains unproved, the research raises the possibility that some cases of mental illness might be cured by treating the immune system dysfunction.

"Some people get sick with whatever infection, and they recover and they're fine," says M. Karen Newell Rogers, an immunologist at Texas A&M Health Science Center College of Medicine in Temple, Texas, who studies such illnesses. "Other people get sick and recover, but they are not the same."

PANDAS is thought to be caused by antibodies generated as a result of an infection, usually strep. Normally, an infection causes the body to generate antibodies that fight the infection and promote healing. But in PANDAS, the antibody response is thought to go awry, attacking brain cells and resulting in OCD symptoms.

A greater understanding of the link between strep and OCD has opened the door to the study of other psychiatric or neurological illnesses that may be linked to improper immune response, including cases of autism, schizophrenia and anorexia.

"The whole area of mental illness caused by infections is being looked at more closely because of PANDAS," says Dr. Michael A. Jenike, a professor of psychiatry at Harvard Medical School and chairman of the International OCD Foundation's scientific advisory board. "If you can prevent lifelong suffering by using antibiotics or some acute intervention, that would be huge."

Little understood disorder

PANDAS is generally poorly understood in the medical field, said Dr. Margo Thienemann, a Palo Alto child psychiatrist who has treated several cases. There is no test to help doctors diagnose it, although the National Institute of Mental Health says that PANDAS can be identified after two or three episodes of OCD or tics that occur in conjunction with strep infection — a vague guideline that results in much confusion.

Thienemann says patients tend to fall between the cracks of psychiatry and immunology. But early diagnosis is important.

"In psychiatry, we generally spend our time treating diseases without knowing the reason they happen," she says. "With PANDAS we are able to see the cause of a problem rather than the downstream effects. This is the exciting part."

OCD affects about 1% of people and can feature a fear of contamination by germs or other substances, hoarding, intense anxiety over one's moral behavior, tics, compulsive skin-picking or body dysmorphic disorder (obsession with some perceived bodily imperfection). The disorder tends to run in families and usually appears around the ages of 10 to 12, with a later spike in rates from age 18 to 22.

No one knows what portion of obsessive-compulsive disorder cases may be tied to PANDAS — or even how prevalent the condition may be, Jenike says.

"I used to think it was exceedingly rare," he says. "Now I think it's exceedingly common."

Recent research has strengthened support for PANDAS. For instance, one study demonstrated that in mice prone to autoimmune disorders (in which the immune system attacks healthy cells), exposure to strep led to OCD-like behavior. The study was published in 2009 in the journal Molecular Psychiatry.

A 2010 Yale study found that tic symptoms worsened somewhat in children with OCD following a strep infection. That study, published in Biological Psychiatry, suggests some children are vulnerable to flare-ups of OCD symptoms when stressed by infections.

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