Dogs (Doberman
pinschers) and humans affected by OCD
have similar brain abnormalities – namely: “MRI brain images of eight
Dobermans with CCD to the control group, Ogata found that the CCD group had
higher total brain and gray matter volumes, lower gray matter densities in the
dorsal anterior cingulate cortex and right anterior insula, and higher
fractional anisotropy in the splenium of the corpus callosum (the degree of
which correlated with the severity of the behavioral traits). These findings
are consistent with those reported in humans with OCD.”
“The causes of OCD, which affects about 2 percent of the population, are not well understood and the disorder often goes untreated or undiagnosed for decades. People with OCD often exhibit repetitive behaviors or persistent thoughts that are time consuming and interfere with daily routines. Dogs with CCD engage in repetitious and destructive behaviors such as flank- and blanket-sucking, tail chasing, and chewing. However, both OCD and CCD often respond to similar treatments.”
“The causes of OCD, which affects about 2 percent of the population, are not well understood and the disorder often goes untreated or undiagnosed for decades. People with OCD often exhibit repetitive behaviors or persistent thoughts that are time consuming and interfere with daily routines. Dogs with CCD engage in repetitious and destructive behaviors such as flank- and blanket-sucking, tail chasing, and chewing. However, both OCD and CCD often respond to similar treatments.”
Surgery effective for nearly 50% of treatment resistant OCD:
Standard treatments for the disorder are antidepressant
medication and/or psychotherapeutic help such as cognitive behavioural therapy,
but other studies have shown that such treatment does not help relieve symptoms
for between 20-30% of patients…Nineteen patients were studied who had a severe
form of OCD that had not responded to drugs or psychotherapeutic treatment. All
of these patients underwent psychosurgery in the form of bilateral capsulotomy
between 1997 and 2009.
Their results showed that 36.8% of the patients responded
fully to the procedure and 10.5% were considered partial responders, meaning
that almost half of the patients (47.3%) responded to the surgery.
OCD linked to obesity in mice genome:
“His mouse model of compulsivity lacks a brain protein
called SAPAP3. These mice groom themselves excessively to the point of
lesioning their skin, and their compulsive behavior can be effectively treated
by fluoxetine, a drug that is commonly used to treat OCD in people… a mouse
that genetically mimics an inherited form of human obesity. This mouse lacks a
brain protein known a MC4R. Mutations in the MC4R gene are the most common
single-gene cause of morbid obesity and over-eating in people… An old study
hinted that in addition to its role in food intake and obesity, MC4R might also
play a role in compulsive behaviour… we decided to breed the two mice together
to see if it would have an effect on compulsive grooming."
The
experiment proved their original hypothesis -- knocking out the MC4R protein in
the OCD mouse normalized grooming behavior in the animals. In addition,
chemically blocking MC4R in the OCD mice also eliminated compulsive grooming.
The rescued behavior is mirrored by normalization of a particular pattern of
brain cell communication linked to compulsive behavior.
However,
the breeding experiment revealed another totally unexpected result. Loss of the
SAPAP3 protein from the mice that were obese due to lack of MC4R produced mice
of normal weight.
"We
had this other, completely shocking finding -- we completely rescued body
weight and food intake in the double null mouse," Lutter says. "So,
not only were we affecting the brain regions involved in grooming and behavior,
but we also affected the brain regions involved in food intake and body
weight."
"Food safety has been an issue through the entire course of human evolution – refrigeration is a relatively recent invention," he says. "Obsessive behavior, or fear of contamination, may be an evolutionary protection against eating rotten food."
"Food safety has been an issue through the entire course of human evolution – refrigeration is a relatively recent invention," he says. "Obsessive behavior, or fear of contamination, may be an evolutionary protection against eating rotten food."
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