Posts Tagged obsessive-compulsive disorder

[WEB SITE] OCD: Brain mechanism explains symptoms

A large review of existing neuroscientific studies unravels the brain circuits and mechanisms that underpin obsessive-compulsive disorder. The researchers hope that the new findings will make existing therapies more effective, “or guide new treatments.”
doctors looking at brain scans

New research analyzes the brain scans of almost 500 people to unravel the brain mechanisms in OCD.

Obsessive-compulsive disorder (OCD) is a mental health condition that affects more than 2 million adults in the United States.

People with OCD often experience recurring, anxiety-inducing thoughts or urges — known as obsessions — or compulsive behaviors that they cannot control.

Whether it is repeatedly checking if the door is locked or switching lights on and off, OCD symptoms are uncontrollable and can severely interfere with a person’s quality of life.

Treatments for OCD include medication, psychotherapy, and deep brain stimulation. However, not everyone responds to treatment.

In fact, reference studies have found that only 50 percent of people with OCD get better with treatment, and just 10 percent recover fully.

This treatment ineffectiveness is partly down to the fact that medical professionals still do not fully understand the neurological roots of the condition. A new study, however, aims to fill this gap in research.

Scientists led by Luke Norman, Ph.D., a postdoctoral research fellow in the Department of Psychiatry at the University of Michigan (U-M) in Ann Arbor, corroborated and analyzed large amounts of data from existing studies on the neurological underpinnings of OCD.

The scientists published their meta-analysis in the journal Biological Psychiatry.

Studying the brain circuitry in OCD

Norman and colleagues analyzed studies that scanned the brains of hundreds of people with OCD, as well as examining the brain images of people without the condition.

“By combining data from 10 studies, and nearly 500 patients and healthy volunteers, we could see how brain circuits long hypothesized to be crucial to OCD are indeed involved in the disorder,” explains the study’s lead author.

Specifically, the researchers zeroed in on a brain circuit called the “cingulo-opercular network.” This network involves several brain regions that are interconnected by neuronal pathways in the center of the brain.

Studies have previously associated the cingulo-opercular network with “tonic alertness” or “vigilance.” In other words, areas in this brain circuit are “on the lookout” for potential errors and can call off an action to avoid an undesirable outcome.

Most of the functional MRI studies included by Norman and colleagues in their review had volunteers respond to errors while inside the brain scanner.

An analysis of data from the various studies revealed a salient pattern: Compared with people who did not have OCD, those with the condition displayed significantly more activity in brain areas associated with recognizing an error, but less activity in the brain regions that could stop an action.

Study co-author Dr. Kate Fitzgerald of U-M’s Department of Psychiatry explains the findings, saying “We know that [people with OCD] often have insight into their behaviors, and can detect that they’re doing something that doesn’t need to be done.”

She adds, “But these results show that the error signal probably isn’t reaching the brain network that needs to be engaged in order for them to stop doing it.”

The researcher continues using an analogy.

It’s like their foot is on the brake telling them to stop, but the brake isn’t attached to the part of the wheel that can actually stop them.”

Dr. Kate Fitzgerald

“This analysis sets the stage for therapy targets in OCD because it shows that error processing and inhibitory control are both important processes that are altered in people with the condition,” says Fitzgerald.

Findings may boost existing treatments

The researcher also explains how the findings may enhance current treatments for OCD, such as cognitive behavioral therapy (CBT).

“In [CBT] sessions for OCD, we work to help patients identify, confront, and resist their compulsions, to increase communication between the ‘brake’ and the wheels, until the wheels actually stop. But it only works in about half of patients.”

“Through findings like these, we hope we can make CBT more effective, or guide new treatments,” Dr. Fitzgerald adds. The team is currently recruiting participants for a clinical trial of CBT for OCD.

In addition to CBT, Dr. Fitzgerald also hopes that the results will enhance a therapy known as “repetitive transcranial magnetic stimulation” (rTMS).

“If we know how brain regions interact together to start and stop OCD symptoms, then we know where to target rTMS,” she says. “This is not some deep dark problem of behavior,” Dr. Fitzgerald continues.

OCD is a medical problem, and not anyone’s fault. With brain imaging, we can study it just like heart specialists study EKGs of their patients — and we can use that information to improve care and the lives of people with OCD.”

Dr. Kate Fitzgerald

via OCD: Brain mechanism explains symptoms

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[WEB SITE] OCD: Cognitive behavioral therapy improves brain connectivity

MRI scans show that people diagnosed with OCD who have undergone CBT have intensified connectivity between key brain networks.

Researchers have used brain scans to measure changes in the cerebral activity of people with obsessive-compulsive disorder after undergoing a type of cognitive behavioral therapy. They found that the connectivity of key brain networks is improved, suggesting new targets for therapy.

Obsessive-compulsive disorder (OCD) is a condition marked by inescapable, intrusive thoughts that cause anxiety (hence “obsessive”), and repetitive, ritualistic behaviors aimed at reducing that feeling (hence “compulsive”).

OCD can be a debilitating condition and can severely impair daily functioning. The National Institutes of Mental Health estimate that, in the United States, the yearly prevalence of OCD amounts to 1 percent of the total adult population. Around half of these cases are deemed “severe.”

Treatments for OCD include the administration of selective serotonin reuptake inhibitors and cognitive behavioral therapy (CBT), a type of therapy that aims to improve damaging mind associations.

Researchers from the University of California, Los Angeles – who were led by Dr. Jamie Feusner – have conducted a study aiming to find out whether and how CBT might change levels of activity and network connectivity in the brains of people diagnosed with OCD.

They explain that although the efficacy of CBT in treating OCD has been previously explored, this is likely the first study to use functional MRI (fMRI) to monitor what actually happens in the brains of people with OCD after exposure to this kind of therapy.

The researchers’ findings were recently published in the journal Translational Psychiatry.

Changes in key brain regions following CBT

The team specifically targeted the effects of exposure and response prevention (ERP)-based CBT, which entails exposure to triggering stimuli and encouraging the individual to wilfully resist responding to those stimuli in the way that they normally would.

For the study, 43 people with OCD and 24 people without it were recruited. The results for the two groups were later compared, at which point the 24 individuals without OCD were taken as the control group.

All the participants diagnosed with OCD received intensive ERP-based CBT on an individual basis in 90-minute sessions on 5 days per week, for a total of 4 weeks.

Participants from both groups underwent fMRI. Those diagnosed with OCD, who had received CBT, were scanned both before the treatment period and after the 4 weeks of treatment. Participants from the control group, who did not undergo CBT, also had fMRI scans after 4 weeks.

When the scans of participants with OCD were compared, the results from before exposure to CBT and after it were found to be largely contrasting.

The researchers noticed that the brains of people with OCD exhibited a significant increase in connectivity between eight different brain networks, including the cerebellum, the caudate nucleus and putamen, and the dorsolateral and ventrolateral prefrontal cortices.

 The cerebellum is involved with processing information and determining voluntary movements, while the caudate nucleus and putamen are key in learning processes and controlling involuntary impulses.

The dorsolateral and ventrolateral prefrontal cortices are involved with planning action and movement, as well as regulating certain cognitive processes.

Dr. Feusner and team point out that an increased level of connectivity between these cerebral regions suggests that the brains of the people who underwent CBT were “learning” new non-compulsive behaviors and activating different thought patterns.

He suggests that these changes may be novel ways of coping with the cognitive and behavioral idiosyncrasies of OCD.

The changes appeared to compensate for, rather than correct, underlying brain dysfunction. The findings open the door for future research, new treatment targets, and new approaches.”

Dr. Jamie Feusner

First study author Dr. Teena Moody adds that being able to show that there are quantifiable positive changes in the brain following CBT may give people diagnosed with OCD more confidence in following suitable treatments.

“The results could give hope and encouragement to OCD patients,” says Dr. Moody, “showing them that CBT results in measurable changes in the brain that correlate with reduced symptoms.”

Source: OCD: Cognitive behavioral therapy improves brain connectivity

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[WEB SITE] How OCD and Traumatic Brain Injury Are Linked

Traumatic brain injuries can cause symptoms of obsessive compulsive disorder

Head bandage

Andrew Simpson / Getty Images

Traumatic brain injury (TBI) caused by motor vehicle accidents, falls or other accidents and firearms can cause a wide variety of cognitive issues. In addition to cognitive problems, if you’ve experienced a brain injury, you may also develop symptoms consistent with one or more forms of mental illness including obsessive-compulsive disorder (OCD).

TBI occurs when the brain is injured or damaged by an outside force such as a blow to the head or a gunshot.

TBIs can occur as a closed head injury in which the skull and brain remain intact, like what is seen among professional athletes such as football players, or as a penetrating head injury in which an object penetrates the skull and brain. TBI is often classified according to the severity of injury—mild, moderate or severe.

Common Changes Caused By TBI

If you have experienced a TBI you may also notice a change in your cognitive functioning. After a TBI, your performance on everyday tasks requiring memory, language, spatial or verbal ability may be negatively affected. This can be either temporarily or permanently.

If the TBI affects motor centers within the brain, mobility may also be impaired, and you may need a mobility device like a wheelchair or help with day to day tasks. TBI can also affect your behavior, causing changes in your personality. It is possible, after a TBI, that a previously calm person may become impulsive or aggressive.

Likewise, an outgoing individual may become shy and withdrawn.

TBI and Symptoms of OCD

In addition to changes in cognitive function, behavior, and mobility, TBI can trigger symptoms of OCD including obsessions and compulsions. OCD following a TBI usually occurs soon, if not immediately, after the event has taken place.

However, there have been reports of TBI-induced OCD being diagnosed months after the initial injury. In each case, localized brain damage may or may not be present when viewing a brain scan.

Research has indicated that OCD following a TBI is usually accompanied by symptoms of major depression. Whether this depression is a result of the TBI, the psychosocial stress caused by the injury, the onset of OCD, or a combination of these factors is unclear.

Treating TBI-Related OCD

If you developed OCD after a traumatic brain injury, your doctor may recommend a selective serotonin reuptake inhibitors such as Prozac (fluoxetine) or a tricyclic antidepressant such as Anafranil (clomipramine).

Psychotherapy for OCD following a TBI may also be helpful. However, since cognitive impairment is common among those with TBI, cognitive-based therapies may not be the best option for everyone and should be evaluated on a case by case basis. If you can, choose a supportive therapy which assists you and helps you cope with both the practical and emotional challenges associated with TBI and OCD.

Sources

  • Coetzer, B.R.“Obsessive-compulsive disorder following brain surgery” International Journal of Psychiatry and Medicine 2004 34: 363-377.
  • Grados, M.A. “Obsessive-compulsive disorder after traumatic brain injury” International Review of Psychiatry 2003 15: 350-358.

Source: How OCD and Traumatic Brain Injury Are Linked

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[WEB SITE] OCD linked to inflammation in the brain

 

Woman washing hands OCD
A common symptom of OCD is an obsession with cleanliness.
Obsessive-compulsive disorder is an intrusive condition that remains difficult to treat. This is due, in part, to the causes behind the disorder remaining hidden. Recent research, however, points the finger at brain inflammation.

Obsessive-compulsive disorder (OCD) is characterized by uncontrollable obsessions and compulsions. Individuals with OCD may experience intrusive thoughts that produce anxiety or a need to repeat certain actions to relieve pent-up anxiety.

Common obsessions in OCD revolve around cleanliness, sexual taboos, aggressive thoughts, and symmetry.

Affecting an estimated 1 percent of people in the United States, around half of OCD cases are classed as severe.

OCD is generally treated with talking therapies – in particular, a type of cognitive behavior therapy called exposure and response prevention is recommended. There are also some medications available, with selective serotonin reuptake inhibitors being the most commonly prescribed. Currently, however, therapies only work for around 70 percent of OCD-affected individuals.

One of the biggest stumbling blocks to finding good treatments is that the physical causes of OCD are not known.

Inflammation and OCD

Breaking research published this week in JAMA Psychiatry takes a look at the role of brain inflammation in OCD. The senior author of the study is Dr. Jeffrey Meyer, head of the Neuroimaging Program in Mood & Anxiety at the Centre for Addiction and Mental Health in Toronto, Canada.

Inflammation is a natural process; it is a normal component of the immune response and a standard reaction to injury. However, if the level of inflammation is inappropriate or continues for too long, it can have negative consequences. For instance, in a number of diseases including rheumatoid arthritis and atherosclerosis, inflammation is heavily involved.

Growing evidence suggests that certain psychiatric conditions may involve neuroinflammation, some of which include major depressive disorder, schizophrenia, and bipolar.

Dr. Meyer and his team set out to understand whether inflammation in the brain could play a role in the development of OCD. To this end, they recruited 40 participants, comprising 20 with OCD and 20 without. Each was scanned using positron emission tomography that had been adapted to pinpoint and measure inflammation in the brain.

Specifically, the researchers were able to selectively dye microglia, which are cells that act as the nervous system’s most prominent immune defense and which are activated during inflammation. The researchers measured levels of microglia in six brain regions known to be important in OCD, including the orbitofrontal cortex and anterior cingulate cortex.

The results were clear: in the brain regions associated with OCD, individuals with the disorder had 32 percent more inflammation when compared with people without the condition.

This finding represents one of the biggest breakthroughs in understanding the biology of OCD, and may lead to the development of new treatments.”

Dr. Jeffrey Meyer

From inflammation to treatment

Another interesting finding was that individuals who reported the highest levels of stress when trying to stop themselves from acting on compulsions also had the highest levels of inflammation in a particular brain region.

As so many diseases involve inflammation, there are already a range of drugs designed to tackle it. Because these drugs already exist on the market, it may be a fruitful avenue of research in the hunt for more effective treatments for OCD.

“Medications developed to target brain inflammation in other disorders could be useful in treating OCD,” Dr. Meyer says. “Work needs to be done to uncover the specific factors that contribute to brain inflammation, but finding a way to reduce inflammation’s harmful effects and increase its helpful effects could enable us to develop a new treatment much more quickly.”

Studies are now under way that examine the possibility of designing a blood marker test that could distinguish which patients would benefit most from anti-inflammatory drugs.

Although, as ever, more research is needed, this finding could mark a significant move forward in understanding and treating OCD.

Learn how certain gene mutations can cause OCD-like behaviors.

Source: OCD linked to inflammation in the brain – Medical News Today

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[WEB SITE] This could explain why people with OCD can’t overcome their urges – ScienceAlert

People with obsessive-compulsive disorder (OCD) struggle to overcome their repetitious urges due to an inability to learn what kinds of stimuli are actually safe, new research suggests.

OCD is a disorder where people feel compelled to repeatedly perform certain tasks or think particular thoughts. These insistent routines are called ‘rituals’, and scientists think the behaviours persist because those with OCD struggle to learn when situations aren’t threatening.

“Our study suggests that something is going wrong in the brains of people with OCD when they are learning what is safe, and this in turn affects how they perceive threats under updated circumstances,” says neuroscientist Annemieke Apergis-Schoute from the University of Cambridge in the UK.

Apergis-Schoute and her team conducted a learning experiment where they compared the brain activity and anxiety responses of OCD patients with measurements taken from people without the condition.

OCD is estimated to affect around 1 percent of the adult population in the US, with the disorder compelling people to do things like repeatedly wash their hands, or check that doors are locked and appliances are switched off.

“They’re not usually off-the-wall bizarre,” one of the team, Naomi Fineberg from the Hertfordshire Partnership University NHS Foundation Trust in the UK told New Scientist.

“The obsessions are the sorts of things that most people would understand as being rational but exaggerated – for example, the need to wash your hands after going to the toilet.”

While these rituals aren’t necessarily harmful in themselves, they stem from intrusive and unwanted feelings that are usually associated with anxiety, and can have a considerable impact on carrying out day-to-day activities.

One of the ways of treating OCD is called exposure therapy, where people with the condition are made to confront the source of their anxiety – such as touching a dirty object – in an attempt to control their response.

But exposure therapy doesn’t work for every patient, and even in people who do learn to control their anxiety response, the effectiveness can be limited.

To find out why exposure therapy might only have limited success in treating OCD, the researchers recruited 78 people for a learning experiment – 43 of the volunteers had OCD, and 35 acted as a control group.

Each of the participants were asked to lie in a functional magnetic resonance imaging (fMRI) scanner, which measured their brain activity while they were shown one of two faces – a red face or a green face.

In the first experiment, the participants would receive a mild electric shock when shown the green face, but wouldn’t be shocked when viewing the red.

Sensors that measured tiny amounts of sweat produced by the participants showed that the group learned to associate anxiety with the green face (as a result of the electric shocks that came with it), but not with the red face.

But then the researchers swapped the green and red faces around, so that it was the red face that now came with an electric shock.

While the control group successfully learned the new associations – green is now safe, red is bad – the participants with OCD were less able to register that the green face no longer posed a threat.

Measurements of the participants’ brain activity when they were shown the now safe green face indicated that the OCD patients had less activity in the ventromedial prefrontal cortex – which is associated with processing safety signals in the brain, and decision making in relation to perceived risks.

According to the researchers, this could explain why people with OCD have difficulty overcoming their rituals, because their brains may find it significantly harder to unlearn negative associations, even when treatment such as exposure therapy attempts to directly counter them.

“This needs to be taken into consideration when we’re developing future therapies to tackle the disorder,” Apergis-Schoute explains in a press release.

“Current exposure therapies may help the patient take control over their compulsions, but our work suggests that they might never learn that their compulsions are unnecessary and they may return in times of stress.”

It’s worth pointing out that the researchers are drawing their conclusions from a very small sample of participants, so larger studies involving more patients affected by OCD will be needed to confirm the findings.

But if the results can be replicated, it could help explain some of the limitations of exposure therapy, and improve the delivery of the treatment in the future.

“The bit of their brain that should be telling them it’s safe isn’t working,” Fineberg explained to Clare Wilson at New Scientist.

“Now we can say to them this is why [exposure therapy is] taking so long and we should stick with it.”

The findings are reported in PNAS.

Source: This could explain why people with OCD can’t overcome their urges – ScienceAlert

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