OCD: explaining and treating (Biological approach) - Psychopathology [A-Level Psychology]

Summary

This script delves into the biological aspects of OCD, a condition often misunderstood as mere tidiness. It clarifies OCD's debilitating nature with intrusive thoughts and compulsions, and explores its genetic roots, candidate genes, and neural mechanisms involving serotonin. The video also evaluates treatments, emphasizing SSRIs' effectiveness and the potential role of environmental factors, suggesting a combination of biology and environment in OCD's development.

Takeaways

• 🧠 OCD is a mental health condition that is often misunderstood; it is not merely about being tidy or organized.
• 🤔 The condition is characterized by intrusive thoughts and repetitive behaviors that cause significant distress and anxiety.
• 🧬 There is a genetic component to OCD, with certain 'candidate genes' being more common in affected individuals.
• 👨‍👩‍👧‍👦 Family studies show a higher prevalence of OCD among first-degree relatives, suggesting shared genetic factors.
• 🧬👭 Identical twins have a higher concordance rate for OCD than non-identical twins, indicating a strong genetic influence.
• 🧪 The serotonin system in the brain, particularly the SERT gene, is implicated in the development of OCD.
• 💊 SSRIs are a common pharmacological treatment for OCD, working by increasing serotonin levels in the brain.
• 🧠🔄 The 'worry circuit' in the brain, involving areas like the orbito-frontal cortex and basal ganglia, is overactive in OCD.
• 🔍 Neuroimaging studies have shown hyperactivity in certain brain regions associated with OCD.
• 🌐 The diathesis-stress model suggests that a genetic predisposition to OCD may require an environmental stressor to manifest.
• 💊💰 Drug therapy for OCD is generally less expensive and more accessible than psychological therapies like CBT.

Q & A

What is OCD and why is it often misunderstood?

OCD, or obsessive-compulsive disorder, is a mental health condition characterized by repetitive and intrusive thoughts causing anxiety, and the need to perform behavioral compulsions. It's often misunderstood because people casually attribute the term to individuals who are exceptionally organized or prefer routine, which minimizes the severity of the actual disorder.

How do the symptoms of OCD manifest?

Symptoms of OCD include obsessive thoughts, which are mental images, worries, or urges that cause anxiety, and compulsions, which are behaviors performed to temporarily relieve the anxiety caused by these thoughts. Common obsessions include fears of dirt leading to excessive cleaning, concerns about burglary leading to repeated checking of locks, and worries about causing a fire leading to repeated checking of power switches.

What is the genetic explanation for OCD?

The genetic explanation suggests that a predisposition to OCD is inherited. While there isn't a single 'OCD gene', there are 'candidate genes' like the gene 9, COMT gene, SERT gene, and 5HT1-D beta gene that are more frequently found in individuals with OCD. OCD is considered polygenic, with up to 230 genes potentially involved.

How do family studies support the genetic origin of OCD?

Family studies indicate a higher prevalence of OCD among first-degree relatives of individuals with OCD, known as the concordance rate, which rises to 10% compared to 2% in the general population. Identical twins (monozygotic twins) have a 68% concordance rate for OCD, while non-identical twins (dizygotic twins) have a 31% rate, suggesting a genetic component.

What is the role of neurotransmitters in OCD?

Neurotransmitters, particularly serotonin, play a key role in OCD. Low levels of serotonin are thought to cause obsessive thoughts, potentially due to it being removed too quickly from the synapse before it can transmit its signal. The SERT gene, responsible for serotonin transportation in the synapse, is implicated.

What brain structures are involved in the neural explanation of OCD?

The 'worry circuit' in the brain, which includes the orbito-frontal cortex, the basal ganglia (specifically the caudate nucleus), and the thalamus, is overactive in people with OCD. This overactivity leads to an inability to filter out small worries, resulting in recurring obsessive thoughts.

How do evaluations of genetic factors in OCD consider environmental influences?

Evaluations consider the diathesis-stress model, suggesting individuals inherit a genetic vulnerability (diathesis) to OCD, but the disorder develops only with an environmental stressor, such as a traumatic life experience. This is supported by research showing a correlation between traumatic life events and increased severity of OCD symptoms.

What is the effectiveness of drug therapies like SSRIs in treating OCD?

SSRIs, or selective serotonin reuptake inhibitors, are antidepressant drugs used to control OCD symptoms by normalizing the activity of the worry circuit. A meta-analysis by Soomro showed SSRIs to be more effective than placebos, suggesting a biological aspect to OCD treatment.

What are the limitations of drug therapies for OCD?

Drug therapies like SSRIs may not be effective for all patients, can take up to three to four months to impact symptoms, and may only treat symptoms rather than the cause. Additionally, they can have side effects and there is criticism regarding the reliability of research funded by pharmaceutical companies.

Why might psychological therapies like CBT be preferred over drug therapy for some OCD patients?

Psychological therapies like CBT (Cognitive Behavioral Therapy) may be preferred as they potentially address the root cause of OCD rather than just the symptoms. They can be more effective in the long term, despite being more expensive and time-consuming than drug therapies.

What economic factors influence the choice between drug therapy and psychological therapies for OCD?

Drug therapy is often chosen over psychological therapies like CBT due to its relatively lower cost and convenience. However, the potential for side effects and the possibility of only treating symptoms rather than the cause may influence some patients to opt for psychological therapies despite their higher cost.

Outlines

00:00

🧠 Understanding OCD: The Biological Perspective

Obsessive-Compulsive Disorder (OCD) is a common yet misunderstood mental health condition characterized by intrusive thoughts and repetitive behaviors. Contrary to casual references to tidiness or preference for order, OCD is a serious illness causing significant anxiety and disruption to daily life. This video aims to explore the biological basis of OCD, including genetic factors, brain structure involvement, and neurotransmitter imbalances. It discusses how the condition is not merely a personality trait but a complex disorder affecting brain areas such as the orbito-frontal cortex, basal ganglia, and thalamus. The video also touches on the genetic predisposition to OCD, mentioning candidate genes like the SERT gene and the role of serotonin in the disorder.

05:00

🧬 Genetic and Neural Bases of OCD

The genetic explanation for OCD suggests a hereditary component, with certain genes such as gene 9, COMT, SERT, and 5HT1-D beta gene being more prevalent in individuals with OCD. OCD is considered polygenic, with up to 230 genes potentially involved. Family and twin studies support a genetic link, showing higher concordance rates among relatives and identical twins. The video also delves into the neural aspects, highlighting the 'worry circuit' involving the orbito-frontal cortex, basal ganglia, and thalamus. This circuit's hyperactivity is linked to the obsessive thoughts and compulsive behaviors seen in OCD. Additionally, the parahippocampal gyrus, responsible for regulating emotions, is noted for its abnormal function in OCD cases.

10:00

💊 Evaluating Biological Treatments for OCD

The video evaluates the biological approach to treating OCD, focusing on the effectiveness of drug therapies. It discusses the use of SSRIs, such as Fluoxetine, which are designed to increase serotonin levels in the brain and normalize the activity of the 'worry circuit.' While SSRIs have shown to be more effective than placebos in reducing OCD symptoms, they may take weeks to have an effect, and some patients do not respond fully. The video also addresses potential side effects and the limitations of drug therapy, such as the possibility of treating only symptoms rather than the root cause. It raises concerns about the reliability of research funded by pharmaceutical companies and the potential for environmental factors, such as traumatic life events, to play a role in OCD's development and severity.

Keywords

💡OCD

OCD stands for Obsessive-Compulsive Disorder, a mental health condition characterized by intrusive, repetitive thoughts (obsessions) and the urge to perform repetitive behaviors (compulsions). In the video, OCD is discussed as a serious condition that is often misunderstood in popular culture, where it is sometimes casually attributed to simply being tidy or organized. The script clarifies that OCD is much more debilitating, causing significant anxiety and interfering with daily life.

💡Obsessions

Obsessions refer to the persistent, unwanted thoughts, images, or urges that cause anxiety in individuals with OCD. The video script explains that these obsessions can revolve around various themes such as dirt, causing harm, or symmetry, and they dominate the individual's mental world, leading to significant distress.

💡Compulsions

Compulsions are the repetitive behaviors that a person with OCD feels driven to perform in response to an obsession. The script mentions behaviors such as excessive cleaning, checking locks repeatedly, or flipping switches multiple times. These compulsions are aimed at reducing the anxiety caused by obsessions but only provide temporary relief.

💡Genetic predisposition

Genetic predisposition implies that a person's susceptibility to a condition, such as OCD, is influenced by their genetic makeup. The script discusses how certain genes, known as candidate genes, are more frequently found in individuals with OCD, suggesting a genetic component to the disorder.

💡Candidate genes

Candidate genes are specific genes that are hypothesized to be associated with a particular disease or condition, like OCD. The video mentions genes such as the 9, COMT, SERT, and 5HT1-D beta genes as examples of candidate genes that might be linked to OCD, indicating that the disorder is polygenic, involving multiple genes.

💡Polygenic

Polygenic refers to a condition being determined by multiple genes. In the context of the video, OCD is described as polygenic, meaning it is influenced by a combination of genetic factors rather than a single gene, which complicates the understanding of its heritability.

💡Neurotransmitters

Neurotransmitters are chemical messengers that transmit signals across a synapse from one neuron to another. The script highlights serotonin as the neurotransmitter most associated with OCD, suggesting that imbalances in serotonin levels may contribute to the development of the disorder.

💡Serotonin

Serotonin is a neurotransmitter that plays a crucial role in regulating mood, anxiety, and other functions. The video explains that low levels of serotonin, possibly due to its rapid reuptake, are thought to be linked to obsessive thoughts in individuals with OCD.

💡Worry circuit

The 'worry circuit' is a term used in the script to describe a set of brain structures involved in OCD, including the orbito-frontal cortex, basal ganglia (specifically the caudate nucleus), and the thalamus. Overactivity in this circuit is suggested to lead to an inability to filter out minor worries, contributing to obsessive thoughts.

💡SSRIs

SSRIs, or selective serotonin reuptake inhibitors, are a class of antidepressant drugs used to treat OCD by increasing the availability of serotonin in the brain. The script explains that SSRIs work by blocking the reuptake of serotonin, thus normalizing the activity of the worry circuit and reducing anxiety.

💡CBT

CBT stands for Cognitive Behavioral Therapy, a type of psychological treatment that helps patients identify and change negative thought patterns and behaviors. The video script contrasts drug therapy with CBT, noting that while drug therapy may be more accessible, CBT might be a more effective long-term solution for treating OCD.

Highlights

OCD is often misunderstood and trivialized by associating it with being exceptionally organized or tidy.

OCD sufferers experience repetitive and intrusive thoughts that cause constant anxiety.

The need to repeat behavioral compulsions leaves little time for other aspects of life.

Biological approaches to OCD include explanations from genetics and neural mechanisms.

OCD is common, affecting around one in fifty people.

Obsessions are mental images, worries, or urges that cause anxiety.

Compulsions are behaviors performed to relieve discomfort caused by obsessive thoughts.

Common obsessions include dirt and contamination, burglary, and causing a fire.

Genetic predisposition plays a role in OCD, with candidate genes like gene 9, COMT, SERT, and 5HT1-D beta gene.

OCD is polygenic, involving up to 230 separate genes.

Family studies indicate a genetic origin to OCD, with a higher concordance rate among first-degree relatives.

Monozygotic twins have a higher concordance rate for OCD than dizygotic twins.

Candidate genes may influence the functioning of neural systems, particularly the serotonin system.

Neurotransmitter imbalances, particularly of serotonin, are implicated in OCD.

The 'worry circuit' in the brain is overactive in OCD, leading to an inability to filter out small worries.

The parahippocampal gyrus, responsible for regulating unpleasant emotions, is linked to OCD.

Genetic studies suggest a genetic origin to OCD, but environmental factors may also play a role.

The diathesis-stress model proposes that a genetic vulnerability to OCD may require an environmental stressor to develop.

Neuroimaging studies show hyperactivity in the OFC and caudate nucleus in people with OCD.

SSRIs are effective in treating OCD symptoms, but their mechanism suggests that serotonin levels are not the sole cause.

SSRIs work by inhibiting serotonin reuptake, increasing its effectiveness in the synapse.

Drug therapy is more accessible and less expensive than psychological therapies like CBT.

Research by Soomro shows SSRIs significantly reduce OCD symptoms compared to placebos.

Critics argue that research on drug therapies may be biased due to pharmaceutical company funding.

Drug therapy may only treat symptoms and not the cause of OCD.

Psychological therapy may be a more effective long-term treatment for OCD.

Transcripts

OCD is a fairly well-known, but also a very misunderstood mental health condition, often

people who are exceptionally organised and tidy, or like to do things a certain way will

say, oh I’m a bit OCD.

But that's simply not true.

That kind of comment minimises how badly people with obsessive-compulsive disorder suffer

from their illness.

Repetitive and intrusive thoughts dominate the internal mental world of someone with

OCD causing constant and crippling anxiety.

The need to repeat the same behavioural compulsions, again and again, leaves little time for the

rest of your life.

In this video, we will discuss the biological approach to explaining, and treating OCD.

Of course, if you want to brush up on biological terminology, you can check out my biological

psychology video in the approaches unit, but I will cover everything you need for this

section, from the areas of the brain to candidate genes and drug treatments, as well as evaluations

right here.

The biological approach to explaining and treating OCD

reword each paragraph in the style of a knowledgeable expert, and keep paragraphs numbered

You likey remember what obsessive-compulsive disorder is from my characteristics video,

but as a quick reminder, OCD is a common mental health condition affecting around one in fifty

people, these individuals have obsessive thoughts and compulsive behaviours.

The repetitive and unpleasant obsessive thoughts are mental images, worries or urges that cause

anxiety.

The compulsion are the behaviours that the individual feels they need to act out to relieve

discomfort caused by the obsessive thought, unfortunately, this relief is only temporary,

and the obsessive thoughts soo n return

Obsessions around dirt and contagon are common, leading to repetitive cleaning, there are

obsessions about burglary, leading to repetitive checking of locks, and obsessions about causing

a fire, leading to repetitive checking of power switches.

These are just some of the more common symptoms, but there are many many other obsessions and

compulsions.

There are a range of explanations for why people develop OCD, but in this video we need

to focus on the biological, including genetic and neural explanations

The biological approach to explaining OCD: the genetic explanation

The Genetic explanation suggests that a vulnerability or predisposition to OCD is inherited from

our parents, while there certainly isn't one single OCD gene that causes OCD, there are

some individual genes, called candidate genes that are found more frequently in those people

who have OCD, these include gene 9, COMT gene, SERT gene and 5HT1-D beta gene.

However in total there are as many as 230 separate genes that could be involved in some

way in the development of OCD, this means OCD is polygenic.

Family studies also indicate a genetic origin to OCD, the prevalence rate of OCD in the

general population is 2%, however if an individual has OCD, the likelihood that their first degree

relatives, has OCD, known as the concordance rate, rises to 10%, this increased risk is

arguably due to shared genetics, with first degree relatives sharing 50% of their genes.

Identical twins, who share 100% of their genetic makeup, also known as monozygotic twins have

been shown to have a 68% concordance rate for OCD, while non identical, or dizygotic

twins have a 31% concordance rate.

The presence of genes isn't the whole story, because these genes have functions, the role

of your genes is to code for aspects of your biology, and it's thought these candidate

genes might influence the functioning of certain neural systems in your brain, especially the

serotonin system.

The biological approach to explaining OCD: the neural explanation.

Neural explanations for OCD include both biochemical causes, this is an imbalance of neurotransmitters,

chemicals that communicate information between neurons, and the large structures in the brain

that are made of many neurons.

Serotonin is the neurotransmitter most associated with OCD.

Low levels of serotonin is thought to cause obsessive thoughts, and the low level of serotonin

is likely due to it being removed too quickly from the synapse, before it has been able

to transmit its signal.

If you haven't studied neurons and synapses yet, that probably sounded like a pretty weird

sentence, when it comes to synapse and synaptic transmission, I’m going to tell you what

you need to know for OCD in this video, but I did make an entire video on synapses you

may want to watch..

Serotonin and other neurotransmitters are chemical messengers, presynaptic neurons release

neurotransmitters, these are detected by receptors on the postsynaptic neuron, if the signal

is strong enough then the message is passed on, the neurotransmitters detach from the

receptors are taken back to the presynaptic neuron through a process called reuptake.

It seems this process happens too quickly in people with OCD, leading to reduced levels

of serotonin in the synapse.

The SERT gene mentioned in the previous section is the gene responsible for serotonin transportation

in the synapse.

Looking at the larger structures in the brain, the communication between a set of brain structures

termed the “worry circuit” is overactive in people with OCD, leading to an inability

to filter out small worries.

The structures that forms the worry circuit are the orbito-frontal cortex, the part of

the brain responsible for rational decision making, the basal ganglia system, in particular

a part called the caudate nucleus, and the thalamus.

In normal functioning the basal ganglia filters out minor worries coming from the orbito-frontal

cortex, but if this area is hyperactive even small worries get to the thalamus, which are

then passed back to the OFC forming a loop, this is the recurring obsessive thoughts.

This abnormal activity is ultimately responsible for the repetitive motor functions, the compulsions,

these are an attempt to break this loop.

While carrying out the compulsion may give temporary relief, the hyperactive basal ganglia

will soon resume the worry circuit.

There is another brain area linked to OCD called the parahippocampal gyrus, its an area

of cortex on the underside of the brain, close to the hippocampus, its responsible for regulating

and processing unpleasant emotions, and has been seen to function abnormally in cases

of OCD.

The biological approach to explaining OCD: Evaluations

The fact that there is a high concordance rate between close family members, shown by

the data provided by Nestadt, suggests that there is a genetic origin to OCD.

Closer relations share more DNA, and have a higher concordance rate, this is because

if you share more DNA you have a higher chance of sharing the parts of DNA that causes OCD.

Both MZ and DZ twins grow up sharing very similar environments like food, upbringing

and education, and life events like bereavement or parental divorce.

But there is a significant difference in concordance rate, 68% MZ and 31% DZ, suggesting its the

additional shared DNA is what’s responsible for the increased concordance.

But as you can imagine, there are issues with assuming its the DNA that results in the high

concordance rates, closer family members also share similar environments, and even when

it comes to twins, who do have similar experiences, it could be argued that identical monozygotic

twins are treated more similarly, on the basis that they look identical, compared to dizygotic,

non identical twins.

Also the concordance rate even for identical twins at 68%, is not 100%, the level we would

expect for a feature that was entirely genetically determined, so there is likely a role for

the environment.

This means the diathesis stress model may be a more valid explanation than biology alone,

individuals inherit a genetic vulnerability to OCD, a diathesis, however the disorder

does not develop unless there is a stressor, an environmental factor such as a traumatic

life experience.

This is supported by research from Cromer, who showed 54% of 265 participants with OCD

reported at least one traumatic life event, and those with traumatic life events reported

increased severity of OCD symptoms, this demonstrates an environmental aspect to OCD.

A number of neuroimaging studies using PET scanners have shown hyperactivity in the OFC

and the caudate nucleus in people with ocd both while scanning the brain at rest and

when symptoms are stimulated, but there is a problem with this neural evidence, it is

correlational, researchers cannot be sure if the hyperactivity in these areas are the

cause of OCD, or a consequence of having OCD.

We can evaluate the biological explanation for OCD based on the effectiveness of drug

therapies, A meta-analysis by Soomro demonstrated SSRI’s are more effective than placebos,

suggesting there is a biological aspect to OCD, however despite altering levels of serotonin

in the synapse within hours, these drugs take weeks to reduce symptoms and 40% to 60% of

patients show no or just partial symptom improvement.

These findings suggest low levels of serotonin have a role to play in OCD, but are not the

sole cause of OCD.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3181958/

The main type of drug used to control the symptoms of OCD are a group of antidepressant

drugs called SSRIs, one example is Fluoxetine, also known as prozac.

I think these SSRI’s are really well named because the name explains exactly what this

class of drugs do in the brain, they are selective serotonin, meaning they only influence serotonin

in the brain, reuptake inhibitors, meaning they inhibit, so slow down the process of

reuptake in the synapse this means the serotonin continues to stimulate the postsynaptic neuron.

This decreases anxiety by normalising the activity of the worry circuit.

Going back to this image, we can see the process of reuptake, SSRI’s by blocking the reuptake

of serotonin, keep serotonin in the synapse for longer, increasing its effectiveness.

It can take three to four months for SSRIs to impact symptoms, however for some patients

SSRIs are not effective, the dosage can be increased, or there are other treatment options,

anti-anxiety drugs like benzodiazepines enhance a neurotransmitter called GABA, slowing the

central nervous system resulting in general relaxation.

Tricyclics and SNRIs work by increasing serotonin and noradrenaline; these drugs can be effective

when SSRIs fail, but because they work on multiple neurotransmitters, they tend to have

more intense side effects.

Evaluations of biological treatments for OCD

There is research evidence by Soomro that compared SSRI’s to placebos, placebos are

sugar pills that make the patient think they are receiving drug therapy.

Soomro combined the data from 17 studies, including 3097 participants into a meta-analysis.

The results showed that SSRI’s significantly reduced the symptoms of OCD placebos between

6 and 17 weeks post treatment.

This suggests drug therapy is effective, at least in the short term.

There are criticisms that this type of research may not be as reliable as it appears, Goldacre

points out that the vast majority of the research studies on drug therapies are conducted by

the pharmaceutical companies who created them.

This means they have a financial interest in showing they are effective, this along

with the file drawer problem, the fact that many negative results stay unpublished, means

that drug therapies may not actually be as effective as drug companies claim they are.

On a related point, Dr Ben Goldacre has two book’s Bad Science and Bad Pharma.

They are interesting and well written, any student considering medicine, or just interested

in how science is conducted poorly and misrepresented in the media should read them.

economics of drug therapy and alternatives An advantage of drug therapy is its a relatively

inexpensive treatment, as well as potentially more convenient for the patient, this is in

comparison to psychological therapies like CBT, which require multiple sessions with

a trained therapist, as CBT is much more expensive, from an economic perspective health services

like the NHS are more likely to provide drug therapy before CBT.

A disadvantage of drug therapy is it is not the preferred treatment plan for many patients,

with many preferring a course of cognitive behavioural therapy, this is because drug

therapy can have a range of potential side effects, in the Soomro meta-analysis Nausea,

headache and insomnia were the most common side effect for each drug tested.

There are other reasons drug therapy are not preferred by patients, the desired effects

of the drugs, the symptom reduction can take up to three to four months and patients can

ultimately become dependent on the drugs.

And finally, drug therapies may actually be only treating the symptoms of OCD, not the

cause, serotonin imbalance could be due to other biological processes, or the origin

of OCD may not be biological at all, but be due to a traumatic experience.

Remember research by Cromer showed 54% of 265 participants with OCD reported at least

one traumatic life event, and those with traumatic life events reported increased severity of

OCD symptoms.

This suggests drug therapy may only be a temporary solution, and psychological therapy may be

a more effective long term treatment.