Obsessive compulsive disorder Flashcards
What is OCD?
Obsessive Compulsive Disorder (OCD) is a mental health condition that is diagnosed in individuals who experience disruption to their daily functioning as a result of obsessions and/or compulsions
Roughly, how many people have OCD?
About 2% of the population at some point in their lives
What must someone experience to be diagnosed with OCD?
They must experience clinically significant distress or impairment in functioning on most days for a period of two weeks or more
What are the cognitive characteristics of OCD?
- Obsessive thoughts
- Hypervigilance
- Irrational thoughts, including catastrophic thinking
What are the behavioural characteristics of OCD?
Compulsions
What are the emotional characteristics of OCD?
- Anxiety
- Guilt
- Disgust
What does the genetic explanation state about OCD?
The genetic explanation states that OCD is inherited
What do genetic explanations focus on?
Identifying candidate genes
What are the 2 genes that have been linked with OCD?
COMT and SERT
What is the COMT gene responsible for?
Clearing dopamine from synapses and low activity of the COMT gene is associated with OCD - this suggests that high levels of dopamine activity is associated with OCD
What happens if COMT fails to clear dopamine from the synapses?
The person will focus on the one thought, which then becomes an obsession
What is the SERT gene responsible for?
The SERT gene (also known as the 5-HTT gene) affects the transport of serotonin (hence SERontonin Transporter), causing lower levels of serotonin which is also associated with OCD (and depression)
What does serotonin do?
Serotonin regulates mood - lower levels of serotonin are associated with mood disorders, such as depression
Where does the support for the role of serotonin in OCD come from?
Research examining anti-depressants, which have found that drugs which increase the level of serotonin are effective in treating patients with OCD
What is the neural explanation of OCD?
The OFC converts sensory information into thoughts and actions.
Heighted activity in the OFC generates ‘worry messages’ = obsessions
These ‘worries’ are sent to the basal ganglia which is responsible for facilitating wanted behaviours and stopping unwanted behaviours.
This ‘filter’ is faulty in OCD so worries are passed on to the thalamus which sends signals to the motor cortex (where movements are controlled). The thoughts are converted in to actions = compulsions.
According to the neural explanation why are behaviours repeated?
In OCD, completion of the structured event complex relieves anxiety
What evidence is there to support the neural explanation?
- Evidence shows that the correlations between cortical brain activity and basal ganglia brain activity are different in people with OCD and healthy individuals. Furthermore, OCD symptoms can also be improved in humans by stimulating a part of the basal ganglia.
- Patients who suffer head injuries in this region often develop OCD-like symptoms, following their recovery. Furthermore, Max et al (1994) found that when the basal ganglia is disconnected from the frontal cortex during surgery, OCD-like symptoms are reduced, providing further support for the role of the basal ganglia in OCD.
- PET scans have found higher activity in the OFC in patients with OCD.
What are the implications of the neural explanation?
While we like to think we are in control of our thoughts and behaviours, this explanation suggests that we do not.
This approach views the brain as a biological computer and suggests that we do not have free will
What does SSRIs stand for?
Selective serotonin reuptake inhibitors
What do SSRIs do?
Selective serotonin reuptake inhibitors (SSRIs) are used to treat the symptoms of OCD by increasing serotonin activity at the synapse
How do SSRIs work?
SSRIs prevent the reabsorption and breakdown of serotonin by blocking presynaptic transporter molecules. This causes serotonin to remain active in the synaptic cleft where it is able to repeatedly bind to receptors on the membrane of the post-synaptic neuron. This means that this neuron is repeatedly stimulated and the transmission of mood-related information is increased.
This compensates for the dysfunction in the serotonergic pathways that may be causing the symptoms of OCD
When using SSRIs when do symptoms generally start to improve?
SSRIs cause an immediate increase in serotonin activity but an improvement to symptoms is most often only seen after 12 weeks of taking the medication
How has it been suggested that the improvement in symptoms from SSRIs is a result of down-regulation?
The brain compensates for the increased serotonin by reducing the amount that is released from the presynaptic neuron
What evidence is there to support the effectiveness of SSRIs?
Issari (2016) carried out a meta-analysis of 17 studies and found a significantly greater improvement in patient’s symptoms in the groups after taking SSRIs compared with the placebo group. This research demonstrates that SSRIs, a relatively cheap and low-effort treatment, can provide relief for some people with OCD
What are the issues with SSRIs as a treatment for OCD?
- Can causes unpleasant side effects - dizziness, sleeping problems, headaches, agitation and anxiety, and in some cases cause suicidal thoughts or urges to self-harm
- Up to 60% of people report no improvement in the symptoms after taking drug treatments like SSRIs
- For those who do experience relief, the reduction in symptom severity ,ay only be between 20-30%
What are alternative treatments for OCD?
Most patients with mild OCD will be offered a type of cognitive behavioural therapy (CBT) with exposure and response prevention (ERP)
As a treatment of OCD, what is CBT based on?
This treatment is based on the assumptions of the cognitive approach, that OCD is caused by dysfunctional thought processes
