The biological approach to explaining and treating OCD Flashcards
What do genetic explanations suggest about the cause of OCD?
OCD is partly inherited through faulty versions of specific genes that affect neurotransmitter levels
What role does the COMT gene play in OCD?
The faulty COMT gene leads to too much dopamine, which is linked to OCD symptoms
How does the SERT gene relate to OCD?
A faulty SERT gene leads to too little serotonin, a neurotransmitter involved in mood regulation
How are genetic and neural explanations of OCD connected?
Faulty genes cause neurotransmitter imbalances, which affect brain circuits related to OCD symptoms
What is meant by a “faulty worry circuit” in OCD?
Abnormal functioning in brain areas like the orbitofrontal cortex (OFC) and thalamus results in heightened anxiety and compulsions
What is the role of the orbitofrontal cortex (OFC) in OCD?
It sends signals about potential threats; overactivity can lead to obsessive worry
What is the role of the thalamus in OCD?
It is involved in the relay of sensory and motor signals; dysfunction contributes to repeated behaviours
How is serotonin involved in OCD?
Low levels of serotonin are linked to the inability to regulate mood and anxiety, contributing to OCD symptoms
What is the main aim of SSRI treatment for OCD?
To increase the levels of serotonin in the brain
How do SSRIs work?
They block the reuptake of serotonin at the presynaptic neuron, allowing it to remain longer in the synapse
Why is understanding how SSRIs work important?
Must know they increase serotonin by blocking its reabsorption, improving its action at the synapse
What is an example of an SSRI used to treat OCD?
Fluoxetine
What are common side effects of SSRIs?
Nausea, headaches, sleep problems, and sexual dysfunction
How do Tricyclic antidepressants differ from SSRIs?
They work similarly by increasing serotonin but also affect noradrenaline levels
What is the role of benzodiazepines (BZs) in OCD treatment?
They enhance GABA activity, producing a calming effect by reducing neuron excitability
Why might drug treatments like SSRIs not work for everyone?
Because OCD may have multiple causes, including environmental and cognitive factors
How can drug therapy be evaluated positively?
It’s cost-effective, non-disruptive, and effective for many patients
What is a potential limitation of drug therapy?
It may only treat symptoms, not the root cause, and can cause relapse if medication is stopped.
How do obsessions and compulsions differ in terms of characteristics?
Obsessions are cognitive (intrusive thoughts); compulsions are behavioural (repetitive actions to reduce anxiety)
Example of a compulsion and obsession in OCD?
Obsession: fear of parents dying
Compulsion: switching lights on/off 10 times to prevent it
What are the FIVE stages of synaptic transmission? (1)
Action Potential Arrives - an electrical impulse (action potential) travels down the axon of the presynaptic neuron and reaches the axon terminal
What are the FIVE stages of synaptic transmission? (2)
Vesicles Release Neurotransmitters - The arrival of the action potential triggers calcium ion channels to open.
Synaptic vesicles move toward the presynaptic membrane and release neurotransmitters into the synaptic cleft
What are the FIVE stages of synaptic transmission? (3)
Neurotransmitters Cross the Synaptic Cleft - The neurotransmitters diffuse across the synaptic gap (cleft) between the presynaptic and postsynaptic neurons
What are the FIVE stages of synaptic transmission? (4)
Neurotransmitters Bind to Receptors - Neurotransmitters bind to specific receptor sites on the postsynaptic membrane.
This can lead to either excitation (increasing the chance of a new action potential) or inhibition (decreasing the chance)
