Lesson 13: The biological approach to treating OCD: Drug Therapy Flashcards
What is seretonin and what does it do
Serotonin is a neurotransmitter thought to inhibit aggressive responses to emotional stimuli and increase self-control. Low levels of serotonin are associated with increased susceptibility to impulsive behaviour, aggression and violent suicide, and a general lack of self-control.
• Selective Serotonin Re-uptake Inhibitors examples include Prozac and Fluoxetine
• Low levels of serotonin are associated with OCD and depression.
What do SSRI drugs do
• SSRI drugs aim to prevent the reuptake of serotonin and prolong its activity in the synapse. This means the person will feel less anxious and have a higher level of serotonin available.
What is a synapse
the junction between two neurons where information is transmitted from one neuron to another.
What is the caudate nucleus and how does seretonjn affect it
• Low levels of serotonin are implicated in the, “worry circuit” whereby damage to the caudate nucleus in the brain fails to suppress minor worry signals.
The caudate nucleus helps process visual information and control movement. It’s involved in working memory, cognitive function, and emotions. The structure plays a vital role in how the brain learns, specifically the storing and processing of memories
What is the orbital front context
• A message is then sent to the orbital frontal cortex and the worrying and anxiety get worse.
The orbitofrontal cortex is an important region of the brain involved in the processing of rewards and punishments. It receives and integrates inputs from all the sensory modalities: taste, smell, somatosensory, auditory and visual, as well as visceral sensory and visceral motor information.
Why are drugs given to OCD patients
• Therefore drugs are given to OCD patients that will increase serotonin levels and help to regulate mood and reduce anxiety levels.
• Increasing serotonin via SSRI drugs will also help to normalize ad reduce the “worry circuit”
• High levels of serotonin provided by SSRI drugs help the orbital frontal cortex to function at normal levels.
• SSRI drugs will help stabilize moods and emotions and improve memory (therefore will reduce compulsive behaviour and checking).
• SSRI drugs are prescribed for 12-16 weeks
What are SNRI drugs
• SNRI (Selective Norepinephrine Reuptake Inhibitors) are a new type of drug that increase serotonin and noradrenaline/norepinephrine. These drugs are suitable for OCD patients that cannot tolerate SSRI drugs
• Norepinephrine/noradrenaline is a neurotransmitter released from the sympathetic nervous system in response to stress. It aims to mobilize the brain and body for action. SNRI’s act on the reuptake of noradrenaline/norepinephrine.
Strengths of SSRI for ocd
1) There is supporting evidence that SSRI’s are an effective treatment for OCD. Soomro (2009) reviewed 17 studies that compared SSRI’s to placebo drugs for treating OCD and found that all 17 studies showed that SSRI drugs were more effective than placebos, especially when SSRI’s were combined with CBT (+)
2) An advantage of SSRI drugs is that they are relatively effective and 70% of patients have experienced a decline in OCD symptoms when taking them. However, the remaining 30% of patients tend to opt for psychological therapies or a combination of SSRI’s and psychological therapies for treating their OCD, which meant that maybe SSRI drugs are most effective if combined with other treatments too? (+) (-)
3) SSRI’s have the benefit of being relatively cheap and cost effective in comparison to psychological therapies, such as CBT, counselling or family therapy. Using SSRI drugs to treat OCD is good value for money for the NHS, and is economical compared to other treatments (+)
Weakness of SSRI for ocd
4) SSRI’s can be criticised because they do not work for all OCD patients. For some patients SSRI drugs will not alleviate their OCD symptoms and they will have to take an alternative drug such as tricyclics instead which might be more effective for them (-)
5) A problem with SSRI drugs is that they have terrible side effects which might mean that the OCD patient might stop taking the medication. Side effects are temporary but include indigestion, blurred vision and loss of sex drive. (-)
6) Koran (2007) has criticised the use of drugs and medication to help relieve OCD symptoms. Koran stated that drug therapy might be a common or popular treatment, but psychotherapies such as CBT should be tried first to help reduce OCD symptoms. Drug therapy requires little effort and may be effective short term, but it does not provide a lasting cure for OCD, and many patients relapse within a few weeks if the medication is stopped. (-)
What are BZ drugs
• BZ drugs reduce anxiety and aim to control the action of neurotransmitters.
• Examples of BZ drugs include Valium and Xanax.
• BZ drugs reduce the activity in the central nervous system and reduce brain arousal.
What is CNS made of
The central nervous system is made up of the brain and spinal cord: The brain controls how we think, learn, move, and feel. The spinal cord carries messages back and forth between the brain and the nerves that run throughout the body.
How do BZ drugs work
• BZ aim to reduce blood pressure and reduce heart rate
• BZ aim to increase GABA (Gamma-Amino butyric Acid).
• GABA is a neurotransmitter in the brain that slows down the firing of neurons and makes the person less anxious and calmer. It helps to reduce physiological activity in the body.
• BZ drugs bind to the GABA receptor site of the post synaptic neuron. This increases the flow of chloride ions into the post synaptic neuron. The chloride ions make it more difficult for the neuron to be stimulated by other neurotransmitters, thus slowing down its activity and making the person feel more relaxed.
• Neurons in the brain become less active and the person feels calmer.
• BZ help to reduce the anxiety that an OCD patient might experience when they are having their obsessional thoughts.
• BZ also decreases serotonin levels in the brain. This means that the person has lower arousal and reduces anxiety, but they are less happy and are more likely to get depressed!
What is a post synaptic neurone
A presynaptic neuron transmits the signal toward a synapse, whereas a postsynaptic neuron transmits the signal away from the synapse. The transmission of information from one neuron to another takes place at the synapse, a junction where the terminal part of the axon contacts another neuron.
Strength of BZ drugs
1) A strength of BZ drugs is that they are very effective at reducing anxiety and OCD symptoms. They are used by millions of people worldwide, so they are very good at reducing anxiety and OCD on a global basis (+)
2) BZ drugs have the advantages that they work very quickly and effectively to cure OCD symptoms compared to other psychological treatments (such as CBT). BZ drugs can begin to reduce anxiety levels and OCD symptoms in a short period of time so that the patient will see some immediate benefits of relief. (+)
3) BZ drugs have the strength that they can be used for short periods of time and they will produce hardly any real serious side effects unlike other types of drugs. Therefore side effects are kept to a minimum with BZ (in the short term) and this is a good point for the OCD patient (+)
Weakness of BZ drugs
4) However a problem of BZ drugs is that if they are used long term then several unwanted side effects can begin to appear, examples include drowsiness, depression and unpredictable interactions with alcohol. Patients have a high chance of being involved in accidents. Therefore BZ drugs should not be used as a long term treatment for OCD (-)
5) Ashton (1997) found that BZ have their weaknesses. Long term users of BZ became very dependent on the drug and a sudden withdrawal of the drug leads to a return of high levels of anxiety and OCD symptoms. There is also the problem of tolerance or drug escalation whereby patients need to take very large doses of the drug in order to reduce their OCD symptoms (if they take the drug for a long period of time). (-)
6) Stewart (2005) criticised long term use of BZ drugs as they cause impairment in speed and processing of verbal learning. These effects are temporary but are still negative. Stewart carried out a Meta analysis and found clear evidence that long term use of BZ leads to cognitive impairments. Cognitive ability seems to improve once the BZ drugs are withdrawn, but the cognitive ability is still below that of control patients who have never taken BZ. (-)
