OCD Flashcards
What are the behavioural characteristics of OCD
theres 2
- Compulsions - repetitive actions to reduce anxiety stemming from obsessions
- Avoidance - attempt to reduce anxiety by avoiding situations that may trigger it
What are the emotional characteristics of OCD
theres 2
- Anxiety - stems from awareness of behaviour being excessive and know they can’t control themselves, feeling shame
- Disgust - either at self or at external sources
What are the cognitive characteristics of OCD
theres 3
- Obsessions - recurrent intrusive irrational thoughts which cause anxiety
- Awareness of Irrationality - sufferers understand their behaviour and thoughts are inappropriate but they still can’t control it
- Catastrophic Thinking - worried that if they do not carry out compulsion, something bad will happen (irrational)
What’re the two biological explanations of OCD & the assumptions
assumptions of the biological explanations
- Genetic explanation
- Neural explanation
- caused by genetic and biochemical factors
What is the genetic explanation of OCD
- OCD is classed as polygenic (many candidate genes responsible for causing)
- COMT gene - regulates dopamine production. High dopamine associated w/ OCD.
- Variation of COMT gene that produces higher levels of dopamine is common with OCD patients
- SERT gene - affects transportation of serotonin. Causing lower levels. Low serotonin is linked to OCD
What is the neural explanation of OCD
- abnormal levels of neurotransmitters are associated with OCD (dopamine+serotonin)
- high dopamine levels are linked to hyperactivity in the basal ganglia area in the brain (causes compulsions)
- low levels of serotonin in the caudate nucleus in the basal ganglia cause the caudate nucleus to malfunction (causes obsessions)
Research Support for genetic explanation
(+) smth about relatives n OCD idk
Nestadt(2000)
found that people with a first degree relative with OCD were five times more likely to have OCD
Research Support for genetic explanation
(+) Meta-analysis of 14 twin studies
Billett(1998)
OCD is 2x more likely to be concordant in identical monozygotic twins rather than dizygotic (non identical)
found from a meta-analysis of 14 twin studies
(-) smth about concordance rates
weakness for genetic explanation
- Concordance rate in identical twins is not 100%
Thus fails to account psychological and environmental factors
(-) Biological approach contradicts with behavioural approach.
Two process model suggests that OCD is learnt via classical conditioning and reinforced through operant conditioning
OCD is often treated with behavioural therapies such as exposure (similar to SD)
Strength for neural explanation
(+) Antidepressants work
Antidepressants increase serotonin levels
Has shown reduction in OCD symptoms
Strength for neural explanation
(+) Risperidone
Ciccerone(2000)
found giving patients low doses of drug Risperidone to lower dopamine caused symptoms of OCD to alleviate
Weakness of neural explanation
(-) Cause n effect
Neurotransmitters may not necessarily cause OCD but rather just a symptom
(low serotonin, high dopamine)
Weakness for neural explanation
(-) Co-morbidity
OCD is co morbid with depression
It is unclear if low serotonin causes OCD or depression or both
Link is unclear
What is the biological treatment for OCD
- Uses medication to increase/decrease neurotransmitter levels
-general purpose to decrease heart rate, anxiety, low arousal, blood pressure
What are selective serotonin re-uptake inhibitors (SSRIs)
- Serotonin release by presynaptic neurons.
-Travel across synaptic cleft. - Chemically convey signal from presynpatic neuron to postsynaptic neuron
-reabsorbed (re-uptake) by presynaptic neuron
-broken down and reused
SSRIs prevent reabsorption & breakdown of serotonin.
-increase levels in synapse
-continues to stimulate postsynaptic neuron
-reduces anxiety
What are benzodiazepines (BZs)
- Anti-anxiety drugs (Valium, diazepam)
Slow activity of CNS by enhancing neurotransmitter GABA (has inhibitory effects on neurons)
- GABA reacts with GABA receptors outside neurons
-GABA locks into these receptors
-opens channel to increase chloride ion flow into neuron
Chloride ions make it harder for neuron to be stimulated by other neurotransmitters (slows down neural activity, makes person relaxed)
(+) Research support for SSRIs
Soomro(2009)
reviewed 17 studies comparing SSRIs with placebos
-all 17 studies showed SSRIs were more effective especially when combined with CBT
(+) SSRIs work
70% of patients that take SSRIs see a decline in symptoms
30% opt for psychological therapies or a combo of both
SSRIs weakness
(-) Side effects
Severe side effects meaning they may stop taking it making it ineffective
-Symptoms include indigestion, blurred vision, loss of sex drive
(+) Benzodiazepines work
reduce anxiety levels and OCD symptoms quickly, compared to CBT where patient doesn’t experience immediate relief
(-) Side effects of benzodiazepines
if used long-term then side effects appear
-side effects include drowsiness, depression, unpredictable interactions with alcohol
(-) Becoming dependent on benzodiazepines
Ashton(1997)
found long-term users to become dependent and experience high levels of anxiety + symptoms with withdrawal.
-patients need progressively larger doses to reduce symptoms because tolerance (body gets used to drug)
