(5)Psychopathology - BIOLOGICAL EXPLANATION/TREATMENT OCD Flashcards
Which 3 drugs are used for treating OCD?
SSRIS (anti-depressants) , benzodiazepines (anti anxiety) and D-cycloserine
SSRIS
antidepressants, most commonly used for OCD treatment, aim to increase levels of serotonin via synaptic transmission:
SSRIS block/inhibit the reputable of serotonin back into the pre synaptic gap- makes more serotonin available in the synapse- binds to receptors in post synaptic neuron
This reduces symptoms of anxiety, regulates mood= alleviates symptoms of OCD
Benzodiazepines
Anti-anxiety drug- shuts down activity in the central nervous system by enhancing activity of GABA- GABA reduces brain activity which promotes relaxation + reduces anxiety = alleviates symptoms of OCD
D-Cycloserine
Anti-biotic drug, used to treat tuberculosis- enhances transmission of GABA. This reduces the anxiety and therefore treats OCD
(+) AO3- Drug treatments- LESS TIME+EFFORT THAN OTHER TREATMENTS FOR OCD
Only requires taking medication daily vs treatments like CBT require patient engaging in lots of activities, daily therapy sessions usually for over a year.
People therefore will continue to take these treatments due to the little effort they require, which reduces symptoms of OCD =effective treatment
Also cheaper than CBT- saves NHS money = effective
(-)AO3-drug treatments- SIDE EFFECTS
SSRIs= irritability, increased suicide risk, tiredness
Bzs= addiction to the drug
This may lead to people stopping taking them due to the negative side effects- therefore not an effective treatment for OCD
(-) AO3-drug treatments- TREATS SYMPTOMS, NOT CAUSE-NOT A CURE
Reduces the depressive symptoms of OCD- only provide temporary relief from the obsessive thoughts + compulsive behaviours- don’t directly eliminate the obsessive thoughts themselves which may be why relapse rate is so high
-drugs not effective at treating core symptoms of OCD
(+)AO3-drug treatments-RESEARCH TO SUPPORT-SOOMRO ET AL
Soomro- reviewed 17 studies comparing SSRIS to placebo drug in people with OCD- concluded all 17 showed significantly better recovery rates for SSRIS for treating OCD.
strength- shows drug treatments are effective
What are the two biological explanations of OCD?
The Genetic and neural explanation
Genetic explanation of OCD- hereditary
Suggest the disorder is genetically inherited and runs in families- Groothest- reviewed 70 yrs of twin studies with OCD- 10,000 twins reviewed. Found MZ twins had a higher concordance rate of both of them having the disorder (45-65%) vs DZ (0-25%)
—> suggest a high genetic influence to OCD
Genetic explanation of OCD- genes linked to OCD
COMT and SERT gene linked to OCD- (candidate genes)
SERT gene effects transport of serotonin- variation of SERT leads to lower levels of serotonin in brain= linked with OCD
COMT gene regulates dopamine levels- mutation= lower levels of activity, higher levels of dopamine= linked with OCD
Tuckel et al- variation of COMT gene more common in patients w/ OCD vs people without the disorder
Ozaki et al- mutation of SERT gene in 2 unrelated families- 6/7 members had OCD
Genetic explanation of OCD- poly genetic and aetiologically heterogenous
-Also suggested OCD may be polygenetic- meaning it’s influenced by a genetic variation of 2/ more genes- Taylor et al- found 280 different candidate genes associated with OCD= OCD polygenetic
-May also be aetiologically heterogenous- means different combinations of these genes cause OCD in people- 1 sufferer may have different combination of genes influencing their OCD compared to another sufferers.
KEY WORDS TO REMEMBER FOR GENETIC EXPLANATION FOR OCD
-Hereditary (higher concordance rate In MZ twins, higher risk in 1st degree relatives)
-Candidate genes (SERT + COMT)
-Polygenetic
-Aetiologically heterogeneous
(+)AO3- genetic explanation-RESEARCH TO SUPPORT
Nestadt—> 5X greater risk in developing OCD in people with 1st degree relatives with OCD (vs ppl without)
Groothest—> 70yrs of twin studies with OCD, 10,000 twins- higher concordance rate for both MZ twins having OCD (45-65%) vs both DZ twins having OCD (0-25%)
—> SUGGEST OCD INHERITED/RUN IN FAMILIES.
GENETIC COMPONENT TO THE DISORDER
(-)AO3 Genetic explanation- WEAKNESS OF USING TWIN STUDIES/FAMILY STUDIES
-difficult to separate genes from environment- the high concordance rate could be due to an environmental factor as twins and families usually share same environments.
-never 100% concordance rate-must be other factors influencing OCD other than genetics
-Groothest-much smaller evidence for a genetic link for OCD that developed in adulthood- weaker evidence for OCD in adults
(+)AO3-genetic explanation-REDUCTIONIST
-only considers genes-ignores environmental factors-studies show that over 1/2 of people with OCD diagnosis had suffered traumatic event in their past-more severe trauma=worse OCD symptoms.
-diathesis-stress model-genetic predisposition to OCD, triggered by environmental stimuli- the fact twins don’t have 100% concordance rate for OCD further suggests other factors must be involved
—>oversimplistic, purely nature, doesn’t consider other factors
(Ao1)Neural explanations-neurotransmitters
abnormal levels of neurotransmitters- dopamine levels abnormally high due to COMT gene variant- seratonin levels abnormally low due to SERT gene variant.
—>IMPLICATED IN OCD
(Ao1)Neural explanations-abnormal brain circuits/abnormality in logical thinking.
-some cases of OCD associated with impaired decision making-this is due to variant in FRONTAL CORTEX
-OCD is also linked inability to process unpleasant emotions- due to parahippocampal gyrus functioning abnormally(usually processes these unpleasant emotions)
Ao1Neural explanations-abnormality in ‘worry circuit’
-person worries too much=OCD
due to: THALAMUS picks up worry signals from ORBITAL FRONTAL CORTEX and directs them around the body. CAUDATE NUCLEUS picks up worry signals and suppresses them. UNDER-ACTIVE CAUDATE NUCLEUS= worry signals not suppressed—> OCD
-Hyperactivity of basal ganglia also associated with OCD
KEY WORDS TO REMEMBER FOR NEURAL EXPLANATION OF OCD
-abnormal levels of neurotransmitters(dopamine,seratonin)
-abnormal brain circuits(frontal cortex variant)
-abnormality in logical thinking(parahippocampal gyrus abnormality)
-abnormality in worry circuits( OFC—>THALAMUS—>UNDER-ACTIVE CAUDATE NUCLEUS= WORRY SIGNALS NOT SUPPRESSED)
-hyperactivity of basal ganglia
(+) AO3- Neural explanation- PRACTICAL APPLICATIONS
-Successful treatment produced-SSRI anti depressants, Benzodiazepine anti anxiety drugs, D-Cycloserine- used to successfully reduce symptoms of OCD
—>treatment based of assumptions of neural approach and is successful= suggests approach has validity
(-)AO3-neural explanation- OVERSIMPLISTIC
Ignores other causes of OCD such as learning/trauma
-traumatic event may have triggered OCD (over 1/2 ppl with OCD suffered a traumatic event in their life)
-OCD may also be learnt like phobias via classical and operant conditioning—>initiation- NS like dirt is associated with anxiety. maintained via operant-person may repeatedly wash hands to reduce the anxiety (negative reinforcement). This leads to obsessions forming with compulsions being reinforced because of the relief it provides from the obsessions.
—> not a complete explanation
