OCD Flashcards
Behavioural Characteristics
Compulsions/ repetitive behaviour
Avoidance
Emotional characteristics
High anxiety/low mood
Disgust/ self-loathing
Cognitive characteristics
Obsessions/obsessive thoughts/irrational beliefs
Insight into irrationality of thoughts and behaviour/awareness that behaviour is irrational/insight into excessive anxiety
Hyper vigilance/selective attention
Compulsions
Repetitive actions that can seriously hinder the person’s ability to perform everyday tasks.
Reduce anxiety created by obsessions
Feels like they must perform these actions or something dreadful might happen
Avoidance
Try to reduce anxiety by avoiding situations that might trigger it.
High anxiety/ low mood
The obsessions and compulsions are a source of considerable anxiety and distress. They’re aware that these are excessive- causes shame and embarrassment. Might be aware that can’t control compulsive behaviour- strong feelings of distress.
Obsessions
Persistent, intrusive, irrational thoughts perceived as inappropriate or forbidden. May be frightening or embarrassing.
Not worries about everyday problems, uncontrollable and cause anxiety.
Catastrophic thinking - think something terrible will happen if they don’t follow compulsions.
Awareness behaviour is irrational
Most sufferers know their obsessions and compulsions are inappropriate or irrational, but can’t consciously control or stop them.
Hyper vigilance
Increased awareness of source of obsession in new situations.
Polygenic
one single gene is not responsible for the disorder
Candidate genes
Genes that may be responsible for a behaviour
GABA
Neurotransmitter that is released when people take Benzodiazepine
SERT
Gene that affects transportation of Serotonin
COMT
Gene that regulates production of the neurotransmitter dopamine
Serotonin
Low levels of this neurotransmitter will result in a low mood
Caudate nucleus
Area of the brain that serotonin plays a key role in operating
SSRI
Drug that prevents serotonin being reabsorbed by the pre-synaptic neuron
Genetic explanation
Some researchers suggest that OCd is an inherited condition
Dopamine
Higher levels of dopamine have been found to be more common in OCD patients
Genetic explanations
COMT gene variation that leads to higher dopamine, more common in OCD patients .
SERT gene where it causes lower levels of serotonin, have been linked to OCD.
Strengths of genetics explanations
Research support - found concordance rates for OCD between monozygotic twins was significantly higher than between dizygotic twins.
Animal studies have found there is genetic basis for repetitive ritualistic behaviour in animals. E.g. common gene in mice who display ritualistic behaviour.
Weakness of genetic explanations
Around half of all cases of OCD tend to follow trauma, undermining genetic explanation. Also cannot account for cases of OCD in families where there is no previous history of OCD.
Neural explanations
Dopamine and serotonin are neurotransmitters that affect mood. Abnormal levels of these neurotransmitters are associated with abnormal transmission of mood-related information.
Dopamine - neural explanation
OCD sufferers have high levels of dopamine, which have been linked to over hyperactivity in the basal ganglia area in the brain. This causes repetitive motor functions e.g. compulsions.
Serotonin - neural explanation
Serotonin plays a key role in operating the caudate nucleus in the basal ganglia of the brain, and it seems that low levels of serotonin cause the caudate nucleus to malfunction. In particular low levels of serotonin result in obsessions.
Strength of neural explanations
Anti depressant drugs increase serotonin levels in OCD patients, and this has lead to a reduction in OCD symptoms. Therefore there is good evidence to suggest that low levels of serotonin could be a cause for OCD.
Weakness of neural explanation
Neurotransmitters such as serotonin and dopamine might not necessarily cause OCD. Instead they might be symptoms of OCD.
Drug therapy for OCD
The biological approach uses drug therapy to correct the imbalance of neurochemicals to reduce symptoms.
SSRI full form
Selective serotonin re-uptake inhibitors
Serotonin between neurons
Serotonin is released by presynaptic neurons and travels across synaptic cleft. Chemically conveys signal from presynaptic neuron to postsynaptic neurones and is then reabsorbed by presynaptic neuron where it is broken down and refused.
SSRI Treatment
Anti-depressants called SSRIs, e.g. Prozac, fluoxetine etc.
SSRIs prevent the reabsorption and breakdown of serotonin and so increase the level of serotonin in the synapse where it continues to stimulate the postsynaptic neurones and is. The effect of this should be to reduce anxiety.
Typically takes 3-4 months of daily use for impact on symptoms. Typical dosage may be increased if not benefitting patient as appropriate.
Strengths of SSRIs
Soomro 2009 reviewed 17 studies that compared SSRIs to placebo drugs for treating OCD, all showed SSRIs were more effective, especially when combined with CBT
70% of patients have seen a decline in OCD symptoms when taking SSRIs. Remaining 30% tend to opt for psychological therapies or combination of both.
Weakness of SSRIs
Have severe side effects which might mean that OCD patient might stop taking the medication. Are temporary but include indigestion, blurred vision and loss of sex drive.
Benzodiazepines
Anti anxiety drugs such as BZ are commonly used to treat OCD e.g. valium and diazepam. They slow down activity of the CNS by enhancing activity of the neurotransmitter GABA, which has an inhibitory effect on neurons.
What does GABA do
Reacts with special sites called GABA receptors on the outside of neurone. This opens a channel that increases the flow of chloride ions into the neuron. These make it harder for the neuron to be stimulated by
Strength of benzodiazepines
Can begin to reduce anxiety levels and OCD symptoms in a short period of time, especially compared to other treatments like CBT, so that the patient experiences immediate relief.
Benzodiazepines weakness
If BZ drugs are used long term then several unwanted side effects can begin e.g. drowsiness, depression and unpredictable interactions with alcohol. Ashton found that long-term users became dependent and a sudden withdrawal of drug lead to a return of high levels of anxiety and OCD symptoms.
Also the problem of tolerance where patients need to take larger doses of the drug in order to reduce their OCD symptoms because body gets used to the drug.
