Fichas
OCD
Fichas del conjunto (18)
- 1Emotional Characterisics- Both the obsessions and compulsions are a source of distress and anxiety
- Sufferers are aware of their excessive behaviour and this causes embarrassment and shame - 2Cognitive Characteristics- Obsessions are recurrent, intrusive thoughts or impulses that are perceived as forbidden
- Thoughts and impulses are not just excessive worries about everyday problems: they are seen as uncontrollable causing anxiety - 3Behavioural Characteristics- Compulsive behaviours are performed to relieve the anxiety created by the obsessions
- They are repetitive and unconcealed, or mental
- Patients are compelled to carry out these actions otherwise they believe something bad will happen - 4Biological Approach for Explaining OCD - GENETIC EXPLANATIONS -COMT gene:
- Regulates the production of dopamine that has been implicated in OCD
- An allele of the COMT gene has been found more common in patients with OCD
- This allele produces lower activity of COMT and increased the levels of dopamine
- Tükel et al., 2013 - 5Biological Approach for Explaining OCD - GENETIC EXPLANATIONS -SERT gene:
- (5-HTT) affects the transport of serotonin, lowering the levels of the neurotransmitter
- A mutation of this gene was found in 2 unrelated families where 6/7 family members had OCD
- Ozaki et al., 2003 - 6Biological Approach for Explaining OCD - GENETIC EXPLANATIONS -Diathesis-stress:
- The link between 1 gene and a complex disorder such as OCD is unlikely
- Eg: SERT is also involved in PTSD
- Each gene may create a vulnerability (diathesis). Other factors (stressors) affect what condition develops, and if one develops at all - 7Biological Approach for Explaining OCD - NEURAL EXPLANATIONS -Abnormal levels of neurotransmitters
- Dopamine levels are thought to be abnormally high in those with OCD (based on animal studies - high doses of dopamine = compulsive behaviour
- Low levels of serotonin = antidepressants increase the levels of serotonin activity reduce symptoms - 8Biological Approach for Explaining OCD - NEURAL EXPLANATIONS -Abnormal brain circuits
- Several areas in the frontal lobe are thought to be abnormal in those with OCD
- Caudate nucleus suppresses signals from the OFC. - OFC sends signals to the thalamus about things that are worrying
- CN is damaged = fails to suppress minor worries = worry circuit (PET Scans) - 9EvaluationResearch support for genes and OFC
> Menzies et al 2007 used MRI images on OCD patients and unaffected relatives and a group of healthy people
> OCD patients and families had less grey matter in key areas (OFC)
> Can be used to detect OCD risks - 10EvaluationAlternative Explanations
> Two-process model can be applied to OCD.
> Exposure and response prevention treatment - similar to SD
> Confronted with anxiety creating stimulus and prevented from carrying out compulsions
> Albucher (1998) - 60-90% improvement - 11EvaluationFamily and Twin studies
> Genetic basis of OCD comes from first-degree relatives and twins
> Meta-analysis of 14 twin studies - MZ were 2x likely to develop OCD if their twin had it: Billett et al (1998)
> Concordance rates are never 100% = environmental factors - 12Biological Approach for Treating OCD Drug TherapyAnti-depressants - SSRIs
- Anti-depressants are used to reduce the anxiety associated with OCD
- Selective serotonin reuptake inhibitors
- Blocks reabsorption - 13Biological Approach for Treating OCD Drug TherapyAnti-depressants - Tricyclics
- Blocks the transporter mechanism that reabsorbs both serotonin and noradrenaline leaving them in the synaptic cleft prolonging their activity
- Targets more than one neurotransmitter
- More side effects - 14Biological Approach for Treating OCD Drug TherapyAnti-anxiety drugs
- Benzodiazepines (BZs) used to reduce anxiety
- Slows the activity of the CNS by enhancing the activity of GABA
- Opens a channel that increases the flow of chloride ions into the neuron - makes it harder for the neuron to be stimulated - 15Biological Approach for Treating OCD Drug TherapyOther drugs
- D-Cycloserine has an effect on reducing anxiety and may be effective in treating OCD
- An antibiotic used in treatments of TB
- Enhances the transmission of GABA (Kushner et al 2007) - 16EvaluationSide effects
> SSRIs = nausea, headaches and insomnia (Soomro et al, 2008) patients may refuse
> Tricyclics = Hallucinations and irregular heartbeat - used when SSRIs don't work
> BZs = aggressiveness and long-term impairment of memory and addiction (max 4 weeks) - 17EvaluationPublication Bias
> Turner et al 2008 claim that benefits of antidepressants were exaggerated
> Studies that did not have positive outcomes were still published in a way that conveyed a positive outcome
> Selective publication can lead to making inappropriate treatment decisions - 18EvaluationDrug therapies are preferred to other treatments
> Requires little effort from patients and little input of time, unlike CBT
> Cheaper as they require little monitoring