OCD

• OCD


  an anxiety disorder characterized by unwanted repetitive thoughts (obsessions) and/or actions (compulsions)
• Behavioural characteristics of OCD

  - Compulsions (repetitive and reduce anxiety)

  - Avoidance
• Emotional characteristics of OCD

  - Anxiety and distress

  - Accompanying depression

  - Guilt and disgust
• Cognitive characteristics of OCD

  - Obsessive thoughts

  - Cognitive strategies to deal with obsessions

  - Insight into excessive anxiety
• Diathesis-stress model


  A diagnostic model that proposes that a disorder may develop when an underlying vulnerability is coupled with a precipitating event

  
• Candidate genes


  Genes that create a vulnerability for OCD, some of these genes help regulate serotonin.
• Polygenic


  Trait controlled by two or more genes
• Different types of OCD

  Aetiologically heterogenous - one group of genes may cause OCD in one person but different groups of genes may cause disorder in another person

  
  

  - also some evidence to suggest that different types of OCD may be result of particular genetic variations, such as hoarding disorder and religious obsession
• Strength of the genetic explanations

  Research support

  - Nestdadt (2010) found 68% of identical twins shared OCD as opposed to 31% of non-identical twins.
• Limitations of the genetic explanation


  Partial Explanation

  - OCD doesn't appear to be entirely genetic in origin and it seems that environmental risk factors can also trigger developing OCD.
• Role of serotonin


  Low levels of this neurotransmitter leads to abnormal transmission of mood relevant information and so mood and sometimes other mental processes are affected.
• Decision-making systems


  - OCD may be associated with abnormal functioning of the lateral of the frontal lobes of the brain.

  - There is also evidence to suggest an area called the left parahippocampal gyrus functions abnormally in OCD.
• Strengths of the neural explanation

  Research support

  - Antidepressants that work purely on serotonin are effective in reducing OCD symptoms and this suggests that serotonin may be involved in OCD.
• Limitations of the neural explanation

  No unique neural system

  - Many people with OCD experience clinical depression.

  - Having 2 disorders together is called co-morbidity.
• SSRIs


  Increase serotonin levels in CNS by inhibiting their presynaptic reuptake
• Combining SSRIs with other treatments

  SSRIs reduce the patients emotional symptoms which means that they can engage more effectively with CBT
• Tricyclics


  A class of antidepressant drugs that increase the level of norepinephrine and serotonin.
• SNRIs


  Serotonin and norepinephrine reuptake inhibitors
• Strengths of drug therapy

  Evidence for effectiveness

  - Soomro et al (2009) reviewed 17 studies that compared SSRIs to placebos in the treatment of OCD.

  - All 17 studies showed significantly better outcomes for SSRIs than for the placebo conditions.

  - HOWEVER, Skapinakis et al (2016) carried out a systematic review of outcome studies and concluded that both cognitive and behavioural therapies were more effective than SSRIs in the treatment of OCD.

  
  

  Cost-effective and non-disruptive

  - Cheap compared to psychological treatments because many thousands of tablets doses can be manufactured in the time it takes to conduct one session of psychological therapy.

  - If you wish you can simply take drugs until your symptoms decline.
• Limitations of drug therapy

  Serious side-effects

  - Indigestion, blurred vision and loss of sex drive.

  
  

  Biased evidence

  - Researchers are sponsored by drug companies and may selectively publish positive outcomes for the drugs their sponsors are selling.

  - There is a lack of independent studies of drug effectiveness and also research on psychological therapies may be biased.
• OCD


  an anxiety disorder characterized by unwanted repetitive thoughts (obsessions) and/or actions (compulsions)
• Behavioural characteristics of OCD

  - Compulsions (repetitive and reduce anxiety)

  - Avoidance
• Emotional characteristics of OCD

  - Anxiety and distress

  - Accompanying depression

  - Guilt and disgust
• Cognitive characteristics of OCD

  - Obsessive thoughts

  - Cognitive strategies to deal with obsessions

  - Insight into excessive anxiety
• Diathesis-stress model


  A diagnostic model that proposes that a disorder may develop when an underlying vulnerability is coupled with a precipitating event

  
• Candidate genes


  Genes that create a vulnerability for OCD, some of these genes help regulate serotonin.
• Polygenic


  Trait controlled by two or more genes
• Different types of OCD

  Aetiologically heterogenous - one group of genes may cause OCD in one person but different groups of genes may cause disorder in another person

  
  

  - also some evidence to suggest that different types of OCD may be result of particular genetic variations, such as hoarding disorder and religious obsession
• Strength of the genetic explanations

  Research support

  - Nestdadt (2010) found 68% of identical twins shared OCD as opposed to 31% of non-identical twins.
• Limitations of the genetic explanation


  Partial Explanation

  - OCD doesn't appear to be entirely genetic in origin and it seems that environmental risk factors can also trigger developing OCD.
• Role of serotonin


  Low levels of this neurotransmitter leads to abnormal transmission of mood relevant information and so mood and sometimes other mental processes are affected.
• Decision-making systems


  - OCD may be associated with abnormal functioning of the lateral of the frontal lobes of the brain.

  - There is also evidence to suggest an area called the left parahippocampal gyrus functions abnormally in OCD.
• Strengths of the neural explanation

  Research support

  - Antidepressants that work purely on serotonin are effective in reducing OCD symptoms and this suggests that serotonin may be involved in OCD.
• Limitations of the neural explanation

  No unique neural system

  - Many people with OCD experience clinical depression.

  - Having 2 disorders together is called co-morbidity.
• SSRIs


  Increase serotonin levels in CNS by inhibiting their presynaptic reuptake
• Combining SSRIs with other treatments

  SSRIs reduce the patients emotional symptoms which means that they can engage more effectively with CBT
• Tricyclics


  A class of antidepressant drugs that increase the level of norepinephrine and serotonin.
• SNRIs


  Serotonin and norepinephrine reuptake inhibitors
• Strengths of drug therapy

  Evidence for effectiveness

  - Soomro et al (2009) reviewed 17 studies that compared SSRIs to placebos in the treatment of OCD.

  - All 17 studies showed significantly better outcomes for SSRIs than for the placebo conditions.

  - HOWEVER, Skapinakis et al (2016) carried out a systematic review of outcome studies and concluded that both cognitive and behavioural therapies were more effective than SSRIs in the treatment of OCD.

  
  

  Cost-effective and non-disruptive

  - Cheap compared to psychological treatments because many thousands of tablets doses can be manufactured in the time it takes to conduct one session of psychological therapy.

  - If you wish you can simply take drugs until your symptoms decline.
• Limitations of drug therapy

  Serious side-effects

  - Indigestion, blurred vision and loss of sex drive.

  
  

  Biased evidence

  - Researchers are sponsored by drug companies and may selectively publish positive outcomes for the drugs their sponsors are selling.

  - There is a lack of independent studies of drug effectiveness and also research on psychological therapies may be biased.