Session Thirteen (OCD) Flashcards
How are Obsessions defined according to DSM/ICD?
Recurrent and persistent intrusive thoughts, impulses, urges or images that are:
- unwanted
- stress or anxiety inducing
- difficult to suppress or ignore
How are Compulsions defined according to DSM/ICD?
Repetitive behaviours or mental acts that the person feels driven to perform in response to an obsession, according to rigid rules, or to achieve a sense of completeness
How do ICD and DSM define OCD?
- Compulsions in the presence of Obsessions.
- Must be time consuming (1+ hour/day)
- Must cause significant distress or impairment to family, social, educational, occupational, functioning.
- Not attributable to another mental disorder or drug
- Level of insight into their condition (DSM definition requires the patient to on some level understand their compulsions to be excessive and unreasonable)
Who gets OCD?
- 1.2% prevalence in population
- Slightly more common in women 1.4 : 1
- Consistent across all cultures
How have people tried to subcategorise OCD?
Mataix-Cox breaks it down into the following groupings:
- Symmetry and ordering obsessed
- Contamination and cleaning obsession
- Checking
- Hoarding
Bragdon and Coles take a more broad view and just subdivide it into:
- Harm avoidance
- ‘Not just right’ experiences
What is the life impact of OCD?
- High rates of comorbidity with depression and GAD
- Reduces odds of being married or employed, leading to significantly reduced QoL (Torres et al, 2006)
- WHO considers it one of the top 10 most disabling conditions in the world
Describe the course of OCD?
- Starts before age of 30
- Triggered or exacerbated by transitions
- Impairment in QoL persists over lifespan
- Often long delay in seeking healthcare (upwards of 10 years)
What causes OCD?
Nobody knows!
- Likely a biopsychosocial element
- Combined with a stress/vulnerability element
Give some evidence for a genetic cause of OCD?
Beam et al, 2017:
- Raised familial prevalence of OCD and other problems (D + A)
- No OCD-specific genetic factors have been identified
Taylor et at, 2013
- Found consistent implication of genes related to serotonin regulation in OCD
- However, mechanisms unclear
- Unlikely to be specific to OCD
Give some evidence for a neuropsychological aspect to OCD?
Cougle et al, 2007:
- Found no differences in memory between OCD and HCPs
- However did find a difference in confidence in their memory
Give some evidence for a neuroanatomical/ functional aspect of OCD?
No consistent findings.
However, Swedo et al, 1992:
- Orbitofrontal-subcortical hypothesis
- Improvements in OCD correlated with reduction in activity of orbitofrontal cortex.
Give some evidence for a neuropharmacological aspect to OCD?
Rapoport et al, 1989:
- Serotonin hypothesis
- Based on success of tricyclic or SSRI treatments in OCD
Separate research has suggested a role for dopamine, due to some evidence for efficacy of augmentation therapy using anti-psychotics.
However Veale et al (2014) dispute this, claiming that only small or modest effect sizes were shown for Risperidone augmentation, and none at all for other anti-psychotics such as Olanzapine (on meta-analysis).
What are the major limitations of the biological theories explaining OCD?
Can’t explain:
- The heterogeneity or specificity of symptoms (i.e. why someone might rather than wash)
- Effectiveness of certain therapies, for example in vivo exposure response therapy has shown to be beneficial (if OCD is neurochemical why would these therapies have an effect?)
Briefly outline the psychoanalytical theory of OCD?
- Freud; ID vs Superego
- Adler; Reaction to over control in early environment
- Others have described it as a minor psychosis
- therapies are based around lifting repression and airing unresolved conflict in the open.
Issues:
- Doesn’t explain relief patients will eventually experience when they are prevented from performing their rituals
- Doesn’t explain the fact that intrusive thoughts occur in 90% of normal people (Rachman et al, 1978)
Briefly outline the behavioural theory of OCD?
Classical Conditioning –> Obsessions
Operant Conditioning –> Compulsions
Rachman, 1971:
- Obsessional thoughts have become associated with anxiety through class conditioning
- Compulsions are reinforced through operant conditioning
Has solid basis in interventions, can give Exposure and Response Prevention therapy
What is the key study supporting Rachman’s behavioural model, and outline it?
The Spontaneous Decay study (Rachman et al, 1971):
- Provoked the urge to check in 12 obsessional checkers
- Half allowed to check immediately and half asked to wait
- Immediate checking lead to a reduction in anxiety, but similar reductions were observed in the waiting group after about an hour
- Shows that anxiety around OCD will eventually decay spontaneously
- Anxiety and O/Cs are associated with each other but not one and the same, can be disassociated (as per Class Con explanations)