PSYCHOPATHOLGY: OCD Flashcards
Definition of OCD
A conditioned characterised by obsession and compulsion
Behavioural characteristics: OCD
— compulsions (performing repetitive actions)—
-typically people suffering from OCD feel compelled to repeat a behaviour in an attempt to manage the anxiety produced by their obsession
>eg. Hand washing
— Avoidance—
- can help reduce anxiety by keeping away from situations that trigger it
> eg. Someone who is scared of germs might refuse to do the bins
Behavioural characteristics: OCD
— compulsions (performing repetitive actions)—
-typically people suffering from OCD feel compelled to repeat a behaviour in an attempt to manage the anxiety produced by their obsession
>eg. Hand washing
— Avoidance—
- can help reduce anxiety by keeping away from situations that trigger it
> eg. Someone who is scared of germs might refuse to do the bins
Emotional characteristics of OCD
Anxiety and distress
- accompanies both obsessions and compulsions
- obsessive thoughts are frightening
> and the anxiety that goes with these can be overwhelming - the urged so repeated behaviour (compulsions) also create anxiety
Cognitive characteristics of OCD
—Obsessions—
Obsessive thoughts which are usually irrational and very repetitive
Eg. Certainty that the door is unlocked so a murder will enter
—hyper-vigilance/selective attention—
Increased awareness of source of obsession
—catastrophic thinking—
-occurs when people have a hard time weighing the likelihood of certain outcomes
> believes that terrible or catastrophic outcomes are extremely likely
Biological explanations: GENETIC EXPLANATION
> what is genetic explanation<
The idea that genes (we inherit from out parents) determines how VULNERABLE we are to OCD
Someone people are therefor predisposed to develop the disorder because of inherited familial influence, making them vunderable
Biological explanations: GENETIC EXPLANATION
> what are candidate genes?<
=genes which create VULNERABILITY for OCD, some genes are involved in regulating neurotransmitters that affect mood
COMPT AND SERT
Biological explanations: GENETIC EXPLANATION
> COMPT<
Regulated dopamine
One variation of this gene results in HIGHER levels of dopamine
(More common in patients with OCD)
Biological explanations: GENETIC EXPLANATION
> SERT<
This gene regulated levels of SEROTONIN
-affects the transport of serotonin causing LOWER levels of serotonin (which is also associated with OCD)
Biological explanations: GENETIC EXPLANATION
> Polygenic<
Means that OCD is not caused by a singly gene but several genes involved
-Taylor (2013) has analysed findings of previous studies and found evidence but up to 230 different genes may be involved in OCD: commonly associated with dopamine and serotonin
- one group of genes may cause OCD in one person but another group of genes may cause it in another person
Biological explanations: GENETIC EXPLANATION
> diathesis -stress model<
- according to the diathese stress model,
Genes leave some people more vulnerable to OCD but some environmental distress is needed to trigger the condition
Therefore there are some people who have the COMPT and SERT genes, but would suffer no ill effects
Biological explanations: GENETIC EXPLANATION
> positive evaluations<
Good supporting evidence
Nestadt et al (2010) reviewed previous twin studies and found that 68% of identical twins shared OCD opposed to 31% of non identical twins
—this strongly supports the genetic influence on OCD
— COUNTER ARGUMENT—
Twin studies are flawed
- they overlook the influence of shared environment
• Lewis (1936) observed that of his OCD patients 37% had parents with OCD and 21% had siblings with OCD. - This suggests that OCD runs in families, although what is probably passed on from one generation to the next is genetic vulnerability not the certainty of OCD.
Biological explanations: GENETIC EXPLANATION
> negative evaluations<
(-) too many candidate genes
• although twin studies strongly suggest that OCD is largely under genetic control, psychologists have been much less successful at pinning down all the genes involved.
- One reasons for this is because it appears that several genes are involved and that each genetic variation only increases the risk of OCD by a fraction.
- The consequence is that a genetic explanation is unlikely to ever be very useful because it provides little predictive value.
(-) environmental risk factors
It seems that environmental factors can also trigger or increase the risk of developing OCD (the diathesis-stress model).
- For example, Cromer et al (2007) found that over half the OCD patients in their sample had a traumatic event in their past, and that OCD was more severe in those with more than one trauma.
> This suggests that OCD cannot be entirely genetic in origin, at least not in all cases. It may be more productive to focus on the environmental causes because we are more able to do something about these.
Biological explanations: NEURAL EXPLANATION
> basic explanation<
• The genes associated with OCD are likely to affect the levels of key neurotransmitters + structures in the brain
Biological explanations: NEURAL EXPLANATION
> Abnormal Neurotransmitters (biochemical explanation)<
Mark scheme: low levels of serotonin associated with anxiety; high levels of dopamine linked to compulsive behavior/ stereotypical movements
If a person has low levels of serotonin
>then normal transmission of mood-relevant information does not take place.
> Low levels of serotonin are associated with OCD.
This conclusion in based on the fact that antidepressant drugs that increase serotonin activity have been found to reduce symptoms of OCD (Pigott et al, 1990).
Dopamine levels are thought to be abnormally high in people with OCD. This is based on animal studies – high doses of drugs that enhance dopamine levels induce stereotyped movements resembling the compulsive behaviour found in OCD patients (Szechtman et al, 1998).
> the rats with increased dopamine = increased times they cleaned them selves
Biological explanations: NEURAL EXPLANATION
> Abnormal Brain Structures (physiological explanation)<
Another brain region associated with OCD is the orbitofrontal cortex,
> a region which converts sensory information into thoughts and actions.
> PET scans have found higher activity in the orbitofrontal cortex in patients with OCD.
>One suggestion is that the heightened activity in the orbitofrontal cortex increases the conversion of sensory information to actions (behaviours) which results in compulsions.
> The increased activity also prevents patients from stopping their behaviours.
Some cases of OCD seem to be associated with impaired decision making. This in turn may be associated with abnormal functioning frontal lobes
Hypersensitivity of the basal ganglia may result in repetitive movemments/ motor functions
There is also evidence to suggest that an area called the left parahippocampal gyrus, associated with processing unpleasant emotions functions abnormally in OCD
Biological explanations: NEURAL EXPLANATION
> brain structures<
FRONTAL LOBES = poor decision making
Basal Ganglia= repetitive movement
Parahippocampus Gyrus= Poor processing of unpleasant emotions
Orbitofrontal cortex = compulsions
Biological explanations: NEURAL EXPLANATION
COMPT = increased dopamine = Compulsions
SERT = decreased serotonin = anxiety
Biological explanations: NEURAL EXPLANATION
> positive evaluations<
1) (+) supporting evidence for neurotransmitters
some antidepressants work purely on the serotonin system, increasing levels of the neurotransmitter. Such drugs are effective in reducing OCD symptoms and this suggests that the serotonin system is involved in OCD.
• suggests that the biological processes that cause the symptoms in those conditions may also be responsible for OCD.
BUT… SSRI’s are only effective for about 50% of sufferers (find recent research).
2) (+) supportive evidence for physiological differences
• some support for claims, eg Rauch et al 1994, PET scans show over activity in basal ganglia, co-morbidity with Tourette’s which is also linked to basal ganglia (Rapoport 1990).
Biological explanations: NEURAL EXPLANATION
> negative evaluations<
(-) It is not clear exactly what neural mechanisms are involved = not causal = other factors? = correlational
• Studies of decision making have shown that neural systems are the same systems that function abnormally in OCD (Cavedini et al, 2002). > However, research has also identified other brain systems that may be involved but no system has been found that always plays a role in OCD. • Thus we should not assume that neural mechanisms cause OCD = There is evidence to suggest that various neurotransmitters and structures of the brain do not function normally in patients with OCD. >However, this is not the same as saying that this abnormal functioning CAUSES the OCD. These biological abnormalities could be a result of OCD rather than its cause, meaning there could be multiple other factors involved.
(-) Alternative explanations
• The biological approach faces strong competition from psychological explanations. > The two-process model can be applied to OCD. > Initial learning occurs when a neutral stimulus (e.g. dirt) is associated with anxiety. > This association is maintained by negative reinforcement. > An obsession is formed and then a link is learned with compulsive behaviour (e.g. hand-washing) which appears to reduce the anxiety.
• Such explanations are supported by the success of a treatment for OCD called exposure and response prevention which is fairly similar to SD.
>Patients have to experience their feared stimulus and at the same time are prevented from performing their compulsion.
> Studies have reported high success rates, for example Albucher et al (1998) reported that between 60-90% of adults with OCD have improved considerably.
> This suggests that OCD may have psychological causes as well as, or instead of, biological causes.
BIOLOGICAL TREATMENTS: SSRI
Selective serotonin, re-uptake inhibitors
- it aims to correct the imbalance of serotonin
- it works by inhibiting the re absorption of serotonin and leaves it in the brain for prolonged periods and allows serotonin to continue to stimulate the post synaptic neurone.
It normally takes 3-4 months of daily use for these treatments to start to work
Biological Treatments: alternatives
• SNRIs – more recent drugs which also increase levels of serotonin and nor-adrenaline and are tolerated by those for whom SSRIs are not effective.
• Tricyclics – These block the transporter mechanism that re-absorbs both serotonin and noradrenaline, again prolonging their activity. It is an older antidepressant and has more severe side effects than SSRIs, so is usually only used on those that other drug therapies have not worked. Advantage: targets more than 1 neurotransmitters. Disadvantage: greater side effects (thus it’s used as a second-line treatment)
Anti-anxiety drugs – such as benzodiazepines (which include trade names like Valium and Diazepam) – enhance the activity of GABA. GABA tells neurons in the brain to ‘slow down’ and ‘stop firing’ and around 40% of the neurons in the brain respond to GABA. This means that BZs have a general quietening influence on the brain and consequently reduce anxiety, which is experienced as a result of the obsessive thoughts.
POSITIVE EVALUATIONS OF biological treatments
• + THERE IS SUPPORTIVE EVIDENCE FOR THE EFFECTIVENESS OF BIOLOGICAL TREATMENTS FOR OCD.
• Soomro et al. (2008) conducted a review of the research examining the effectiveness of SSRIs and found that SSRIs were more effective than placebos in the treatment of OCD, in 17 different trials. This supports the use of biological treatments, especially SSRIs, for OCD.
• + BIOLOGICAL TREATMENTS ARE COST EFFECTIVE, NON-DISRUPTIVE, AND DONT REQUIRE MOTIVATION FROM PATIENTS.
• Another strength of biological treatments is their cost. Biological treatments, including anti-depressants and anti-anxiety drugs, are relatively cost effective in comparison to psychological treatments, like cognitive behavioural therapy (CBT). Consequently, many doctors prefer the use of drugs over psychological treatments, as they are a cost effective solution for treating OCD (and depression), which is beneficial for health service providers in comparison with alternative treatments. In addition, psychological treatments like CBT require a patient to be motivated. Drugs however are non-disruptive and can simply be taken until the symptoms subside. As a result, drugs are likely to be more successful for patients who lack motivation to complete intense psychological treatments.
Negative evaluation for Biological treatments
- BIOLOGICAL TREATMENTS FOR OCD MAY BE ADDICTIVE AND COME WITH LOTS OF SIDE EFFECTS WHICH LEADS PEOPLE TO STOP TREATMENT.
- However, one weakness of drug treatments for OCD is the possible side effects of drugs like SSRIs and BZs. E.g. indigestion, while other might experience more serious side effects like hallucinations, erection problems and raised blood pressure. BZs are renowned for being highly addictive and can also cause increased aggression and long-term memory impairments. Consequently, these side effect diminish the effectiveness of drug treatments, as patients will often stop taking medication if they experience these side effects. Dependency/addiction may also occur.
- BIOLOGICAL TREATMENTS ARE SHORT-TERM ORIENTATED, AS TEHY DONT TREAT THE UNDERLYING CAUSE OF OCD
Finally, drug treatments are criticised for treating the symptoms of the disorder and not the cause. Although SSRIs work by increasing the levels of serotonin in the brain, which reduces anxiety and alleviates the symptoms of OCD, it does not treat the underlying cause of OCD. Furthermore, once a patient stops taking the drug, they are prone to relapse, suggesting that psychological treatments may be more effective, as a long-term solution.
• Delayed effects of drugs (3-4 weeks to kick in) - patients may give up and look to other treatment options.
• Not all cases of OCD may be biological in origin, e.g. influence of trauma, etc (EXPOSURE RESONSE THERAPY MAY WORK BETTER FOR SOME PATIENTS).
