OCD characteristics and causes

• Obsessions 


  Persistent and recurrent thoughts or impulses which cause anxiety - may be frightening or embarrassing

  examples : need for symmetry , fear of germs
• Compulsions 


  Repetitive behaviour or mental acts that the person feels driven to perform response to an obsessions , performing this usually lowers anxiety

  examples : counting rituals, ritualistic hand washing
• Frequently obsessions and compulsions are related

  however the compulsion does not always follow logically from the obsession
• Emotional characteristics 


  =feelings OCD causes

  obsessions and compulsions are a course of anxiety and stress

  sufferers are aware that their behaviour is excessive , causing feelings of embarrassment and shame
• Cognitive characteristics 


  =obsessions are the cognitive characteristics of OCD

  they are uncontrollable and person recognises that they are unreasonable
• Behavioural characteristics 


  =compulsions are the behavioural characteristics of OCD
• Causes of mental illness 


  1-genes

  2-neural explanations (chemical imbalance and neuroanatomy)
• Genetics 


  Individuals inherit specific genes from their parents that are related to the onset of OCD
• Neurotransmitters 


  Released from vehicles at synapses to allow neurons to signal to eachother
• Serotonin 


  Inhibitor and related to mood and happiness
• Dopamine 


  Excitatory and related to motivation and reward
• OCD genes 


  COMT gene may contribute

  regulated production of dopamine

  one Form of the COMT gene is more common in OCD patients than not

  variation produces lower activity of the COMT gene which causes higher dopamine
• SERT gene 


  Also linked to OCD

  affects the transport of serotonin, creating lower levels of the transmitter
• Polygenic 


  Taylor (2013) found evidence that their might be up to 230 different genes involved in OCD

  means it’s not caused by a single gene, there are several involved
• Evaluation, testing 


  Family studies - if genetic should expect more than one family member to have the same disorder

  twin studies - compare twins to see if both twins have same disorder
• Chemical imbalance 


  Genes code for levels of neurotransmitters in the brain

  these chemicals transmit signals between nerves

  in mental illness levels of neurotransmitters in brain too high or too low
• Serotonin and dopamine 


  Low levels of serotonin (SERT) and high levels of dopamine (COMT)

  abnormal levels are thought to cause malfunctions in parts of the brain (neuroatonamy)
• Neuroatonomy 


  serotonin plays a key role in the operation of the OFC therefore abnormal levels of serotonin may cause this area to malfunction

  dopamine is also linked, high levels lead to over activity in whole area of brain
• Areas of brain 


  Frontal lobe - decision making and logical thinking

  OFC is involved in decision making and worry about behaviour

  a malfunction of OFC would result in increased anxiety and planing to avoid anxiety (obsessions)

  thalamus - cleaning, checking and other safety behaviour

  overactive thalamus results in increased motivation to clean out to check for safety (compulsions)
• Strength 


  Brain activity - supporting evidence from PET scans of patients with OCD

  scan taken while symptoms are active and she heightened activity of OFC
• Strength 


  Drug treatment

  drug treatments which increase serotonin activity have been found to decrease OCD symptoms - supporting the neuro explanation

  also ha s implications for providing effective treatments for OCD
• Weakness


  Reductionist

  reduces complex causes to just biological factors
• Weakness 


  Deterministic - removes responsibility and makes patient feels powerless

  theory implies that if you have a COMT/SERT gene and the over reactive neuroatonamy you WILL experience OCD, removing free will from the patient
• Diathesis stress model

  this is a better explanation as it argues need both a biological vulnerability and environmental trigger

  supporting evidence - Cromer et al

  over half of OCD patients in their sample had suffered from a traumatic event in their past