Neural explanation

• Neural explanations - The view that physical and psychological characteristics are determined by the behaviour of the nervous system, in particular the brain as well as individual neurons
• Abnormal levels of neurotransmitters:

  Dopamine levels are thought to be abnormally high in people with OCD

  Szechtman (1998): Animal study

  • High doses of drugs that enhance levels of dopamine induced stereotyped movements resembling the compulsive behaviours found in OCD patients 
• Abnormal levels of neurotransmitters:

  Lower levels of serotonin are associated with OCD

  • Pigott (1990): Antidepressant drugs that increase serotonin activity have been shown to reduce OCD symptoms 
  • Jenicke (1992): Whereas, antidepressants that have less of an effect on serotonin do not reduce symptoms of OCD 
• Serotonin - Helps regulate mood
• Neurotransmitters are responsible for relaying information from one neuron to another
• Neural explanation: Low levels of serotonin

  • If a person has low levels of serotonin then normal transmission of mood-relevant information does not take place and a person may experience low moods
• Neural explanation: Abnormal brain circuits

  Several areas in the frontal lobes of the brain are thought to be abnormal in people with OCD
• Frontal lobes - The front part of the brain that are responsible for logical thinking and making decisions
• Neural explanation: Abnormal brain circuits

  • The caudate nucleus normally suppresses signals from the orbitofrontal cortex (OFC). In turn, the OFC sends signals to the thalamus about things that are worrying eg potential germ hazard
  • When the caudate nucleus is damaged, it fails to suppress minor ‘worry’ signals and the thalamus is alerted, which in turn sends signals back to the OFC, acting as a worry circuit