Biological Explanations - OCD Flashcards
What did Strengler and Wenske do?
Investigated the availability of brain serotonin transporters in 10 drug-free OCD and age matched controls
- Used single-photon emission computed tomography
What did Strengler and Wenske find?
Significantly reduced serotonin transport availability found in those with OCD
What does Strengler and Wenske’s study show?
That low serotonin causes OCD
BUT having OCD often leads to depression. Maybe depression is causing low serotonin levels
What does the neuroanatomical explanation suggest?
Genes may work by influencing the brains structure
- structural dysfunction in the central nervous system = OCD
What do the Orbitio-frontal cortex (OFC) and the caudate nuclei (in the basal ganglia) do?
Form a circuit whose function seems to be to convert sensory info into thoughts and actions
What happens to impulses that arise in the OFC?
They are passed to the caudate nuclei which act as filters screening out irrelevant impulses
- most important impulses are passed on to the thalamus
What happens once an impulse has been passed onto the thalamus?
The individual is then driven to think more about the impulse and to take action
What happens when the OFC and caudate nuclei are damaged?
Inappropriate impulses are not suppressed - the individual is overwhelmed by troublesome thoughts and actions = OCD
What did Wise and Rapoport show?
That OCD is often co-morbid with disorders where the basal ganglia are known to be implicated e.g Parkinson’s
= if damage in this area causes Parkinson’s and the individual also has OCD this is the likely cause
What did Piggot et al find?
Results from neuro-imaging studies have been encouraging but inconclusive and the basal ganglia impairment has not always been found in OCD patients when compared to controls
= strong biological evidence against - scientific
What did Cortzer find? (Use if just NA)
OFC or basal ganglia damage, resulting from head injury/illness such as brain tumours can give rise to OCD
= can be environmental damage not just genes which leads to OCD
How does the Neuro Chemical explanation explain OCD?
OCD results from a deficiency in serotonin or a malfunction in serotonin metabolism
What supports the idea that low serotonin can cause OCD?
OCD can be relived by anti-depressants - responds to drugs which affect serotonin rather than other neurotransmitters
How can serotonin act as a neuromodulator?
Regulates other levels of neurotransmitters - disruption of serotonin effects other levels of neurotransmitters
