psychopathology - ocd biological approach Flashcards
what is one form of biological explanation for OCD
the genetic explanation
Genes are involved in vulnerability to OCD.
who observed OCD patients
Lewis (1936)
37% had parents with OCD and 21% had siblings with OCD.
what did lewis study suggest
genetic vulnerability to OCD runs in families
what dose the diathesis stress model say about OCD
certain genes leave some people more likely to develop a mental disorder
Environmental stress needed to trigger this.
what are candidate genes
specific genes which create a vulnerability for OCD,
one example of a candidate gene for OCD
serotonin genes - implicated in the transmission of serotonin across synapses (NEUROTRANSMITTER)
Dopamine genes
what dose the genetic explanation say OCD is
polygenetic
who study polygenetic genes in OCD
Taylor (2013)
up to 230 different genes may be involved in OCD.
Describe different types of OCD
aetiologically heterogeneous, meaning that the origins of OCD vary from one person to another.
STRENGTH OF THE Genetic explanation
strong evidence base
Nestadt et al. reviewed twin studies
found that 68% of identical twins (MZ) shared OCD
31% of non-identical twins (DZ).
Marini and Stebnicki - person with a family member with OCD is around four times as likely to develop it as someone without.
people who are genetically similar are more likely to share OCD, supporting a role for genetic vulnerability.
LIMITATION OF THE genetic explanation
existence of environmental risk factors.
environmental risk factors that trigger or increase the risk of OCD.
Cromer et al. (2007) - one sample over half of people with OCD experienced a traumatic event. OCD severely correlated positively with a number of traumas.
describe the role of seretonin in OCD
believed to help regulate mood.
responsible for relaying information from one neuron to another. (The Basal Ganglia to the obitolfrontal cortex to motor area.)
what happens if a person has low seretonin
normal transmission of mood-relevant information does not take place, mood is affected
ocd - explained by a reduction in the functioning of the serotonin system in the brain.
how dose the decision making process work
associated with abnormal functioning of the lateral (side bits) frontal lobes of the brain.
frontal lobes are responsible for logical thinking and decision making.
strength of the neural model of OCD
supporting evidence
Antidepressants that work on serotonin reduce OCD symptoms. This suggests that serotonin may be involved on OCD.
OCD symptoms form part of conditions that are known to be biological in origin, such as Parkinson’s disease