The biological approach to explaining OCD

• What is the biological approach?

  -It explains mental health conditions as being due to faulty physical processes

  -This explanation includes the physical structure of your DNA, inherited from your parents
• What is the genetic explanation as an approach to explaining OCD?

  Genetic explanation

  -There is no one OCD gene; however, its thought a vulnerability or predisposition to OCD is inherited from parents.

  -Genetic analysis has revealed around 230 separate "candidate

  genes" found more frequently in people with OCD; many

  candidate genes influence the functioning of neural systems in

  the brain; for example, the SERT gene affects reuptake in the

  serotonin system. Other identified genes include gene 9, COMT gene, and 5HT1-D beta gene.

  -As so many candidate genes have been identified, this suggests OCD is polygenic, meaning a predisposition to OCD requires a range of genetic changes.
• What is the neural explanation for OCD?

  Neural explanations for OCD: include biochemical causes, an imbalance of neurotransmitters (chemicals that communicate

  information between neurons) and the large neural structures in the brain that are made of many neurons (cells).
• What is the neural explanation as an approach to explaining OCD?

  Serotonin

  -Low serotonin levels are thought to cause obsessive thoughts,

  and the low level of serotonin is likely due to it being removed

  too quickly from the synapse before it has been able to

  transmit its signal / influence the postsynaptic cell.

  -Serotonin and other neurotransmitters are chemical

  messengers; presynaptic neurons release neurotransmitters,

  and receptors on the postsynaptic neuron detect these; if the

  signal is strong enough, then the message is passed on, the

  neurotransmitters detach from the receptors and are taken

  back to the presynaptic neuron through a process

  called reuptake.

  -It seems this process happens too quickly in

  people with OCD, leading to reduced serotonin levels in the

  synapse.

  -The SERT gene is the gene responsible for serotonin

  transportation in the synapse.
• Evaluation - Scientific

  -One strength of the approach is that it may be seen as 'scientific'.

  -This means the biological approach focuses on observable, measurable biological features.

  -For example, many modern techniques such as MRI brain scans have revealed that some OCD patients appear to have brain abnormalities such as a loss of tissue in the frontal lobes of the brain which could indicate brain abnormality plays a part in the disorder.

  -This is positive because it enables the approach to be empirically tested.
• Evaluation - Simplistic

  -However, the approach may be criticised for being biologically reductionist:

  -This means the approach reduces the complex issue of mental health down to its most basic parts such as genes, and ignores the role that the environment may play.

  -For example, although concordance rates are often found to be higher in MZ than DZ twins for OCD, the fact concordance rates are not 100% in MZ twins suggests other factors must also play a part.

  -This is a problem as the biological approach to OCD may be too simplistic.