Dopamine and depression

Neurotransmitters and A Level Psychology

neuralAlthough A Level Psychology students do not need to have an in-depth knowledge and understanding of brain chemistry to get by, it is exceedingly useful to have a reasonable grasp of the concept and functioning of neurotransmitters as Psychologists increasingly seek to explain mental disorders, and human behaviour more generally, at a biochemical level.

Most A Level students know that neurotransmitters are the chemicals that fill the synapses allowing messages to be passed from neuron to neuron around the brain. Most can also name a few neurotransmitters, such as serotonin and dopamine, and link them to a particular behaviour/function (e.g. most students might say that serotonin is a “mood chemical” whilst identifying that dopamine is a “reward chemical”) but when pushed might struggle to say much else. Although students will not be asked to explain what a neurotransmitter is or does in their exam (AQA A), a lack of any additional knowledge might prevent them from fully digesting the theories they encounter that offer explanations at this chemical level or meaningfully critique such explanations.

I came across a useful resource (via Twitter I think) a while ago produced by the Dana Foundation  (“Neurotransmitters: A primer“)  that provides a brief accessible explanation of neurotransmitters making clear that the action of the chemical is not simply dependent on the nature of the chemical itself. After reading this primer it perhaps becomes clearer to the A Level student referring to Serotonin, for example, as a “the mood chemical” is a huge oversimplification that is misleading and likely to limit our understanding of the role of chemicals in disorders such as depression.

Dopamine and depression…?

A blog piece posted on the Scientific American blog written by Scicurious (“The dopamine side(s) of depression” posted on 17/12/2012) discusses some newly published research (published in the journal Nature) pointing towards a key role for dopamine in behaviours associated with depression. Although this is not a brand new idea, the animal-based research under discussion in this recent post highlights the need to consider a range of neural circuits, beyond serotonin, in order to best explain and ultimately treat depression.

Students studying depression as the chosen disorder for AQA A Unit 4 (Psychopathology) may find this article an interesting read and will be able to exercise and refine their critical thinking skills delving into issues such as:

  • the use of animals,
  • the validity of the ways in which “depressive behaviours” have been operationalised,
  • the use of sophisticated techniques such as optogenetics,
  • the implications for other biochemical explanations of depression and treatments,
  • the implications for dopamine-based explanations of other disorders e.g. schizophrenia.

The post also contains an interesting discussion surrounding a finding that was not found to be statistically significant yet despite this the author seems to still see an effect that the statistics simply do not support. Students might like to consider whether dismissing the stats is a sensible thing to do.


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