Biochemical explanations of mental illness

Question 1

Background research for depression, Young and Leyton (2002)

Answer 1

Young and Leyton (2002) showed that when participants were given a substance to reduce brain serotonin, they experienced low mood.

Question 2

Background research for depression, Sachs et. al. (2015)

Answer 2

Sachs et. al. (2015) showed that mice with a genetic tendency for serotonin deficiency exhibited depressed symptoms when exposed to social stress.

Question 3

What is the biochemical explanation of mental illness?

Answer 3

Mental illness is caused by abnormal levels of neurotransmitters. Neurotransmitters are neurochemicals made by the body. From a pre-synaptic neuron they are neurotransmitted across a synapse to the receptor sites of a post-synaptic neuron. Whether they activate the receptors is dependent on the quantity of neurotransmitter. Mental illness can result from diminished and increased amounts of neurotransmitter binding to receptor sites. Depression is caused by a low quantity of serotonin, a neurochemical that controls the activity of dopamine (rewards) and noradrenaline (mood and activity levels)

Question 4

Evaluation of drug treatments to eliminate biochemical induced causes of mental illness

Answer 4

The success of drug treatment supports the biochemical explanation by reducing symptoms through restoring chemical balance. This suggests that the cause was biochemical, however this shows the aetiological fallacy (the mistaken belief that the effectiveness of a form of treatment indicates the cause of a disorder)

Question 5

Limitations of the biochemical explanations of mental illness?

Answer 5

• Unable to establish cause and effect. Abnormal levels of neurotransmitters may be a symptom of mental illness rather than a cause
• Medical treatment does not work for all patients due to individual differences, whilst ignoring social and environmental factors
• Deterministic as it suggests that a chemical imbalance will cause mental illness. It can be argues that not all individuals with mental disorders have abnormal levels of neurotransmitters and not everyone with a chemical imbalance develops a mental illness