Neurotransmitters

Neurotransmitters are chemical messengers that transmit signals across the synapse from one neuron to another. Different neurotransmitters have different effects on the body and mind. For GCSE Psychology, you need to know about three key neurotransmitters: serotonin, dopamine, and adrenaline (also called epinephrine).

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Serotonin

Serotonin is a neurotransmitter that plays a key role in regulating mood, sleep, appetite, and emotional well-being.

Function	Description
Mood regulation	Adequate serotonin levels are associated with feelings of well-being and happiness
Sleep	Serotonin is involved in regulating the sleep-wake cycle
Appetite	Influences feelings of hunger and satiety
Social behaviour	Affects social interactions and impulse control

Serotonin and Depression

Low levels of serotonin are associated with depression:

• Selective Serotonin Reuptake Inhibitors (SSRIs) — such as fluoxetine (Prozac) — are antidepressant drugs that work by blocking the reuptake of serotonin in the synapse
• This leaves more serotonin available in the synapse, increasing its effect on the post-synaptic neuron
• SSRIs are one of the most commonly prescribed treatments for depression

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Dopamine

Dopamine is a neurotransmitter involved in reward, motivation, pleasure, and movement.