Of the dozens of neurotransmitters that have been discovered, how many appear to be especially important in mental disorders?

Of the dozens of neurotransmitters that have been discovered 4 appear to be especially important in mental disorders.

Explanation:

The signal from one neuron is passed to another neuron with the help of a neuron transmitter. The signal that is produced by one neuron must be responded by another neuron. The receptor of neuron are bounded by the neuron transmitters.

Pre synaptic neurons are those that helps in releasing the neuron transmitters. Postsynaptic neurons are those that are helpful in receiving these neuron transmitter signals. The signals that are also released by neurons in the direct that are in reverse to the above mentioned steps. In metal disorders 4 neuron transmitters are considered to be very important.