While neuropharmacology may sound like a fringe field of medical science, it is probably the philosophically most central part of all biology.
Why should I make such a far-reaching assessment?
It is my firm opinion that our "self" is first of all what we think. My limbs are not my true self. They can be cut of, and I am still myself, the same person I used to be, though in a more dilapidated housing. And transplant surgery could replace pretty much every organ without changing a person's self.
Except for the brain.
So why would I consider neuropharmacology so central, and not psychology?
The reason is an approach based on a materialistic philosophy. Everything that is, is based on its existence in the physical world. Not just that. Everything that is, is as it is because of its physical form.
Glass breaks easily because of the specific constellation of the atoms making up glass. Few readers would dispute this statement.
But the short article you are reading here, and each word in it, also has its specific physical representation, not just as English language sentences written as htm file, but also as neurochemical constellation in the brain of the writer.
An htm-encoded sentence is easily analyzed, but we are centuries away from producing in test subjects the thinking of a specific sentence by inducing specific neurochemical constellations.
Neuropharmacology is the first, albeit crude, step in realizing the potential of influencing the material constellation of the brain in order to produce a specific way of thinking. In a far advanced stage, neuropharmacology will be much more specific in inducing states of mind, including the one called happiness.