A Biological Model?

     One of the unfortunate aspects of some forms of psychoanalysis is a tendency to think of human beings as "instinctively" driven beings, rather than beings who are interconnected with others since birth. It seems that 'instincts' are these isolated tendencies within a person, when in reality, the way a person experiences emotion is often the result of more than simply inner triggers of emotions in the body.
      I was reading these articles today for my course in Buddhism and mental health, and I came across a few about the relationship between post-traumatic stress and certain kinds of states of being and behavior. The articles were suggesting that post-traumatic stress can profoundly affect the neurochemistry of the brain, resulting in behaviors such as substance abuse or depression. This is all very well, but I couldn't help but notice how the authors seemed to be rooting behaviors in very specific chemical deficiencies in the body. Using a model of 'deficiency' and/or 'imbalance', the authors tried to show correlations between these imbalances and subsequent behaviors. Somehow, I get a sense that these articles are lending themselves to a medical view of life. It's as though all one needed to do to address these problems would be to inject some new chemical which counterbalances the deficiencies which lead to problem behaviors.
       I am somehow reminded that perhaps these scientific explanations are only creations of the mind. If I think in terms of deficiency or imbalance, I no sooner start to become a consumer, whose aim in life is to correct the deficiency--to 'fill the hole' somehow. But then I also started to wonder, is there ever a perfect 'equilibrium' achieved in life, or is perhaps even the concept of balance relative? I am afraid that perhaps the medical view only perpetuates this idea of trying to compensate for deficiencies using some quick fix. Perhaps in reality, nobody fully understands the relationship between the chemicals produced in the body.
       An alternate explanation might be that when a person is only looking through the microscope, they miss out on the larger currents that might be factoring into an experience. But because things might seem more precisely measured when they are small units, we get this idea that they can predict the whole behavior of humans. Yet, most people start to become aware that humans are much more complicated in how they think and behave. Is it fair to focus only on their brain chemistry to understand what really happens with them?