A term/idea that has come up on-and-off throughout the history of psychology is "biopsychosocial." It represents a model of mental (and physical) health that emphasizes conceptualizing conditions based on their physiological components (bio), psychological underpinnings (psycho), and the context in which the person lives and the people they interact with (social). At different times it has been considered an ideal model for conceptualizing clients/patients, with Engel (1977) promoting its use over a more traditional medical model (which focuses primarily on biology/physiology).
To many, the use of such a model seems obvious. Yet we see that the field of psychology has had trouble sticking to this view, with there being a more psychosocial focus at times (e.g., during the times of psychoanalysis and the DSM-I/-II) and a new trend of moving towards a biological approach via genetics and the brain mapping project (which echoes the biological focus brought about previously by behaviorists). It can even be said that the tension between the two sides (biological and psychosocial) are remnants of the old argument between nature vs. nurture (i.e., are we a product of our biology [nature], or the experiences we have growing up [nurture]).
But neither of these fully grasps the larger picture of how a person interacts with their surroundings. Genetics and biology play an important role by establishing the base of who we are, but they are not absolute. With our experiences over time, external forces adjust who we are (just look at the "power of the situation" demonstrated by Zimbardo's prison experiment), and our own cognitions influence our physiological reactions (e.g., a fight-or-flight response caused by stress). Therefore, we need to take into account each domain: biological, psychological, and social.
Studies on gene x environment (read: gene by environment) interactions are a decent step towards biopsychosocial understandings of psychology. GxE studies examine how different gene expressions, paired with specific life experiences, result in different likelihoods of mental health problems. But even these studies sometimes focus too heavily on the "bio" and "social" pieces, without incorporating psychological factors.
In terms of research, it gets complicated to fully utilize a biopsychosocial model. Yet, we at least need to be using it as the basis for our conceptualizations. By picking sides and examining behaviors and thought processes from the polar ends, we are not helping ourselves to better understand the reality of what is happening in life. Making sure we stick to a biopsychosocial framework is important for the progress of psychology and medicine.
Engel, G. L. (1977). The need for a new medical model: A challenge for biomedicine. Science, 196(4286), 129–136.