The Amazing Complexity of Environmental Research in Psychiatry

In my Psychology Today post of 12/24/12, Why Psychotherapy Outcome Studies are Nearly Impossible, I discussed the large number of variables that are not taken into consideration in those studies which bring any conclusions drawn from them into question. These include variations in therapist techniques that aren’t measured, sampling problems with people that can have wide variations in their proclivities and sensitivities, problems with finding an active control treatment, the lack of double blinding, and lack of complete candor by subjects.

The same types of issues apply to epidemiological research into environmental risk factors for various psychiatric disorders. Most studies try to measure the effect of a single environmental exposure on a single outcome—something that rarely exists in the real world.

In a “viewpoint” article from JAMA Psychiatry published online on June 6, 2018, by Guloksuz, van Os, and Rutten ("The Exposome Paradigm and the Complexities of Environmental Research in Psychiatry"),the authors discuss characteristics of the environment as they do function in the real world. They speak of multiple “networks of many interacting elements…”

Individuals are exposed to these elements as they accumulate over time, so that one single exposure usually means very little. Exposure also is “dynamic, interactive, and intertwined" with various other domains including those internal to individuals, what individuals do within various contexts, and the external environment itself—which is constantly changing. Last but not least, each individual attributes a different, and sometimes changing, psychological meaning to everything that happens to them. This meaning attribution can alter the effect of each environmental exposure dramatically.

Each environmental factor confers risk for a "diverse set of mental disorders." These factors are far from universal so that some people remain completely unexposed to them. They interact with each other so they are not independent. They are time sensitive. They are dose dependent even within similar environments, meaning individuals are not exposed to them at the same level. They can be subject to being confounded by each individual’s differing genetic propensities.

With all that to consider, drawing final conclusions from a few studies just does not cut it as real science. But the field tends to believe in those conclusions as if they were gospel.