What are threshold symptoms and sub-threshold symptoms?

Question

I've come across these terminologies—*threshold symptoms* and *sub-threshold symptoms*—in one of the papers in psychology where *delayed reactions* are introduced: >Empirical studies that have mapped PTSD symptoms over time in fact observed what appear to be delayed elevations in the direction of threshold symptoms... However, I don't have any ideas what those words are all about.

Answer 1

Typically, those identified as experiencing "sub-threshold symptoms" do not meet full clinical criteria for a PTSD diagnosis. For example, one may experiences two or three symptoms from criterion B-E. Keep in mind that there is not a consensus regarding the optimal definition of "sub-threshold" as it relates to diagnosis. I am inclined to understand the use of "delayed reactions" to mean "delayed onset" instead. This is to mean that individuals who experience traumatic events may not experience symptom onset right away. So, "delayed elevations in threshold symptoms...." would basically be saying people experience a trauma, report "sub-threshold" symptoms that do not meet full criteria, and over time experience elevations in previously identified symptoms (and/or the reporting of symptoms from other categories) that later meet full criteria for a clinical diagnosis.