The use of quantitative, laboratory-based measures of threat in humans for proof-of-concept studies and target development for novel
drug discovery has grown tremendously in the last 2 decades. In particular, in the field of
posttraumatic stress disorder (
PTSD), human models of fear conditioning have been critical in shaping our theoretical understanding of fear processes and importantly, validating findings from animal models of the neural substrates and signaling pathways required for these complex processes. Here, we will review the use of laboratory-based measures of fear processes in humans including cued and contextual conditioning, generalization, extinction, reconsolidation, and reinstatement to develop novel
drug treatments for
PTSD. We will primarily focus on recent advances in using behavioral and physiological measures of fear, discussing their sensitivity as biobehavioral markers of
PTSD symptoms, their response to known and novel
PTSD treatments, and in the case of d-
cycloserine, how well these findings have translated to outcomes in clinical trials. We will highlight some gaps in the literature and needs for future research, discuss benefits and limitations of these outcome measures in designing proof-of-concept trials, and offer practical guidelines on design and interpretation when using these fear models for
drug discovery.