Provided herein are methods for preventing or treating post-traumatic stressdisorder (PTSD) in asubject, the methods including: administering an agent which inhibitsformation of aglucocorticoid receptor (GR) - FK506 Binding Protein 51 (FKBP51) complex (GR-FKBP51complex), or which disrupts already formed GR-FKBP51 complex, to the subject；therebyreducing a level of GR-FKBP51 complex in the subject and preventing ortreating the PTSD.Also provided are methods for diagnosing a subject as having, or being at riskof developing, aPTSD, the methods including steps of: measuring a level of a GR-FKBP51 complexin thesubject； comparing the measured level to a reference level of a non-PTSDcondition； andidentifying the subject as having, or being at risk of developing, PTSD wherethe measured levelis elevated relative to the reference level. Agents, compositions, and/or kitsfor the diagnosisand/or treatment of PTSD are also described.
