Trajectories of Anhedonia Symptoms after Traumatic Injury

Anhedonia describes the inability or difficulty of experiencing or seeking pleasure. Previous research has demonstrated a relationship between posttraumatic stress disorder (PTSD) or experiencing trauma and anhedonia symptoms; however, little to no work has been done to understand the evolution of anhedonia symptoms after trauma. We aimed to identify anhedonia trajectories following traumatic injury. One hundred ninety-five participants were recruited from the emergency department of a Level-1 Trauma Center after experiencing a traumatic injury. To measure anhedonia symptoms, participants completed the Snaith-Hamilton Pleasure Scale (SHAPS) at 2-weeks, 3-months, and 6-months post-injury. Using latent class mixture modeling, we ran a trajectory analysis with three timepoints of SHAPS scores and compared mental and physical health outcomes across trajectories. Most of the sample fell in the resilient trajectory (85%), while the remainder were in a remitting trajectory (7%) where symptoms decreased over time, and a delayed (6%) trajectory where symptoms did not emerge until 3-months after injury. In the resilient trajectory, there was consistently low levels of PTSD, pain, depression, and anxiety relative to the other trajectories. In the delayed trajectory, depression and PTSD were chronically elevated and pain levels were consistent but mild. In the remitting trajectory, PTSD and depression symptoms decreased over time. Identified anhedonia trajectories mirrored trajectories commonly reported for PTSD symptoms after injury. Evaluating anhedonia trajectories and how they relate to mental health outcomes may inform targeted interventions for traumatic injury patients.