Poster E20, Monday, March 27, 2:30 – 4:30 pm, Pacific Concourse
The association between residual cannabis use and the P300 event related potential on emotion processing in subclinical depression
Robert Torrence1, Joseph Davis1, Lucy Troup1; 1Colorado State University
Cannabis has been suggested to have anxiolytic and antidepressant effects, however research is conflicting. With the recent legalization of cannabis in Colorado, and other states, for medical and recreational purposes, there is a need to better understand the relationship between cannabis use and mood disorders, especially in ecologically valid models. The purpose of this research was to examine the interaction between cannabis use and depression symptoms, when processing emotional expressions. A facial emotion-attention task was completed by 122 participants; neural activity was measured using EEG. The task had three conditions: implicit, explicit, and empathy; and four emotions: neutral, happy, angry, and fearful. Analysis of the P300 was conducted. Participants were classified into four groups: controls, nondepressed users, depressed nonusers, and depressed users. Depressed nonusers had reduced P300 amplitudes when implicitly processing fearful expressions, in comparison to controls. Depressed users had reduced amplitudes when explicitly processing fearful expressions, in comparison to controls. Within-group comparisons indicated that depressed non-users showed reduced P300 amplitudes for negative emotions, in comparison to happy and neutral in the implicit task. They also had reduced P300 amplitudes for angry, in comparison to fear in the explicit task. The largest P300 amplitude differences were found in depressed users, in particular, there was a significantly reduced amplitude in response to fearful faces in the explicit and empathy tasks. The results suggest that cannabis does not positively affect depression and may actually have negative effects on empathy. The results were consistent with past research that suggested cannabis affects empathic processing.
Topic Area: EMOTION & SOCIAL: Emotional responding