It has been suggested that mGluR5 dysregulation in the orbitofrontal cortex may explain the higher prevalence of impulsive behaviours (i.e., self-harm, aggression and alcohol abuse) as well as suicidal ideation in individuals with PTSD, indicating a role for glutamatergic excitation in emotional dysregulation [134,139,140]. Here, GRM5 is linked to post-traumatic stress disorder.