Effect of Nitrous Oxide on Aggression.

Inclusion Criteria:

All participants:

* Between 21 and 55 years of age.
* Physically healthy (no clinically significant medical condition as confirmed by medical history/physical exam).
* Able to give informed consent.

Aggressive (IED) Study Participants (n = 25 Completed; 75 Enrolled).

* Current DSM-5 Criteria for IED
* LHA Aggression scores \> 12
* Negative for a history of psychosis, bipolar disorder, developmental disorder, intellectual disability or a current substance use disorder.

Healthy, Non-Aggressive, Controls (n = 25 Completed, 75 Enrolled).

* Do not meet current/lifetime DSM-5 Criteria for any psychiatric disorder
* LHA aggression scores \< 12

Exclusion Criteria:

* PCL Screening Version Score \> 13; i.e., subject is likely to be psychopathic.32
* Current DSM-5 Major Depressive Episode.
* Life history of bipolar disorder/schizophrenia/organic mental syndrome.
* Intellectual disability \[i.e., IQ \< 70\].
* History of N2O abuse/dependence.
* Clinically significant medical condition.
* Current alcohol/drug use disorder of moderate or severe severity (i.e., subject is not in full remission from moderate to severe alcohol/drug use).
* Two weeks free of antipsychotic medication. (Note: Because a large number of individuals with aggressive tendencies in the community are already taking SSRIs, SNRIs, or mood stabilizers, these individuals will not be excluded if they continue to report impulsive aggressive behaviors at time of study.)
* Unwilling/unable to sign informed consent document.