Table 1 Inclusion and Exclusion Criteria

Age ≥ 18 and able to provide written informed consent

Already taking NAC, selenium or vitamin E

History of anaphylactic reaction to NAC

Current PTSD

Meets criteria for DSM-5 diagnosis of PTSD according to CAPS-5 monthly version

Known or suspected clinically unstable systemic medical disorder

History of epilepsy

Current asthma

Recent gastrointestinal ulcers

Treatment resistant PTSD defined as

(a) Minimum 1x trial of an antidepressant (SSRI or SNRI) for minimum 6 weeks without adequate response OR (b) completed a course of trauma-focused psychotherapy

Currently pregnant or breastfeeding

Planning to conceive a child during the trial or 3 months following

If currently taking an antidepressant medication

• Minimum of 6-weeks if recently initiated

• Dose must be stable for minimum 2 weeks

History of psychotic illness