primary remitting multiple sclerosis to flare-up; caused a secondary psychosis/  talk to the voices in his head; Could not hold a conversation or pay attention to someone talking; Temper flares; excess energy; This spontaneous case was reported by a health care professional (subsequently medically confirmed) and describes the occurrence of MULTIPLE SCLEROSIS RELAPSE (primary remitting multiple sclerosis to flare-up) and PSYCHOTIC DISORDER (caused a secondary psychosis/  talk to the voices in his head) in a 35-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 027C21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.   Concurrent medical conditions included Psychiatric disorder NOS (Been a psychiatric patient for many years.) and Multiple sclerosis (Being diagnosed with primary relapsing multiple sclerosis.). Concomitant products included CELECOXIB (CELEBREX) for Inflammation, HALOPERIDOL (HALDOL [HALOPERIDOL]) for an unknown indication.  On 08-May-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 09-May-2021, the patient experienced MULTIPLE SCLEROSIS RELAPSE (primary remitting multiple sclerosis to flare-up) (seriousness criterion medically significant), PSYCHOTIC DISORDER (caused a secondary psychosis/  talk to the voices in his head) (seriousness criterion medically significant), DISTURBANCE IN ATTENTION (Could not hold a conversation or pay attention to someone talking), AGGRESSION (Temper flares) and ENERGY INCREASED (excess energy). The patient was treated with HALOPERIDOL (HALDOL [HALOPERIDOL]) at a dose of 2 milligram every 2 hours for a couple of days and HALOPERIDOL (HALDOL [HALOPERIDOL]) ongoing since an unknown date at a dose of 5 milligram three times a day. At the time of the report, MULTIPLE SCLEROSIS RELAPSE (primary remitting multiple sclerosis to flare-up), PSYCHOTIC DISORDER (caused a secondary psychosis/  talk to the voices in his head), DISTURBANCE IN ATTENTION (Could not hold a conversation or pay attention to someone talking), AGGRESSION (Temper flares) and ENERGY INCREASED (excess energy) outcome was unknown.  The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   With in a day or two of receiving his Moderna Covid-19 vaccine, the caller's son had experienced temper flares along with excess energy, could not hold a conversation or pay attention to someone talking to him. His psychiatrist told him to take Haldol (haloperidol) 2mg every 2 hours for a few days, then changed the dose to haloperidol 5mg three times daily. Caller is not sure about son's compliance to his medications, but was snot sure that he was taking them last weekend. The son was doing better than he did last week, emotionally. Mother did not have permission of to talk to psychiatrist or staff, but her son informed her that the psychiatrist felt that the vaccine caused his primary remitting multiple sclerosis to flare-up, which in turn caused a secondary psychosis. Last incident when MS triggered psychosis was 4 years ago. Patient has been stable until the vaccine. Patient's psychosis had caused him  in the past to talk to the voices in his head. He does sometimes get upset with the voices in his head, as sometimes they are angry, but sometimes the voices talk about religion and he works through problems. Patient described his post-vaccine psychosis as "hell". Treatment included haloperidol.  Company Comment: Based on the current available information which shows a temporal association between the use of mRNA-1273 and the onset of the reported events, a causal relationship cannot be excluded.   This case was linked to US-MODERNATX, INC.-MOD-2021-169112 (E2B Linked Report).  Most recent FOLLOW-UP information incorporated above includes: On 25-May-2021: non significant follow up received on 25-MAY-2021; Sender's Comments: Based on the current available information which shows a temporal association between the use of mRNA-1273 and the onset of the reported events, a causal relationship cannot be excluded. US-MODERNATX, INC.-MOD-2021-169112:Crosslinked with the reporter- MOD21-097486 (Daughter's case)