suffered severe incident twice; patient exhibited dementia, like a transitional state; she tried to drive caller's car while she was still on her pajamas, but she didn't have the car keys. Patient then went into the kitchen and opened all cupboard doors; Showing a maniac behavior; This spontaneous case was reported by a consumer and describes the occurrence of DEMENTIA (patient exhibited dementia, like a transitional state), ABNORMAL BEHAVIOUR (she tried to drive caller's car while she was still on her pajamas, but she didn't have the car keys. Patient then went into the kitchen and opened all cupboard doors), MANIA (Showing a maniac behavior) and VACCINATION COMPLICATION (suffered severe incident twice) in a 77-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 010MZ0A) for COVID-19 vaccination.     Concurrent medical conditions included Hypothyroidism and Blood pressure high. Concomitant products included HYDROCHLOROTHIAZIDE and SPIRONOLACTONE for Blood pressure high, LEVOTHYROXINE SODIUM (SYNTHROID) for Hypothyroidism.    On 29-Jan-2021, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 30-Jan-2021, the patient experienced DEMENTIA (patient exhibited dementia, like a transitional state), ABNORMAL BEHAVIOUR (she tried to drive caller's car while she was still on her pajamas, but she didn't have the car keys. Patient then went into the kitchen and opened all cupboard doors) and MANIA (Showing a maniac behavior). On an unknown date, the patient experienced VACCINATION COMPLICATION (suffered severe incident twice). On 30-Jan-2021, DEMENTIA (patient exhibited dementia, like a transitional state), ABNORMAL BEHAVIOUR (she tried to drive caller's car while she was still on her pajamas, but she didn't have the car keys. Patient then went into the kitchen and opened all cupboard doors) and MANIA (Showing a maniac behavior) had resolved. At the time of the report, VACCINATION COMPLICATION (suffered severe incident twice) outcome was unknown.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   Sixteen hours after the second dose, on 30-JAN-2021, patient exhibited dementia, like a transitional state. Patient thought she was in a different city and home, and that she tried to drive caller's car while she was still on her pajamas, but she didn't have the car keys. Patient then went into the kitchen and opened all cupboard doors. Patient was showing a maniac behavior, looking for something on her phone and trying to make phone calls. Her daughter gave her something to help her sleep. Patient woke up the next morning and felt completely fine. Onset of symptoms was around 15-16 hours post vaccine.  Total duration of episodes was 12 hours roughly.   This case was linked to MOD-2021-300955, MOD-2021-301074 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 30-Aug-2021: Follow up was received. Additional event- Vaccination complication was added.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the eventa, a causal relationship cannot be excluded. Case downgraded to non-serious due to the lack of evidence of seriousness from a regulatory or clinical standpoint.