Research suggests that neuroinflammation of the brain has a role in dementia by activating glial cells and then releasing proinflammatory agents and lipopolysaccharide (LPS) responsible for cognitive deficits [1-3]. Other authors suggest that there is no clear evidence if neuroinflammation after a generalised infection is a cause, agent, or consequence of Alzheimer’s Disease (AD) with bacterial LPS acting on neurones and microglia [4,5]. The current case report refers to a 64-year old lady who developed symptoms of dementia and psychosis a month after she was operated for a duodenal perforation resulting in pneumoperitoneum and generalised bacterial sepsis. Past psychiatric history was negative, and former cognitive deficits were non-existent before the systemic inflammation. At the assessment, brain Magnetic Resonance Image presented mild to moderate supratentorial small vessel disease and mild cortical and subcortical atrophy (Figure 1). Addenbrooke’s ACE-III total score was 74/100 (more affected were memory, fluency and visuospatial) also after the underlying depression was stabilised. The patient became doubly incontinent and started misplacing objects in her kitchen, confusing the use of familiar objects, and having difficulties in word finding. The Bristol Activity of Daily Living was 10/60. The comprehensive neurocognitive assessment resulted in good episodic memory, poor attention, misplacing objects, social phobia, and subjective memory problems with the inability to complete routine tasks. The psychiatric presentation included believing that her food was poisoned, that one of her daughters was a fake, deeming that people on the road were making derogatory comments about her and passing her intrusive thoughts, and thought block. Passivity experiences consisted of thinking that passers-by were able to interfere with her mind or command her to harm herself. She also had auditory-commanding hallucinations to harm herself, believing deriving from people passing by her house. Other auditory hallucinations included hearing people walking on the stair of her home, hearing someone knocking on the door of her bedroom when no one was there, and tactile hallucinations as if someone was tapping on her shoulders when she was alone in her room. We posed the diagnosis of AD and psychosis. After several months, the presentation remains unchanged. In conclusion, the authors of the current research speculate that in the case described, systemic inflammation enduringly unlocked dementia, cognitive deficits, and psychosis [6]. The mediator of the unlocking process could be a hypothetical Alzheimer Triggering Factor linked to the microglia activated by LPS which causes a cascade of processes leading to irreversible dementia (Figure 2).