Acute delirium and altered disruptive behaviour in an acute hospital setting despite the use of sedative agents is the most common indication for emergency unplanned intubations. Most of these patients are empirically treated for encephalitis whilst awaiting imaging and Cerebrospinal Fluid (CSF) and Polymerase Chain Reaction (PCR) tests. However, the increasing prevalence and legalisation of cannabis globally amongst young patient cohort have raised concerns regarding its long-term impact on brain health. Chronic cannabis use has been linked to frontal lobe atrophy, which can lead to significant cognitive and behavioural impairments, including early onset frontotemporal dementia (FTD). This case report presents a patient with frontal temporal lobe brain atrophy due to prolonged cannabis use presenting with altered disruptive behaviours and delirium, detailing diagnostic processes, management strategies, and implications for healthcare systems like the NHS. The article distinguishes between medical and recreational cannabis use, highlighting their distinct health outcomes. Frontotemporal dementia (FTD) is increasingly recognized as an underdiagnosed condition that often presents earlier than other dementias, such as Alzheimer’s disease. The association of FTD with chronic cannabis use, particularly among younger patients, introduces unique challenges. It is essential to investigate the burden of cannabis induced FTD to inform future research and guide the allocation of healthcare resources for this uncharted issue. The “iceberg effect” of underreported cannabis-related neurological disorders complicates diagnosis and treatment, necessitating enhanced diagnostic vigilance and comprehensive epidemiological studies. This report aims to increase awareness among critical care and emergency care clinicians about the potential neurotoxic effects of chronic cannabis use, highlight limitations of current health care, scope for the future demands on the NHS and emphasise the need for early intervention and tailored healthcare approaches in managing cannabis-related neurocognitive disorders.