Nabilone for Agitation in Frontotemporal Dementia

Inclusion Criteria: * Men and women over 18 years * Major neurocognitive disorder due to probable behavioural variant FTD (Rascovsky criteria)17 or primary progressive aphasia (Gorno-Tempini criteria)18. All ages and severity levels will be included. * Meets International Psychogeriatric Association criteria for agitation in cognitive disorders19 * CMAI score of 39 or above * Stable psychoactive medication for 2 weeks prior to screening (all medications allowed) with no intention to change dose during treatment period * Available study partner with ≥10 hours per week in-person contact with the patient. This can either be a friend/family member or a staff member at an assisted living facility. * Capacity to provide written consent in English or French, or consent from official surrogate decision maker in case of incapacity Rationale for Inclusion Criteria: The inclusion criteria are designed to enroll patients with FTD with the behaviours of interest, with a range of disease severity that will permit assessment of all outcome measures. Exclusion Criteria: * Clinically significant psychotic symptoms (Neuropsychiatric Inventory domain score (severity x frequency) ≥4 on the delusions or hallucinations subscale) * Clinically significant orthostatic hypotension (a decrease in systolic blood pressure of 20 mm Hg or in diastolic blood pressure of 10 mm Hg within three minutes of standing compared to blood pressure in a seated position) * Symptomatic orthostatic tachycardia (heart rate increase from of at least 30 beats per minute within the first 5 minutes of standing compared to a seated position IF orthostatic hypotension is not a problem) * Unstable cardiovascular condition in the opinion of the investigator * Known or suspected history of drug or alcohol dependence or abuse in the past 12 months, including use of any psychomimetic drugs (e.g. ketamine, lysergic acid diethylamide, psilocybin). * Allergy, or significant adverse reaction to cannabinoids. If the adverse reaction involved psychological symptoms that are indicative of psychosis or severe anxiety the patient will be excluded. Their treating clinician may be consulted for a clinical opinion on the severity of the response to cannabis and whether this justifies exclusion from the trial. * Major depressive episode within 6 months of screening * Women who are breast feeding or pregnant * Severe liver dysfunction, as determined by their treating clinician * Other psychiatric or neurological condition that could cause significant agitation * Ongoing use of any cannabinoid-related products. This includes any THC or CBD based products, regardless of administration method (oral, inhalation, topical, etc…) Rationale for Exclusion Criteria: The exclusion criteria are designed to avoid inclusion of patients who may have medical comorbidities that would increase their risk of serious side effects from repeated nabilone administration.