Criminal Behavior in the Four Years Preceding Diagnosis of Neurocognitive Disorder: A Nationwide Register Study in Finland

•What is the primary question addressed by this study? Do patients with neurocognitive disorders commit crimes before they receive a dementia diagnosis?•What is the main finding of this study? In this Finnish nationwide register study of 92 191 patients with Alzheimer's disease, frontotemporal dementia, or Lewy body dementias, the female and male criminality rates were higher in the AD and FTD groups than in the general same-aged population in the four years preceding diagnosis.•What is the meaning of the finding? Novel criminal behavior may be associated with developing dementia, in which case diagnostics for neurocognitive disorder is warranted.