Mental and behavioural disorders

Data on diagnosed mental and behavioural disorders were retrieved from VEGA and NPR. Perpetrators and controls with at least one diagnosis according to the ICD-10 classification of mental and behavioural disorders (F00-F99) in the month (≤ 30 days) and the year (≤ 365 days) prior to the homicide were included. If an individual had more than one mental or behavioural disorder diagnosis (F00-F99) per date and healthcare setting, only one diagnosis per date and setting was included for further analysis. For the purpose of descriptive analysis, mental and behavioural disorders diagnosed in primary care, specialized outpatient care and inpatient care were categorized as at least one recorded diagnosis in the month prior to the homicide (= 1) or no recorded diagnosis in the month prior to the homicide (= 0). The same applied to mental and behavioural disorders in the different healthcare settings in the year prior to the offence.