Toxicological findings in overdose suicides 2016-21

More than 300 people die from an overdose each year in Norway, and the trend is rising. The proportion of suicides among overdose deaths has been 11-20 % over the past ten years, with the annual figure remaining relatively stable. The purpose of this study was to describe the demographics as well as the medications and substances used in overdose suicides.

Data from forensic toxicology analyses performed at the Department of Forensic Medicine, Oslo University Hospital, were linked to the Cause of Death Registry. The cause and manner of death from the Cause of Death Registry were used to identify overdose suicides in Norway in the period 1 January 2016-31 December 2021.

A total of 1383 overdoses were recorded in the dataset, and suicide was the cause of death in 251/1383 (18.1 %) cases. The average age was 51 years (± 16 years), and 135/251 (54 %) were women. Opioids were found in 235/251 (94 %) cases, with the most common being codeine (67/251; 27 %), oxycodone (63/251; 25 %) and tramadol (60/251; 24 %). In cases where opioids were found, benzodiazepines and/or z-hypnotics were identified in 181/235 (77 %) cases. A total of 109/251 (43 %) had taken antidepressants.

Autopsies following an overdose suicide often revealed more than one psychoactive medication with addiction potential, in addition to an antidepressant. These medications are used for chronic pain, sleep disturbances, anxiety and depression, as well as to treat substance use.