Data from the Norwegian Prescription Registry show that 5 183 persons were prescribed with quetiapine in 2005. In 2018, this number had risen to 63 125 persons (18). Thereby, the one-year prevalence had increased to 1.2 %. These figures also include treatment of psychoses and affective disorders, but the increase is nevertheless considerable. However, no reports of usage problems have been submitted by the departments for addiction treatment. The medical advisor at the Emergency Addiction Services and Detoxification, Oslo University Hospital, has on request reviewed the department's clinical experience and concluded that the department has not registered any increased prescribing of or demand for quetiapine. In exceptional cases the department has encountered patients who have been prescribed with, or despite regular prescribing have used 'supratherapeutic' doses, but they have no information on patients having obtained quetiapine from others (P. Krajci, personal communication).
The heads of units that provide drug-assisted rehabilitation convene twice annually to discuss experiences. At the last session (2–3 December 2019) only one of a total of twenty units reported having encountered a wish for increased dosage. All the others reported exclusively problem-free, though often moderately beneficial use. The LASSO programme (drug-assisted harm-reducing substitution treatment in Oslo), which provides a low-threshold option for persons with addiction disorder in central Oslo, does not know of any patients who have requested this drug. This suggests that there is little demand for it in the central Oslo drug scene.
Norway has relatively high overdose mortality. 95 % of the autopsies after such deaths take place at the Department of Forensic Medicine, Oslo University Hospital. Its annual statistics provide information about the findings (19). The number of deaths where antipsychotics were detected increased considerably from 2009 to 2015, but not in subsequent years. In 2018 a little more than 2 000 investigations were carried out, and intoxicants or pharmaceutical drugs were detected in somewhat more than 1 500 of these. Olanzapine was found in 3 % and quetiapine in 4 % of the examinations (H.M. Edvardsen, Department of Forensic Pathology and Clinical Forensic Medicine, Oslo University Hospital, personal communication). In a large-scale Nordic study from 2012, quetiapine was not deemed to be the man intoxicant in any of 194 cases of overdose deaths in Norway. The substance was later detected in seven persons (3.6 %), but it was not known whether this was due to prescribed treatment (20).