Digital Public Defence: Arne Jan Hjemsæter

Cand.Psychol. Arne Jan Hjemsæter at Institute of Clinical Medicine will be defending the thesis The long-term course of patients with substance use disorders and co-occurring mental disorders – A longitudinal cohort study of patients entering specialized treatment for substance use disorders in 1997 and 1998 for the degree of PhD (Philosophiae Doctor).

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Photo: Frøy Lode Wiig, NKROP

The public defence will be held as a video conference over Zoom.

The defence will follow regular procedure as far as possible, hence it will be open to the public and the audience can ask ex auditorio questions when invited to do so.

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Due to copyright reasons, an electronic copy of the thesis must be ordered from the faculty. In order for the faculty to have time to process the order, it must be received by the faculty no later than 2 days prior to the public defence. Orders received later than 2 days before the defence will not be processed. Inquiries regarding the thesis after the public defence must be addressed to the candidate.

Digital Trial Lecture – time and place

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Adjudication committee

  • First opponent: Professor Mads Uffe Pedersen, Aarhus University
  • Second opponent: Professor Rolf W. Gråwe, Norwegian University of Science and Technology (NTNU)
  • Third member and chair of the evaluation committee: Professor Emeritus Helge Waal, University of Oslo

Chair of the Defence

Professor Reidar Tyssen, University of Oslo

Principal Supervisor

Head of Research Anne Landheim, Innlandet Hospital Trust


A cohort of patients in Norway that entered specialized treatment for substance use disorders (SUDs) in 1997 and 1998 was studied longitudinally. We aimed to (i) investigate and explore the long-term course of substance use, and baseline predictors of having problematic substance use 18 years after entering treatment, (ii) investigate factors associated with levels of mental health distress over the 18 years study time, and (iii) investigate mortality and baseline characteristics associated with the risk of death during the study time.

This was a longitudinal naturalistic cohort study with three measuring points over an observation period of 18 years. In 1997 and 1998, 291 patients entering specialized treatment for SUDs were recruited in a cross-sectional study. A prospective follow-up study was conducted by mailed questionnaire approximately 6 years later (n = 160). This thesis concerns a second prospective follow-up study of the cohort that was conducted by mailed questionnaire to living participants approximately 18 years after baseline (n = 91).

Close to half of the participants in the study had a current problematic substance use 18 years after entering treatment for SUDs. Mental distress at baseline was a predictor of having a current problematic substance use 18 years after treatment. Further, prolonged problematic substance use was associated with greater levels of mental distress over 18 years. Baseline personality disorders, and lifetime affective and lifetime anxiety disorders were also associated with greater mental distress over 18 years. On average, the participants had almost four times higher risk of dying than the general population during the study time. Patients with alcohol use disorder alone died more often from a somatic disease and less often from an overdose compared with patients with poly-SUDs. In addition, men had a significantly higher risk of death than women from an age of 50 years onwards.

Our results show that for many patients, SUDs are long-lasting chronic disorders, that there is a negative association between problematic substance use and mental health over long periods of time and that all these patients have increased risk of premature death. This suggests a need for better preventive measures and improved treatment for patients with SUDs and co-occurring mental disorders in Norway.

Additional information

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Published May 11, 2021 11:44 AM - Last modified June 1, 2021 12:53 PM