Petter Andreas Ringen

  • Researcher
 

Publications 2018

Faerden A, Lyngstad SH, Simonsen C, Ringen PA, Papsuev O, Dieset I, Andreassen OA, Agartz I, Marder SR, Melle I (2018)
Reliability and validity of the self-report version of the apathy evaluation scale in first-episode Psychosis: Concordance with the clinical version at baseline and 12 months follow-up
Psychiatry Res, 267, 140-147
DOI 10.1016/j.psychres.2018.05.065, PubMed 29906681

Holth F, Walby F, Røstbakken T, Lunde I, Ringen PA, Ramleth RK, Romm KL, Tveit T, Torgersen T, Urnes Ø, Kvarstein EH (2018)
Extreme challenges: psychiatric inpatients with severe self-harming behavior in Norway: a national screening investigation
Nord J Psychiatry, 72 (8), 605-612
DOI 10.1080/08039488.2018.1511751, PubMed 30348040

Ringen PA (2018)
Psychiatry- where you are, where do you go?
Tidsskr. Nor. Laegeforen., 138 (3), 263-267

Ringen PA (2018)
[Psychiatry – where do you stand, where are you going?]
Tidsskr Nor Laegeforen, 138 (3)
DOI 10.4045/tidsskr.17.0936, PubMed 29411575

Ringen PA, Faerden A, Antonsen B, Falk RS, Mamen A, Rognli EB, Solberg DK, Andreassen OA, Martinsen EW (2018)
Cardiometabolic risk factors, physical activity and psychiatric status in patients in long-term psychiatric inpatient departments
Nord J Psychiatry, 72 (4), 296-302
DOI 10.1080/08039488.2018.1449012, PubMed 29523041

Ringen PA, Falk RS, Antonsen B, Faerden A, Mamen A, Rognli EB, Solberg DK, Martinsen EW, Andreassen OA (2018)
Using motivational techniques to reduce cardiometabolic risk factors in long term psychiatric inpatients: a naturalistic interventional study
BMC Psychiatry, 18 (1), 255
DOI 10.1186/s12888-018-1832-6, PubMed 30111298

Publications 2017

Aas M, Melle I, Bettella F, Djurovic S, Le Hellard S, Bjella T, Ringen PA, Lagerberg TV, Smeland OB, Agartz I, Andreassen OA, Tesli M (2017)
Psychotic patients who used cannabis frequently before illness onset have higher genetic predisposition to schizophrenia than those who did not
Psychol Med, 48 (1), 43-49
DOI 10.1017/S0033291717001209, PubMed 28967348

Publications 2016

Kvitland LR, Ringen PA, Aminoff SR, Demmo C, Hellvin T, Lagerberg TV, Andreassen OA, Melle I (2016)
Duration of untreated illness in first-treatment bipolar I disorder in relation to clinical outcome and cannabis use
Psychiatry Res, 246, 762-768
DOI 10.1016/j.psychres.2016.07.064, PubMed 27814886

Ringen PA, Nesvåg R, Helle S, Lagerberg TV, Lange EH, Løberg EM, Agartz I, Andreassen OA, Melle I (2016)
Premorbid cannabis use is associated with more symptoms and poorer functioning in schizophrenia spectrum disorder
Psychol Med, 46 (15), 3127-3136
DOI 10.1017/S0033291716001999, PubMed 27534999

Publications 2015

Helle S, Ringen PA, Melle I, Larsen TK, Gjestad R, Johnsen E, Lagerberg TV, Andreassen OA, Kroken RA, Joa I, Ten Velden Hegelstad W, Løberg EM (2015)
Cannabis use is associated with 3years earlier onset of schizophrenia spectrum disorder in a naturalistic, multi-site sample (N=1119)
Schizophr Res, 170 (1), 217-21
DOI 10.1016/j.schres.2015.11.027, PubMed 26682958

Kvitland LR, Melle I, Aminoff SR, Demmo C, Lagerberg TV, Andreassen OA, Ringen PA (2015)
Continued cannabis use at one year follow up is associated with elevated mood and lower global functioning in bipolar I disorder
BMC Psychiatry, 15, 11
DOI 10.1186/s12888-015-0389-x, PubMed 25651990

Lagerberg TV, Icick R, Andreassen OA, Ringen PA, Etain B, Aas M, Henry C, Bjella TD, Melle I, Bellivier F (2015)
Cannabis use disorder is associated with greater illness severity in tobacco smoking patients with bipolar disorder
J Affect Disord, 190, 286-293
DOI 10.1016/j.jad.2015.10.023, PubMed 26544611

Publications 2014

Kvitland LR, Melle I, Aminoff SR, Lagerberg TV, Andreassen OA, Ringen PA (2014)
Cannabis use in first-treatment bipolar I disorder: relations to clinical characteristics
Early Interv Psychiatry, 10 (1), 36-44
DOI 10.1111/eip.12138, PubMed 24739233

Ringen PA, Engh JA, Birkenaes AB, Dieset I, Andreassen OA (2014)
Increased mortality in schizophrenia due to cardiovascular disease - a non-systematic review of epidemiology, possible causes, and interventions
Front Psychiatry, 5, 137
DOI 10.3389/fpsyt.2014.00137, PubMed 25309466

Publications 2013

Lagerberg TV, Kvitland LR, Aminoff SR, Aas M, Ringen PA, Andreassen OA, Melle I (2013)
Indications of a dose-response relationship between cannabis use and age at onset in bipolar disorder
Psychiatry Res, 215 (1), 101-4
DOI 10.1016/j.psychres.2013.10.029, PubMed 24262665

Lange EH, Nesvåg R, Ringen PA, Hartberg CB, Haukvik UK, Andreassen OA, Melle I, Agartz I (2013)
One year follow-up of alcohol and illicit substance use in first-episode psychosis: does gender matter?
Compr Psychiatry, 55 (2), 274-82
DOI 10.1016/j.comppsych.2013.08.018, PubMed 24262129

Publications 2012

Beldie A, den Boer JA, Brain C, Constant E, Figueira ML, Filipcic I, Gillain B, Jakovljevic M, Jarema M, Jelenova D, Karamustafalioglu O, Kores Plesnicar B, Kovacsova A, Latalova K, Marksteiner J, Palha F, Pecenak J, Prasko J, Prelipceanu D, Ringen PA, Sartorius N, Seifritz E, Svestka J, Tyszkowska M, Wancata J (2012)
Fighting stigma of mental illness in midsize European countries
Soc Psychiatry Psychiatr Epidemiol, 47 Suppl 1, 1-38
DOI 10.1007/s00127-012-0491-z, PubMed 22526821

Jónsdóttir H, Opjordsmoen S, Birkenaes AB, Simonsen C, Engh JA, Ringen PA, Vaskinn A, Friis S, Sundet K, Andreassen OA (2012)
Predictors of medication adherence in patients with schizophrenia and bipolar disorder
Acta Psychiatr Scand, 127 (1), 23-33
DOI 10.1111/j.1600-0447.2012.01911.x, PubMed 22900964

Ringen PA, Melle I, Berg AO, Agartz I, Spigset O, Simonsen C, Sundet K, Andreassen OA (2012)
Cannabis use and premorbid functioning as predictors of poorer neurocognition in schizophrenia spectrum disorder
Schizophr Res, 143 (1), 84-9
DOI 10.1016/j.schres.2012.10.021, PubMed 23178107

Publications 2011

Lagerberg TV, Sundet K, Aminoff SR, Berg AO, Ringen PA, Andreassen OA, Melle I (2011)
Excessive cannabis use is associated with earlier age at onset in bipolar disorder
Eur Arch Psychiatry Clin Neurosci, 261 (6), 397-405
DOI 10.1007/s00406-011-0188-4, PubMed 21267743

Publications 2010

Jónsdóttir H, Opjordsmoen S, Birkenaes AB, Engh JA, Ringen PA, Vaskinn A, Aamo TO, Friis S, Andreassen OA (2010)
Medication adherence in outpatients with severe mental disorders: relation between self-reports and serum level
J Clin Psychopharmacol, 30 (2), 169-75
DOI 10.1097/JCP.0b013e3181d2191e, PubMed 20520290

Lagerberg TV, Andreassen OA, Ringen PA, Berg AO, Larsson S, Agartz I, Sundet K, Melle I (2010)
Excessive substance use in bipolar disorder is associated with impaired functioning rather than clinical characteristics, a descriptive study
BMC Psychiatry, 10, 9
DOI 10.1186/1471-244X-10-9, PubMed 20105311

Nesvåg R, Lange EH, Faerden A, Barrett EA, Emilsson B, Ringen PA, Andreassen OA, Melle I, Agartz I (2010)
The use of screening instruments for detecting alcohol and other drug use disorders in first-episode psychosis
Psychiatry Res, 177 (1-2), 228-34
DOI 10.1016/j.psychres.2010.01.007, PubMed 20178887

Publications 2009

Engh JA, Friis S, Birkenaes AB, Jónsdóttir H, Klungsøyr O, Ringen PA, Simonsen C, Vaskinn A, Opjordsmoen S, Andreassen OA (2009)
Delusions are associated with poor cognitive insight in schizophrenia
Schizophr Bull, 36 (4), 830-5
DOI 10.1093/schbul/sbn193, PubMed 19176474

Ringen PA, Vaskinn A, Sundet K, Engh JA, Jónsdóttir H, Simonsen C, Friis S, Opjordsmoen S, Melle I, Andreassen OA (2009)
Opposite relationships between cannabis use and neurocognitive functioning in bipolar disorder and schizophrenia
Psychol Med, 40 (8), 1337-47
DOI 10.1017/S0033291709991620, PubMed 19891810

Simonsen C, Sundet K, Vaskinn A, Birkenaes AB, Engh JA, Faerden A, Jónsdóttir H, Ringen PA, Opjordsmoen S, Melle I, Friis S, Andreassen OA (2009)
Neurocognitive dysfunction in bipolar and schizophrenia spectrum disorders depends on history of psychosis rather than diagnostic group
Schizophr Bull, 37 (1), 73-83
DOI 10.1093/schbul/sbp034, PubMed 19443616

Vaskinn A, Sundet K, Friis S, Ueland T, Simonsen C, Birkenaes AB, Engh JA, Jónsdóttir H, Opjordsmoen S, Ringen PA, Andreassen OA (2009)
Using the Wisconsin Card Sorting Test to assess learning potential in normal IQ schizophrenia: does it have potential?
Nord J Psychiatry, 63 (5), 405-11
DOI 10.1080/08039480902879941, PubMed 19365785

Publications 2008

Birkenaes AB, Birkeland KI, Engh JA, Faerden A, Jonsdottir H, Ringen PA, Friis S, Opjordsmoen S, Andreassen OA (2008)
Dyslipidemia independent of body mass in antipsychotic-treated patients under real-life conditions
J Clin Psychopharmacol, 28 (2), 132-7
DOI 10.1097/JCP.0b013e318166c4f7, PubMed 18344722

Jónsdóttir H, Engh JA, Friis S, Birkenaes A, Ringen PA, Vaskinn A, Sundet K, Opjordsmoen S, Andreassen OA (2008)
Measurement of insight in patients with bipolar disorder: are self-rated scales developed for patients with schizophrenia applicable?
J Nerv Ment Dis, 196 (4), 333-5
DOI 10.1097/NMD.0b013e31816a62b2, PubMed 18414129

Ringen PA (2008)
Psychoses and illicit drug use: need for cross-cultural studies - Reply
Acta Psychiatr. Scand., 118 (1), 86-87

Ringen PA, Melle I, Birkenaes AB, Engh JA, Faerden A, Vaskinn A, Friis S, Opjordsmoen S, Andreassen OA (2008)
The level of illicit drug use is related to symptoms and premorbid functioning in severe mental illness
Acta Psychiatr Scand, 118 (4), 297-304
DOI 10.1111/j.1600-0447.2008.01244.x, PubMed 18759810

Simonsen C, Sundet K, Vaskinn A, Birkenaes AB, Engh JA, Hansen CF, Jónsdóttir H, Ringen PA, Opjordsmoen S, Friis S, Andreassen OA (2008)
Neurocognitive profiles in bipolar I and bipolar II disorder: differences in pattern and magnitude of dysfunction
Bipolar Disord, 10 (2), 245-55
DOI 10.1111/j.1399-5618.2007.00492.x, PubMed 18271903

Vaskinn A, Sundet K, Friis S, Simonsen C, Birkenaes AB, Jónsdóttir H, Ringen PA, Andreassen OA (2008)
Emotion perception and learning potential: mediators between neurocognition and social problem-solving in schizophrenia?
J Int Neuropsychol Soc, 14 (2), 279-88
DOI 10.1017/S1355617708080314, PubMed 18282325

Publications 2007

Birkenaes AB, Opjordsmoen S, Brunborg C, Engh JA, Jonsdottir H, Ringen PA, Simonsen C, Vaskinn A, Birkeland KI, Friis S, Sundet K, Andreassen OA (2007)
The level of cardiovascular risk factors in bipolar disorder equals that of schizophrenia: a comparative study
J Clin Psychiatry, 68 (6), 917-23
DOI 10.4088/JCP.v68n0614, PubMed 17592917

Engh JA, Friis S, Birkenaes AB, Jónsdóttir H, Ringen PA, Ruud T, Sundet KS, Opjordsmoen S, Andreassen OA (2007)
Measuring cognitive insight in schizophrenia and bipolar disorder: a comparative study
BMC Psychiatry, 7, 71
DOI 10.1186/1471-244X-7-71, PubMed 18072961

Ringen PA (2007)
[Medicine and psychiatry--in part and divided?]
Tidsskr Nor Laegeforen, 127 (7), 908-10
PubMed 17435816

Ringen PA, Lagerberg TV, Birkenaes AB, Engn J, Faerden A, Jónsdottir H, Nesvåg R, Friis S, Opjordsmoen S, Larsen F, Melle I, Andreassen OA (2007)
Differences in prevalence and patterns of substance use in schizophrenia and bipolar disorder
Psychol Med, 38 (9), 1241-9
DOI 10.1017/S003329170700236X, PubMed 18070373

Ringen PA, Melle I, Birkenaes AB, Engh JA, Faerden A, Jónsdóttir H, Nesvåg R, Vaskinn A, Friis S, Larsen F, Opjordsmoen S, Sundet K, Andreassen OA (2007)
Illicit drug use in patients with psychotic disorders compared with that in the general population: a cross-sectional study
Acta Psychiatr Scand, 117 (2), 133-8
DOI 10.1111/j.1600-0447.2007.01135.x, PubMed 18081921

Vaskinn A, Sundet K, Friis S, Simonsen C, Birkenaes AB, Engh JA, Jónsdóttir H, Ringen PA, Opjordsmoen S, Andreassen OA (2007)
The effect of gender on emotion perception in schizophrenia and bipolar disorder
Acta Psychiatr Scand, 116 (4), 263-70
DOI 10.1111/j.1600-0447.2007.00991.x, PubMed 17803756

Publications 2006

Birkenaes AB, Søgaard AJ, Engh JA, Jonsdottir H, Ringen PA, Vaskinn A, Friis S, Sundet K, Opjordsmoen S, Andreassen OA (2006)
Sociodemographic characteristics and cardiovascular risk factors in patients with severe mental disorders compared with the general population
J Clin Psychiatry, 67 (3), 425-33
DOI 10.4088/JCP.v67n0314, PubMed 16649830

Publications 2002

Ringen PA, Dahl AA (2002)
[Models and trends in psychiatry--should neurobiology form a common basis?]
Tidsskr Nor Laegeforen, 122 (20), 2024-7
PubMed 12555451

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