• Anti-depressive effectiveness of olanzapine, quetiapine, risperidone and ziprasidone: a pragmatic, randomized trial 

      Kjelby, Eirik; Jørgensen, Hugo A.; Kroken, Rune A.; Løberg, Else-Marie; Johnsen, Erik (Peer reviewed; Journal article, 2011-08-31)
      Background: Efficacy studies indicate anti-depressive effects of at least some second generation antipsychotics (SGAs). The Bergen Psychosis Project (BPP) is a 24-month, pragmatic, industry-independent, randomized, head-tohead ...
    • The association between cytokines and psychomotor speed in a spectrum of psychotic disorders: A longitudinal study 

      Larsen, Jeanette Brun; Reitan, Solveig Merete Klæbo; Løberg, Else-Marie; Rettenbacher, Maria; Bruserud, Øystein; Larsen, Tor Ketil; Anda, Liss Gøril; Bartz-Johannessen, Christoffer; Johnsen, Erik; Kroken, Rune Andreas (Journal article, 2021)
      Background In schizophrenia, impaired psychomotor speed is a common symptom predicting worse functional outcome. Inflammation causes changes in white matter integrity, which may lead to reduced psychomotor speed. Therefore, ...
    • Brain age prediction reveals aberrant brain white matter in schizophrenia and bipolar disorder: A multi-sample diffusion tensor imaging study 

      Tønnesen, Siren; Kaufmann, Tobias; de Lange, Ann-Marie Glasø; Richard, Geneviève; Nhat Trung, Doan; Alnæs, Dag; van der Meer, Dennis; Rokicki, Jaroslav; Moberget, Torgeir; Maximov, Ivan; Agartz, Ingrid; Aminoff, Sofie Ragnhild; Beck, Dani; Barch, Deanna M.; Beresniewicz, Justyna; Cervenka, Simon; Fatouros-Bergman, Helena; Craven, Alexander R.; Flyckt, Lena; Gurholt, Tiril Pedersen; Haukvik, Unn Kristin H.; Hugdahl, Kenneth; Johnsen, Erik; Jönsson, Erik Gunnar; Schizophrenia Project (KaSP), Karolinska; Kolskår, Knut-Kristian; Kroken, Rune Andreas; Lagerberg, Trine Vik; Løberg, Else-Marie; Nordvik, Jan Egil; Sanders, Anne-Marthe; Ulrichsen, Kristine Moe; Andreassen, Ole Andreas; Westlye, Lars Tjelta (Journal article; Peer reviewed, 2020)
      Background Schizophrenia (SZ) and bipolar disorder (BD) share substantial neurodevelopmental components affecting brain maturation and architecture. This necessitates a dynamic lifespan perspective in which brain aberrations ...
    • The cannabis pathway to non-affective psychosis may reflect less neurobiological vulnerability 

      Løberg, Else-Marie; Helle, Siri; Nygård, Merethe; Berle, Jan Øystein; Kroken, Rune; Johnsen, Erik (Peer reviewed; Journal article, 2014-11-18)
      There is a high prevalence of cannabis use reported in non-affective psychosis. Early prospective longitudinal studies conclude that cannabis use is a risk factor for psychosis, and neurochemical studies on cannabis have ...
    • Cognitive change and antipsychotic medications: Results from a pragmatic rater-blind RCT 

      Anda, Liss; Johnsen, Erik; Kroken, Rune A.; Joa, Inge; Rettenbacher, Maria; Løberg, Else-Marie (Journal article; Peer reviewed, 2021)
      Cognitive impairment is a core aspect of psychotic disorders and difficult to treat. Atypical antipsychotics (AAs) might have differential effects on cognitive impairment, but rigid study designs and selective sampling ...
    • Cognitive changes in patients with acute phase psychosis - Effects of illicit drug use 

      Helle, Siri; Gjestad, Rolf; Johnsen, Erik; Kroken, Rune; Jørgensen, Hugo A.; Løberg, Else-Marie (Peer reviewed; Journal article, 2014-12)
      Illicit drug use may influence cognition in non-affective psychosis. Previous studies have shown better cognition in psychosis with illicit drug use as compared to psychosis only. Possibly, illicit drug using patients have ...
    • Cognitive profile in ultra high risk for psychosis and schizophrenia: A comparison using coordinated norms 

      Anda-Ågotnes, Liss Gøril; Brønnick, Kolbjørn Kallesten; Johannessen, Jan Olav; Joa, Inge; Kroken, Rune Andreas; Johnsen, Erik; Rettenbacher, Maria; Fathian, Farivar; Løberg, Else-Marie (Peer reviewed; Journal article, 2019-10-01)
      Background: Cognitive impairment is not only a core aspect of schizophrenia but also commonly observed in help-seeking youth at ultra high risk for psychosis (UHR), with potential implications for prognosis and individualized ...
    • Constructing the immune signature of schizophrenia for clinical use and research; an integrative review translating descriptives into diagnostics 

      Kroken, Rune Andreas; Sommer, Iris Else Clara; Steen, Vidar Martin; Dieset, Ingrid; Johnsen, Erik (Peer reviewed; Journal article, 2019)
      Schizophrenia is considered a syndrome comprised by several disease phenotypes, covering a range of underlying pathologies. One of these disease mechanisms seems to involve immune dysregulation and neuroinflammation. While ...
    • A critical review of pro-cognitive drug targets in psychosis: convergence on myelination and inflammation 

      Kroken, Rune; Løberg, Else-Marie; Drønen, Tore; Grüner, Renate; Hugdahl, Kenneth; Kompus, Kristiina; Skrede, Silje; Johnsen, Erik (Peer reviewed; Journal article, 2014-02-04)
      Antipsychotic drugs have thus far focused on dopaminergic antagonism at the D2 receptors, as counteracting the hyperdopaminergia in nigrostriatal and mesolimbic projections has been considered mandatory for the antipsychotic ...
    • Differential Effectiveness of Atypical Antipsychotics on Hallucinations: A Pragmatic Randomized Controlled Trial 

      Sinkeviciute, Igne; Hugdahl, Kenneth Jan; Bartz-Johannessen, Christoffer; Kroken, Rune Andreas; Løberg, Else-Marie; Kjelby, Eirik; Rettenbacher, maria; Joa, Inge; Reitan, Solveig Merete Klæbo; Alisauskiene, Renata; Fathian, Farivar; Johnsen, Erik (Journal article; Peer reviewed, 2021-07)
      Background Most studies investigating antipsychotic effectiveness report either total psychopathology or symptom cluster findings. Studies focusing on a separate symptom, such as hallucinations, a hallmark symptom in ...
    • Does childhood trauma influence cognitive functioning in schizophrenia? The association of childhood trauma and cognition in schizophrenia spectrum disorders. 

      Mørkved, Nina; Johnsen, Erik; Kroken, Rune Andreas; Gjestad, Rolf; Winje, Dagfinn; Thimm, J.; Fathian, Farivar; Rettenbacher, Maria; Anda-Ågotnes, Liss Gøril; Løberg, Else-Marie (Journal article; Peer reviewed, 2020)
      Childhood trauma (CT) is a risk factor for schizophrenia spectrum disorders (SSDs), and cognitive impairment is a core feature and a vulnerability marker of SSDs. Studies of the relationship between CT and cognitive ...
    • Dynamic Functional Connectivity Patterns in Schizophrenia and the Relationship With Hallucinations 

      Weber, Sarah; Johnsen, Erik; Kroken, Rune Andreas; Løberg, Else-Marie; Kandilarova, Sevdalina; Stoyanov, Drozdstoy; Kompus, Kristiina; Hugdahl, Kenneth (Journal article; Peer reviewed, 2020)
      There is a wealth of evidence showing aberrant functional connectivity (FC) in schizophrenia but with considerable variability in findings across studies. Dynamic FC is an extension of traditional static FC, in that such ...
    • Effectiveness of second generation antipsychotics: A systematic review of randomized trials 

      Johnsen, Erik; Jørgensen, Hugo A. (Peer reviewed; Journal article, 2008-04-25)
      Background Systematic reviews based on efficacy trials are inconclusive about which second generation antipsychotic drug (SGA) should be preferred in normal clinical practice, and studies with longer duration and more ...
    • Effectiveness of second-generation antipsychotics: a naturalistic, randomized comparison of olanzapine, quetiapine, risperidone, and ziprasidone 

      Johnsen, Erik; Kroken, Rune A.; Wentzel-Larsen, Tore; Jørgensen, Hugo A. (Peer reviewed; Journal article, 2010-03-24)
      Background: No clear recommendations exist regarding which antipsychotic drug should be prescribed first for a patient suffering from psychosis. The primary aims of this naturalistic study were to assess the head-to-head ...
    • Efficacy of different types of cognitive enhancers for patients with schizophrenia: a meta-analysis 

      Sinkeviciute, Igne; Begemann, Marieke; Prikken, Merel; Oranje, Bob; Johnsen, Erik; Lei, Wan U.; Hugdahl, Kenneth; Kroken, Rune Andreas; Rau, Carina; Jacobs, Jolien D.; Mattaroccia, Silvia; Sommer, Iris Else Clara (Peer reviewed; Journal article, 2018)
      Cognitive impairment is a core feature of schizophrenia, which is predictive for functional outcomes and is, therefore, a treatment target in itself. Yet, literature on efficacy of different pharmaco-therapeutic options ...
    • Elderly Patients With No Previous Psychiatric History: Suicidality and Other Factors Relating to Psychiatric Acute Admissions 

      Lund-Heimark, Hallvard; Kjelby, Eirik; Mehlum, Lars; Gjestad, Rolf; Selbæk, Geir; Kroken, Rune Andreas; Johnsen, Erik; Ødegaard, Ketil Joachim; Mellesdal, Liv Solrunn (Journal article; Peer reviewed, 2020)
      Background: The common recommendation that adults with onset of mental illness after the age of 65 should receive specialised psychogeriatric treatment is based on limited evidence. Aims: To compare factors related to ...
    • Glutamate- and GABA-Modulated Connectivity in Auditory Hallucinations—A Combined Resting State fMRI and MR Spectroscopy Study 

      Weber, Sarah; Hjelmervik, Helene; Craig-Craven, Alexander Richard; Johnsen, Erik; Kroken, Rune Andreas; Løberg, Else-Marie; Ersland, Lars; Kompus, Kristiina; Hugdahl, Kenneth (Journal article; Peer reviewed, 2021)
      Background: Auditory verbal hallucinations (AVH) have been linked to aberrant interhemispheric connectivity between the left and the right superior temporal gyrus (STG), labeled the interhemispheric miscommunication theory. ...
    • Hallucinating schizophrenia patients have longer left arcuate fasciculus fiber tracks: a DTI tractography study 

      Falkenberg, Liv E.; Westerhausen, René; Johnsen, Erik; Kroken, Rune Andreas; Løberg, Else-Marie; Beresniewicz, Justyna; Kazimierczak, Katarzyna Anna; Kompus, Kristiina; Ersland, Lars; Sandøy, Lydia Brunvoll; Hugdahl, Kenneth (Journal article; Peer reviewed, 2020)
      The arcuate fasciculus (AF) has been implicated in the pathology behind schizophrenia and auditory verbal hallucinations (AVHs). White matter tracts forming the arcuate fasciculus can be quantified and visualized using ...
    • Hallucinations in acutely admitted patients with psychosis, and effectiveness of risperidone, olanzapine, quetiapine, and ziprasidone: a pragmatic, randomized study 

      Johnsen, Erik; Sinkeviciute, Igne; Løberg, Else-Marie; Kroken, Rune A.; Hugdahl, Kenneth; Jørgensen, Hugo A. (Peer reviewed; Journal article, 2013-09-30)
      Background Hallucinations are prevalent in schizophrenia and related psychotic disorders and may have severe consequences for the affected patients. Antipsychotic drug trials that specifically address the anti-hallucinatory ...
    • Increased circulating IL-18 levels in severe mental disorders indicate systemic inflammasome activation 

      Szabo, Attila; O'Connell, Kevin Sean; Ueland, Thor; Sheikh, Mashhood Ahmed; Agartz, Ingrid; Andreou, Dimitrios; Aukrust, Pål; Boye, Birgitte; Bøen, Erlend; Drange, Ole Kristian; Elvsåshagen, Torbjørn; Engh, John; Hope, Sigrun; Høegh, Margrethe Collier; Joa, Inge; Johnsen, Erik; Kroken, Rune Andreas; Lagerberg, Trine Vik; Lekva, Tove; Malt, Ulrik Fredrik; Melle, Ingrid; Morken, Gunnar; Nærland, Terje; Steen, Vidar Martin; Sørensen, Kjetil; Wedervang-Resell, Kirsten; Weibell, Melissa Anne Elin Authen; Westlye, Lars Tjelta; Steen, Nils Eiel; Andreassen, Ole; Djurovic, Srdjan (Journal article; Peer reviewed, 2022)
      Background Schizophrenia (SCZ) and bipolar disorder (BD) are severe mental illnesses (SMI) that are part of a psychosis continuum, and dysregulated innate immune responses have been suggested to be involved in their ...