Blar i Bergen Open Research Archive på forfatter "Johnsen, Erik"
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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 ... -
GABA, glutamatergic dynamics and BOLD contrast assessed concurrently using functional MRS during a cognitive task
Craven, Alexander R.; Dwyer, Gerard Eric; Ersland, Lars; Kazimierczak, Katarzyna Anna; Noeske, Ralph; Sandøy, Lydia Brunvoll; Johnsen, Erik; Hugdahl, Kenneth Jan (Journal article; Peer reviewed, 2023)A recurring issue in functional neuroimaging is how to link task-driven haemodynamic blood oxygen level dependent functional MRI (BOLD-fMRI) responses to underlying neurochemistry at the synaptic level. Glutamate and ... -
Glutamate- and GABA-Modulated Connectivity in Auditory Hallucinations—A Combined Resting State fMRI and MR Spectroscopy Study
Weber, Sarah; Hjelmervik, Helene; Craven, Alexander R.; 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 ... -
Illicit substances detected through high-resolution MS analysis in urine samples are associated with greater symptom burden in patients with psychosis
Skrede, Silje; Berg, Jon Andsnes; Fossan, Kjell Ove; Bartz-Johannessen, Christoffer; Løberg, Else-Marie; Kroken, Rune Andreas; Johnsen, Erik (Journal article, 2021)Background The prevalence of new psychoactive substances (NPS) in acute psychotic patients has not been investigated systematically. We applied a highly sensitive and specific mass spectrometry method for detection of NPS ... -
Impact of childhood trauma on antipsychotic effectiveness in schizophrenia spectrum disorders: A prospective, pragmatic, semi-randomized trial
Mørkved, Nina; Johnsen, Erik; Kroken, Rune Andreas; Winje, Dagfinn; Larsen, Tor Ketil; Thimm, Jens; Rettenbacher, M.A.; Johannesen, C.A. Bartz; Løberg, Else-Marie (Journal article; Peer reviewed, 2022)Antipsychotic medications are generally effective in ameliorating psychotic symptoms in schizophrenia spectrum disorders (SSDs). Identifying predictors associated with poor treatment response is important for a personalized ... -
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 ... -
Intra-Regional Glu-GABA vs Inter-Regional Glu-Glu Imbalance: A 1H-MRS Study of the Neurochemistry of Auditory Verbal Hallucinations in Schizophrenia.
Hjelmervik, Helene; Craven, Alexander R.; Sinkeviciute, Igne; Johnsen, Erik; Kompus, Kristiina; Bless, Josef Johann; Kroken, Rune Andreas; Løberg, Else-Marie; Ersland, Lars; Gruner, Eli Renate; Hugdahl, Kenneth (Peer reviewed; Journal article, 2019-10-18)Glutamate (Glu), gamma amino-butyric acid (GABA), and excitatory/inhibitory (E/I) imbalance have inconsistently been implicated in the etiology of schizophrenia. Elevated Glu levels in language regions have been suggested ... -
Long term outcomes and causal modelling of compulsory inpatient and outpatient mental health care using Norwegian registry data : protocol for a controversies in psychiatry research project
Hofstad, Tore; Nyttingnes, Olav; Markussen, Simen; Johnsen, Erik; Killackey, Eoin; McDaid, David; Rinaldi, Miles; Dean, Kimberlie; Brinchmann, Beate; Douglas, Kevin Stewart; Gröning, Linda; Bjørkly, Stål Kapstø; Palmstierna, Tom Krisman Kule; Strømme, Maria Fagerbakke; Blindheim, Anne Alnes; Rugkåsa, Jorun; Hofmann, Bjørn Morten; Pedersen, Reidar; Widding-Havnerås, Tarjei; Rypdal, Knut; Mykletun, Arnstein (Journal article; Peer reviewed, 2023)Objectives: Compulsory mental health care includes compulsory hospitalisation and outpatient commitment with medication treatment without consent. Uncertain evidence of the effects of compulsory care contributes to large ... -
Lower circulating neuron-specific enolase concentrations in adults and adolescents with severe mental illness
Andreou, Dimitrios; Steen, Nils Eiel; Jørgensen, Kjetil Nordbø; Smelror, Runar Elle; Wedervang-Resell, Kirsten; Nerland, Stener; Westlye, Lars Tjelta; Nærland, Terje; Myhre, Anne Margrethe; Joa, Inge; Reitan, Solveig Merete Klæbo; Vaaler, Arne; Morken, Gunnar; Bøen, Erlend; Elvsåshagen, Torbjørn; Boye, Birgitte; Malt, Ulrik Fredrik; Aukrust, Pål; Skrede, Silje; Kroken, Rune Andreas; Johnsen, Erik; Djurovic, Srdjan; Andreassen, Ole; Ueland, Thor; Agartz, Ingrid (Journal article; Peer reviewed, 2021)Background: Both neurodegenerative and neurodevelopmental abnormalities have been suggested to be part of the etiopathology of severe mental illness (SMI). Neuron-specific enolase (NSE), mainly located in the neuronal ... -
Mapping psychotic-like experiences: Results from an online survey
Kusztrits, Isabella; Larøi, Frank; Laloyaux, Julien Freddy; Marquardt, Lynn Anne; Sinkeviciute, Igne; Kjelby, Eirik; Johnsen, Erik; Sommer, Iris Else Clara; Hugdahl, Kenneth; Hirnstein, Marco (Journal article; Peer reviewed, 2021)Suggestions have been made that psychotic‐like experiences (PLEs), such as hallucinatory and delusional experiences, exist on a continuum from healthy individuals to patients with a diagnosis of schizophrenia. We used the ... -
Mortality and non-use of antipsychotic drugs after acute admission in schizophrenia: A prospective total-cohort study
Strømme, Maria Fagerbakke; Mellesdal, Liv Solrunn; Bartz-Johannesen, Christoffer; Kroken, Rune Andreas; Krogenes, Marianne; Mehlum, Lars; Johnsen, Erik (Journal article; Peer reviewed, 2021)Background: In society at large, it is debated whether use of antipsychotic drugs is associated with increased or decreased mortality among patients with schizophrenia. Large register studies have demonstrated an increased ... -
Negative valence of hallucinatory voices as predictor of cortical glutamatergic metabolite levels in schizophrenia patients
Hjelmervik, Helene; Craven, Alexander R.; Johnsen, Erik; Kompus, Kristiina; Bless, Josef Johann; Sinkeviciute, Igne; Kroken, Rune Andreas; Løberg, Else-Marie; Ersland, Lars; Grüner, Eli Renate; Sommer, Iris E.; Hugdahl, Kenneth Jan (Journal article; Peer reviewed, 2021)Objectives Negative emotional valence of auditory verbal hallucinations (AVHs) in schizophrenia can be a source of distress and is considered a strong predictor of illness severity. Previous studies have found glutamate ... -
Neural activation in the ventromedial prefrontal cortex precedes conscious experience of being in or out of a transient hallucinatory state
Hugdahl, Kenneth; Craven, Alexander R.; Johnsen, Erik; Ersland, Lars; Stoyanov, Drozdstoy; Kandilarova, Sevdalina; Sandøy, Lydia Brunvoll; Kroken, Rune A.; Løberg, Else-Marie; Sommer, Iris E. (Journal article; Peer reviewed, 2022)Background and Hypotheses Auditory verbal hallucinations (AVHs) is not only a common symptom in schizophrenia but also observed in individuals in the general population. Despite extensive research, AVHs are poorly understood, ... -
One-year outcome and adherence to pharmacological guidelines in first-episode schizophrenia: Results from a consecutive cohort study
Drosos, Petros; Brønnick, Kolbjørn Kallesten; Joa, Inge; Johannessen, Jan Olav; Johnsen, Erik; Kroken, Rune Andreas; Stain, Helen J.; Hegelstad, Wenche; Larsen, Tor Ketil (Journal article; Peer reviewed, 2020)Background Remission in schizophrenia is difficult to achieve. Antipsychotic drugs are critical in the treatment of schizophrenia. International guidelines for the pharmacological treatment of schizophrenia recommend a ... -
Overactive, aggressive, disruptive and agitated behavior associated with the use of psychotropic medications in schizophrenia
Strømme, Maria Fagerbakke; Bartz-Johannessen, Christoffer; Kroken, Rune Andreas; Mehlum, Lars; Johnsen, Erik (Journal article; Peer reviewed, 2022)Background: Evidence is limited for the associations between use of psychotropic medications and overactive, aggressive, disruptive or agitated behavior (OADA)1 in clinical practice. Aims: To investigate the associations ...