Erik Johnsen's picture

Erik Johnsen

  • E-mailErik.Johnsen@uib.no
  • Visitor Address
    Haukeland Universitetssykehus Laboratoriebygget, 7. etg. Heis øst
    5009 Bergen
  • Postal Address
    Postboks 7804
    5020 Bergen
Academic article
  • Show author(s) (2022). Use of Benzodiazepines and Antipsychotic Drugs Are Inversely Associated with Acute Readmission Risk in Schizophrenia. Journal of Clinical Psychopharmacology. 37-42.
  • Show author(s) (2022). Quality of clinical management of cardiometabolic risk factors in patients with severe mental illness in a specialist mental health care setting. Nordic Journal of Psychiatry. 1-8.
  • Show author(s) (2022). Neural activation in the ventromedial prefrontal cortex precedes conscious experience of being in or out of a transient hallucinatory state. Schizophrenia Bulletin.
  • Show author(s) (2022). Association between C-reactive protein levels and antipsychotic treatment during 12 months follow-up period after acute psychosis. Schizophrenia Research. 174-183.
  • Show author(s) (2022). Akathisia and atypical antipsychotics. Relation to suicidality, agitation and depression in a clinical trial. Acta Neuropsychiatrica. 1-7.
  • Show author(s) (2021). White matter microstructural differences between hallucinating and non-hallucinating schizophrenia spectrum patients. Diagnostics (Basel). 1-14.
  • Show author(s) (2021). The association between cytokines and psychomotor speed in a spectrum of psychotic disorders: A longitudinal study. Brain, Behavior, & Immunity - Health. 100392.
  • Show author(s) (2021). The Influence of Substance Use on Side Effects of Olanzapine, Quetiapine, Risperidone, and Ziprasidone in Psychosis. Substance Use & Misuse. 1880-1891.
  • Show author(s) (2021). Sex differences in antipsychotic efficacy and side effects in schizophrenia spectrum disorder: results from the BeSt InTro study. Nature NPJ Schizophrenia. 1-7.
  • Show author(s) (2021). Plasma Levels of the Cytokines B Cell-Activating Factor (BAFF) and A Proliferation-Inducing Ligand (APRIL) in Schizophrenia, Bipolar, and Major Depressive Disorder: A Cross Sectional, Multisite Study. Schizophrenia Bulletin. 1-10.
  • Show author(s) (2021). Negative valence of hallucinatory voices as predictor of cortical glutamatergic metabolite levels in schizophrenia patients. Brain and Behavior.
  • Show author(s) (2021). Mortality and non-use of antipsychotic drugs after acute admission in schizophrenia: A prospective total-cohort study. Schizophrenia Research. 29-35.
  • Show author(s) (2021). Lower circulating neuron-specific enolase concentrations in adults and adolescents with severe mental illness. Psychological Medicine. 1-10.
  • Show author(s) (2021). Increased circulating IL-18 levels in severe mental disorders indicate systemic inflammasome activation. Brain, Behavior, and Immunity. 299-306.
  • Show author(s) (2021). Illicit substances detected through high-resolution MS analysis in urine samples are associated with greater symptom burden in patients with psychosis. Emerging Trends in Drugs, Addictions, and Health.
  • Show author(s) (2021). Glutamate- and GABA-Modulated Connectivity in Auditory Hallucinations—A Combined Resting State fMRI and MR Spectroscopy Study. Frontiers in Psychiatry. 1-10.
  • Show author(s) (2021). Differential Effectiveness of Atypical Antipsychotics on Hallucinations: A Pragmatic Randomized Controlled Trial. Journal of Clinical Psychopharmacology. 389-396.
  • Show author(s) (2021). Cognitive change and antipsychotic medications: Results from a pragmatic rater-blind RCT. Schizophrenia Research: Cognition. 1-8.
  • Show author(s) (2020). Prednisolone versus placebo addition in the treatment of patients with recent-onset psychotic disorder: A trial design. Trials. 1-13.
  • Show author(s) (2020). One-year outcome and adherence to pharmacological guidelines in first-episode schizophrenia: Results from a consecutive cohort study. Journal of Clinical Psychopharmacology. 534-540.
  • Show author(s) (2020). Mapping psychotic-like experiences: Results from an online survey. Scandinavian Journal of Psychology. 1-12.
  • Show author(s) (2020). Hallucinating schizophrenia patients have longer left arcuate fasciculus fiber tracks: a DTI tractography study. Psychiatry Research : Neuroimaging. 1-7.
  • Show author(s) (2020). Elderly Patients With No Previous Psychiatric History: Suicidality and Other Factors Relating to Psychiatric Acute Admissions . BJPsych Open.
  • Show author(s) (2020). Dynamic functional connectivity patterns in schizophrenia and the relationship with hallucinations. Frontiers in Psychiatry. 1-9.
  • Show author(s) (2020). Does childhood trauma influence cognitive functioning in schizophrenia? The association of childhood trauma and cognition in schizophrenia spectrum disorders. Schizophrenia Research: Cognition. 1-8.
  • Show author(s) (2020). Different response patterns in hallucinations and delusions to antipsychotic treatment. Nordic Journal of Psychiatry. 497-504.
  • Show author(s) (2020). Brain age prediction reveals aberrant brain white matter in schizophrenia and bipolar disorder: A multisample diffusion tensor imaging study. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. 1095-1103.
  • Show author(s) (2020). Amisulpride, aripiprazole, and olanzapine in patients with schizophrenia-spectrum disorders (BeSt InTro): a pragmatic, rater-blind, semi-randomised trial. The Lancet Psychiatry. 945-954.
  • Show author(s) (2019). Trends in utilization and dosing of antipsychotic drugs in Scandinavia: Comparison of 2006 and 2016. British Journal of Clinical Pharmacology. 1598-1606.
  • Show author(s) (2019). The influence of substance use on the effectiveness of antipsychotic medication: a prospective, pragmatic study. Nordic Journal of Psychiatry. 281-287.
  • Show author(s) (2019). Supported accommodation for people with schizophrenia. Nordic Journal of Psychiatry. 211-218.
  • Show author(s) (2019). Predictors of treatment satisfaction in antipsychotic-naive and previously medicated patients with acute-phase psychosis. Nordic Journal of Psychiatry. 349-356.
  • Show author(s) (2019). Intra-Regional Glu-GABA vs Inter-Regional Glu-Glu Imbalance: A 1H-MRS Study of the Neurochemistry of Auditory Verbal Hallucinations in Schizophrenia. Schizophrenia Bulletin.
  • Show author(s) (2019). Cognitive profile in ultra high risk for psychosis and schizophrenia: A comparison using coordinated norms. Frontiers in Psychiatry. 1-11.
  • Show author(s) (2018). Trajectories of depressive symptoms in the acute phase of psychosis: Implications for treatment. Journal of Psychiatric Research. 219-228.
  • Show author(s) (2018). Efficacy of different types of cognitive enhancers for patients with schizophrenia: a meta-analysis. Nature NPJ Schizophrenia. 1-14.
  • Show author(s) (2018). Childhood trauma in schizophrenia spectrum disorders as compared to substance abuse disorders. Psychiatry Research. 481-487.
  • Show author(s) (2018). Associations between C-reactive protein levels and cognition during the first 6 months after acute psychosis. Acta Neuropsychiatrica. 1-10.
  • Show author(s) (2017). The Beliefs about Voices Questionnaire - Revised: A factor structure from 450 participants. Psychiatry Research. 95-103.
  • Show author(s) (2016). The serum level of C-reactive protein (CRP) is associated with cognitive performance in acute phase psychosis. BMC Psychiatry.
  • Show author(s) (2016). The course of neurocognitive changes in acute psychosis: Relation to symptomatic improvement. PLOS ONE. 13 pages.
  • Show author(s) (2016). Patient satisfaction after acute admission for psychosis. Nordic Journal of Psychiatry. 321-328.
  • Show author(s) (2016). Influence of different second generation antipsychotics on the QTC interval: A pragmatic study. World Journal of Psychiatry (WJP). 442-448.
  • Show author(s) (2016). Childhood trauma in schizophrenia spectrum disorder as compared to other mental health disorders. Psychosis. 48-56.
  • Show author(s) (2016). Cannabis use is associated with 3 years earlier onset of schizophrenia spectrum disorder in a naturalistic, multi-site sample (N = 1119). Schizophrenia Research. 217-221.
  • Show author(s) (2015). Suicidality in schizophrenia spectrum disorders: The relationship to hallucinations and persecutory delusions. European psychiatry. 830-836.
  • Show author(s) (2015). Glutamate as a mediating transmitter for auditory hallucinations in schizophrenia: A 1H MRS study. . Schizophrenia Research. 252-260.
  • Show author(s) (2015). Borderline personality disorder and posttraumatic stress disorder at psychiatric discharge predict general hospital admission for self-harm. Journal of Traumatic Stress. 556-562.
  • Show author(s) (2015). Auditory verbal hallucinations reflect stable auditory attention deficits: A prospective study. Cognitive Neuropsychiatry. 81-94.
  • Show author(s) (2014). Time to discontinuation of antipsychotic drugs in a schizophrenia cohort: influence of current treatment strategies. Therapeutic Advances in Psychopharmacology. 228-239.
  • Show author(s) (2014). Impact of glutamate levels on neuronal response and cognitive abilities in schizophrenia. NeuroImage: Clinical. 576-584.
  • Show author(s) (2014). Failure of attention focus and cognitive control in schizophrenia patients with auditory verbal hallucinations: Evidence from dichotic listening. Schizophrenia Research. 301-309.
  • Show author(s) (2014). Do auditory verbal hallucinations in the acute phase of psychosis reflect stable cognitive impairments seen also in a more stabilised clinical phase? Cognitive Neuropsychiatry. 81-94.
  • Show author(s) (2014). Cognitive changes in patients with acute phase psychosis - Effects of illicit drug use. Psychiatry Research. 818-824.
  • Show author(s) (2013). The role of the primary auditory cortex in the neural mechanism of auditory verbal hallucinations. Frontiers in Human Neuroscience. 13 pages.
  • Show author(s) (2013). The influence of glutamatergic antagonism on motor variability, and comparison to findings in schizophrenia patients. Acta Neuropsychiatrica. 105-112.
  • Show author(s) (2013). QTc prolongation in patients acutely admitted to hospital for psychosis and treated with second generation antipsychotics. Schizophrenia Research and Treatment.
  • Show author(s) (2013). Prospective and concurrent correlates of emotion perception in psychotic disorders: a naturalistic, longitudinal study of neurocognition. Scandinavian Journal of Psychology. 261-266.
  • Show author(s) (2013). Neurocognitive effectiveness of quetiapine, olanzapine, risperidone, and ziprasidone: A pragmatic, randomized trial. European psychiatry. 174-184.
  • Show author(s) (2013). Hallucinations in acutely admitted patients with psychosis, and effectiveness of risperidone, olanzapine, quetiapine, and ziprasidone: a pragmatic, randomized study. BMC Psychiatry.
  • Show author(s) (2013). Dichotic listening, executive functions and grey matter cortical volume in patients with schizophrenia and healthy controls. Scandinavian Journal of Psychology. 443-450.
  • Show author(s) (2012). Time-dependent effect analysis of antipsychotic treatment in a naturalistic cohort study of patients with schizophrenia. European psychiatry. 489-495.
  • Show author(s) (2012). Priapism in antipsychotic drug use: a rare but important side effect. Case Reports in Psychiatry. 496364.
  • Show author(s) (2012). Patients with schizophrenia fail to up-regulate task-positive and down-regulate task-negative brain networks: An fMRI study using an ICA analysis approach. Frontiers in Human Neuroscience.
  • Show author(s) (2012). Auditory verbal hallucinations in schizophrenia as aberrant lateralized speech perception: Evidence from dichotic listening. Schizophrenia Research. 59-64.
  • Show author(s) (2012). An fMRI study of neuronal activation in schizophrenia patients with and without previous cannabis use. Frontiers in Human Neuroscience.
  • Show author(s) (2011). Sexual dysfunction and hyperprolactinemia in male psychotic in-patients: a cross-sectional study. Advances in Urology. 686924.
  • Show author(s) (2011). Neurocognitive effectiveness of quetiapine, olanzapine, risperidone, and ziprasidone: a pragmatic, randomized trial. European psychiatry.
  • Show author(s) (2011). Cardiovascular risk in patients admitted for psychosis compared with findings from a population-based study. Nordic Journal of Psychiatry. 192-202.
  • Show author(s) (2011). Anti-depressive effectiveness of olanzapine, quetiapine, risperidone and ziprasidone: a pragmatic, randomized trial. BMC Psychiatry. 10 pages.
  • Show author(s) (2010). Effectiveness of second-generation antipsychotics: a naturalistic, randomized comparison of olanzapine, quetiapine, risperidone, and ziprasidone. BMC Psychiatry. 13 pages.
  • Show author(s) (2009). Treatment of schizophrenia with antipsychotics in Norwegian emergency wards, a cross-sectional national study. BMC Psychiatry. 9 pages.
  • Show author(s) (2008). Antipsychotic-induced hyperprolactinemia: A cross-sectional survey. Journal of Clinical Psychopharmacology. 686-690.
  • Show author(s) (2006). Antipsykotikaindusert hyperprolaktinemi. Tidsskrift for Den norske legeforening. 179-180.
  • Show author(s) (2004). Practice regarding antipsychotic therapy: A cross-sectional survey in two Norwegian hospitals. Nordic Journal of Psychiatry. 313-317.
Academic lecture
  • Show author(s) (2016). Childhood Trauma in Schizophrenia Spectrum Disorders as Compared to Other Mental Health Disorders.
  • Show author(s) (2016). An Investigation of the Potential Specificity of Childhood Maltreatment Trauma in Patients With Non-Affective Psychosis as Compared to Other Mental Health Disorders.
  • Show author(s) (2013). Prospective self-harm predicted by Borderline Personality Disorder and -criteria, and PTSD Diagnosis in patients admitted to a psychiatric acute ward.
Non-fiction book
  • Show author(s) (2005). Modernisering av offentlig sektor : utfordringer, metoder og dilemmaer. Universitetsforlaget.
  • Show author(s) (2001). Modernisering av offentlig sektor : new public management i praksis. Universitetsforlaget.
Letter to the editor
  • Show author(s) (2021). Pragmatic antipsychotics trial—caution in interpretation – Authors' reply. The Lancet Psychiatry. 101.
  • Show author(s) (2017). Re: Psykiatriens indre konflikter eksponert. Tidsskrift for Den norske legeforening. 597-597.
Doctoral dissertation
  • Show author(s) (2020). Lipid effects during antipsychotic drug treatment and their relevance for clinical outcomes.
  • Show author(s) (2019). C-reactive protein in schizophrenia-spectrum disorders; relationship to cognitive functions and medications.
  • Show author(s) (2010). Second generation antipsychotics in a naturalistic setting: effects and side effects.
  • Show author(s) (2014). C-reactive protein levels are inversely associated with neurocognitive performance in acutely admitted patients with psychosis. Schizophrenia Research. 131.
  • Show author(s) (2013). Cognitive changes in non-affective psychosis the first 4-6 weeks after admission to a psychiatric acute ward: effects of substance use. Schizophrenia Research.
  • Show author(s) (2012). Primary prevention of Psychosis (POP): a Norwegian UHR initiative. Early Intervention in Psychiatry. 117-117.
  • Show author(s) (2012). Neurocognitive functions recover from acute phase to three month-follow up in patients with non-affective psychotic disorders. Journal of the International Neuropsychological Society.
  • Show author(s) (2012). Clinical differences in acute-phase non-affective psychotic disorders with and without substance use. Schizophrenia Research.
  • Show author(s) (2010). Prediction of un-planned readmission to hospital for patients with schizophrenia - a cohort-study of 277 patients. European Neuropsychopharmacology. S444-S445.
  • Show author(s) (2007). Antipsychotic-induced hyperprolactinemia and associated symptoms: A cross-sectional survey. Nordic Journal of Psychiatry. 498-498.
  • Show author(s) (2018). Longitudinal relationship to cognitive function in acute phase of psychosis in a pragmatic, randomized trial.
  • Show author(s) (2017). The C-reactive protein in schizophrenia-spectrum disorders: relationship to cognitive function in acute phase of psychosis with a longitudinal perspective in a pragmatic, randomized trial .
  • Show author(s) (2015). Aberrant association between glutamate and salience network functional connectivity in schizophrenia.
  • Show author(s) (2012). N-acetyl aspartate and glutamate levels of the anterior cingulate predict symptoms severity in schizophrenia: a magnetic resonance spectroscopy (1H-MRS) study.
  • Show author(s) (2012). Anterior cingulate biochemistry predicts symptom severity in schizophrenia: a magnetic resonance spectroscopy (1H-MRS) study.
  • Show author(s) (2009). Differential effects of four second-generation antipsychotics on cognition in acute psychosis.
Academic literature review
  • Show author(s) (2019). Constructing the immune signature of schizophrenia for clinical use and research; an integrative review translating descriptives into diagnostics. Frontiers in Psychiatry. 1-16.
  • Show author(s) (2014). The cannabis pathway to non-affective psychosis may reflect less neurobiological vulnerability. Frontiers in Psychiatry.
  • Show author(s) (2014). Stratified medicine for mental disorders. European Neuropsychopharmacology. 5-50.
  • Show author(s) (2014). A critical review of pro-cognitive drug targets in psychosis: convergence on myelination and inflammation. Frontiers in Psychiatry.
  • Show author(s) (2013). Neuropsychopharmacology of auditory hallucinations: Insights from pharmacological MRI and perspectives for future research. Expert Review of Neurotherapeutics. 23-36.
  • Show author(s) (2012). Review: metabolic side effects of second-generation antipsychotics. Evidence-Based Mental Health.
  • Show author(s) (2012). Is rational antipsychotic polytherapy feasible? A selective review. Current Psychiatry Reports. 244-251.
  • Show author(s) (2012). Drug treatment developments in schizophrenia and bipolar mania: latest evidence and clinical usefulness. Ther Adv Chronic Dis. 287-300.
  • Show author(s) (2009). Review: second generation antipsychotics are a heterogeneous drug class. Evidence-Based Mental Health. 90-90.
  • Show author(s) (2008). Effectiveness of second generation antipsychotics: A systematic review of randomized trials. BMC Psychiatry. 14 pages.
  • Show author(s) (2020). Norsk Psykiatrisk Forening: Kliniske råd for nedtrapping og seponering av antipsykotiske legemidler.
  • Show author(s) (2020). Psykofarmakologisk behandling av psykiske lidelser. 467-502. In:
    • Show author(s) (2020). Lærebok i psykiatri Basisversjon. Gyldendal Norsk Forlag A/S.
  • Show author(s) (2018). Psykofarmakologisk behandling av psykiske lidelser. 897-976. In:
    • Show author(s) (2018). Lærebok i psykiatri. Gyldendal Akademisk.
  • Show author(s) (2016). Psykoselidelser. 104-121. In:
    • Show author(s) (2016). Psykiske lidelser. Gyldendal Akademisk.

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