Erik Johnsen
Biographic Data
| ID | 4174365 |
|---|---|
| NAME | Erik Johnsen |
| GIVEN NAMES | Erik |
| FAMILY NAME | Johnsen |
| SIGNATURE | JOHNSEN E |
| AFFILIATIONS | University of Bergen |
| ORCID | 0000-0003-0792-4436 |
| VERIFIED | Yes |
| TOTAL WORKS | 9 |
| TOTAL CITATIONS | 0 |
| AUTHOR COUNT | 9 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1962 |
| LATEST PUBLICATION YEAR | 2021 |
| H-INDEX | 0 |
The Influence of Substance Use on Side Effects of Olanzapine, Quetiapine, Risperidone, and Ziprasidone in Psychosis
BACKGROUND: Side effects restrict the optimal use of antipsychotics. Little is known about the influence of substance use on side effects. The aim of this study was to compare antipsychotic side effects in patients with psychosis with and without substance use, while also taking medication history and diagnosis into consideration. METHODS: = 226, mean age 34, females 33%) diagnosed with schizophrenia spectrum disorders (SSD; F20-F29) or other psy…
Mapping psychotic‐like experiences
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 screening questions of the Questionnaire for Psychotic Experiences (QPE), an interview that captures the presence and phenomenology of various psychotic experiences separately, to assess PLEs in Norway. Based on data from an onl…
Glutamate- and Gaba-Modulated Connectivity in Auditory Hallucinations—A Combined Resting State fMRI and MR Spectroscopy Study
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. The present study investigated if interhemispheric miscommunication is modulated at the neurochemical level by glutamate (Glu) and gamma-aminobutyric acid (GABA) concentrations in temporal and prefrontal lobe areas, as propose…
Dynamic Functional Connectivity Patterns in Schizophrenia and the Relationship With Hallucinations
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 analyses allow for explorations of temporal changes in connectivity. Thereby they also provide more detailed information on connectivity abnormalities in psychiatric disorders such as schizophrenia. The current study investigated…
Cognitive Profile in Ultra High Risk for Psychosis and Schizophrenia
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 treatment. However, there is no consensus on the cognitive profile in the UHR state, partly due to lack of valid comparisons of performance in established schizophrenia and UHR. Objectives: To compare the cognitive functioni…
The Cannabis Pathway to Non-Affective Psychosis may Reflect Less Neurobiological Vulnerability
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 suggested potential mechanisms for this effect. Recent advances in the field of neuroscience and genetics may have important implications for our understanding of this relationship. Importantly, we need to better understand the v…
An fMRI Study of Neuronal Activation in Schizophrenia Patients with and without Previous Cannabis Use
Previous studies have mostly shown positive effects of cannabis use on cognition in patients with schizophrenia, which could reflect lower neurocognitive vulnerability. There are however no studies comparing whether such cognitive differences have neuronal correlates. Thus, the aim of the present study was to compare whether patients with previous cannabis use differ in brain activation from patients who has never used cannabis. The patients grou…
A Note on the Concept of Organizational Change
Mathematical Elements in Social Sciences
No prominent works on this page.
Mathematical Elements in Social Sciences
A Note on the Concept of Organizational Change
An fMRI Study of Neuronal Activation in Schizophrenia Patients with and without Previous Cannabis Use
Previous studies have mostly shown positive effects of cannabis use on cognition in patients with schizophrenia, which could reflect lower neurocognitive vulnerability. There are however no studies comparing whether such cognitive differences have neuronal correlates. Thus, the aim of the present study was to compare whether patients with previous cannabis use differ in brain activation from patients who has never used cannabis. The patients grou…
The Cannabis Pathway to Non-Affective Psychosis may Reflect Less Neurobiological Vulnerability
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 suggested potential mechanisms for this effect. Recent advances in the field of neuroscience and genetics may have important implications for our understanding of this relationship. Importantly, we need to better understand the v…
Cognitive Profile in Ultra High Risk for Psychosis and Schizophrenia
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 treatment. However, there is no consensus on the cognitive profile in the UHR state, partly due to lack of valid comparisons of performance in established schizophrenia and UHR. Objectives: To compare the cognitive functioni…
Dynamic Functional Connectivity Patterns in Schizophrenia and the Relationship With Hallucinations
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 analyses allow for explorations of temporal changes in connectivity. Thereby they also provide more detailed information on connectivity abnormalities in psychiatric disorders such as schizophrenia. The current study investigated…
The Influence of Substance Use on Side Effects of Olanzapine, Quetiapine, Risperidone, and Ziprasidone in Psychosis
BACKGROUND: Side effects restrict the optimal use of antipsychotics. Little is known about the influence of substance use on side effects. The aim of this study was to compare antipsychotic side effects in patients with psychosis with and without substance use, while also taking medication history and diagnosis into consideration. METHODS: = 226, mean age 34, females 33%) diagnosed with schizophrenia spectrum disorders (SSD; F20-F29) or other psy…
Mapping psychotic‐like experiences
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 screening questions of the Questionnaire for Psychotic Experiences (QPE), an interview that captures the presence and phenomenology of various psychotic experiences separately, to assess PLEs in Norway. Based on data from an onl…
Glutamate- and Gaba-Modulated Connectivity in Auditory Hallucinations—A Combined Resting State fMRI and MR Spectroscopy Study
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. The present study investigated if interhemispheric miscommunication is modulated at the neurochemical level by glutamate (Glu) and gamma-aminobutyric acid (GABA) concentrations in temporal and prefrontal lobe areas, as propose…
Psychiatry (7 works) · Psychology (7 works) · Schizophrenia research and treatment (6 works) · Psychosis (5 works) · Cognition (4 works) · Medicine (4 works) · Audiology (3 works) · Clinical Psychology (3 works) · Neuroscience (3 works) · Schizophrenia (object-oriented programming (3 works)