Nikolai Olavi Czajkowski
Biographic Data
| ID | 5803969 |
|---|---|
| NAME | Nikolai Olavi Czajkowski |
| GIVEN NAMES | Nikolai Olavi |
| FAMILY NAME | Czajkowski |
| SIGNATURE | CZAJKOWSKI N O |
| AFFILIATIONS | Norwegian Institute of Public Health |
| ORCID | 0000-0002-3713-653X |
| VERIFIED | Yes |
| TOTAL WORKS | 19 |
| TOTAL CITATIONS | 1 |
| WORKS AS AUTHOR | 19 |
| WORKS AS EDITOR | 0 |
| FIRST PUBLICATION YEAR | 2015 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 1 |
The Relationship Between Educational Attainment and Right-Wing Authoritarianism
While it is well-established that educational attainment and Right-Wing Authoritarianism (RWA) are negatively correlated, it remains unclear why, as causal effects are hard to distinguish from the effects of confounders. Here, we use an adaptation of the discordant twin design in a structural equation framework (ACE-β models) with 1264 Norwegian monozygotic and dizygotic twins, to investigate whether education and RWA remain associated after cont…
Mental illbeing and wellbeing are influenced by recent adverse life events. Evidence from a longitudinal twin study
Adverse life events have been associated with increased mental illbeing and decreased wellbeing. These associations may partly reflect reverse causality and confounding genetics. Few studies have accounted for such effects, and few have compared the effect of adversities within and across different mental health outcomes. Our sample includes 1987 monozygotic and dizygotic twins born 1945-60, in the Norwegian Twin Registry, who responded to two qu…
Longitudinal recovery and self-efficacy in first-episode schizophrenia
A significant proportion of first-episode schizophrenia patients can achieve clinical recovery. While these positive outcomes are noteworthy, it is important to recognize that recovery paths can vary widely among individuals. Since people with schizophrenia are concerned about their chances of recovery, the results must be shared with patients and their families. While the causal relationship between self-efficacy and recovery remains unclear, th…
Use of antidepressant medication is associated with slower response to open-ended psychotherapy for depressed patients
Medicated patients may experience less response to psychotherapy in terms of depressive symptoms and interpersonal problems compared to nonmedicated patients
Reconsidering False Positives in Machine Learning Binary Classification Models of Suicidal Behavior
We posit the hypothesis that False Positive cases (FP) in machine learning classification models of suicidal behavior are at risk of suicidal behavior and should not be seen as sheer classification error. We trained an XGBoost classification model using survey data from 173,663 Norwegian adolescents and compared the classification groups for several suicide-related mental health indicators, such as depression, anxiety, psychological distress, and…
The genetic underpinnings of right‐wing authoritarianism and social dominance orientation explain political attitudes beyond Big Five personality
OBJECTIVE: Political attitudes are predicted by the key ideological variables of right-wing authoritarianism (RWA) and social dominance orientation (SDO), as well as some of the Big Five personality traits. Past research indicates that personality and ideological traits are correlated for genetic reasons. A question that has yet to be tested concerns whether the genetic variation underlying the ideological traits of RWA and SDO has distinct contr…
Unveiling Adolescent Suicidality
Adolescent suicide attempts are on the rise, presenting a significant public health concern. Recent research aimed at improving risk assessment for adolescent suicide attempts has turned to machine learning. But no studies to date have examined the performance of stacked ensemble algorithms, which are more suitable for low-prevalence conditions. The existing machine learning-based research also lacks population-representative samples, overlooks p…
The longitudinal relationship between life events and loneliness in adolescence
The aim of the study was to examine associations between life events and self-assessed loneliness in adolescence. We used data from a Norwegian population-based twin sample including seven birth cohorts ( N = 2,879, 56% females). The participants completed self-report questionnaires three times throughout adolescence, with 2 years in between (i.e., 12-18 years old at Wave 1). By using a random intercept cross-lagged panel model (RI-CLPM), we were…
Co-occurrence of internalizing difficulties and aggression in early childhood and risk of mental health problems in middle childhood
The goal of this prospective longitudinal study was to explore whether co-occurrent internalizing difficulties and aggression in early childhood convey increased risk for later mental health problems in middle childhood. Participants were mothers from the Norwegian Mother, Father and Child Cohort Study (MoBa), who provided assessments of child internalizing difficulties and aggression at ages 3 years ( n = 54,644; 26,750 girls) and 5 years ( n = …
Predicting suicide attempts among Norwegian adolescents without using suicide-related items
This study underscores the potential of machine learning for screening adolescent suicide attempts on a population scale without requiring sensitive suicide-related survey items. Future research investigating the etiology of suicidal behavior may direct particular attention to internalizing problems, interpersonal relationships, victimization, and substance use
The structure of well-being
Our findings yield novel insights into the structure of well-being and genetic and environmental influences on general well-being factors, with implications for well-being and mental health research, including genetically informative studies
Effects of a school-based intervention on levels of anxiety and depression
No effects of the intervention were found. This large universal school-based trial suffered from considerable drop-out of participants. Experiences from implementation and evaluation of universal mental health promotion and preventive school interventions are thoroughly discussed, including, preparation, resources, support, time, realistic expectations, teacher selection and training, implementation, research designs and more. Several empirically…
The relationship between life events and sense of coherence in adolescence. A longitudinal twin study
This three-wave study examined the relationship between life events and sense of coherence (SOC) throughout adolescence by using genetically informative random intercept cross-lagged panel models. We also examined the genetic and environmental contribution to variance in the measured constructs. The data come from a Norwegian population-based twin sample (N = 2,878). Life events and SOC were associated, and both showed substantial genetic varianc…
The longitudinal association between symptoms of posttraumatic stress and complicated grief
Findings suggest that targeting PTSD symptoms among trauma-exposed bereaved may hinder later development of complicated grief. (PsycInfo Database Record (c) 2022 APA, all rights reserved)
Does stereopsis improve face identification? A study using a virtual reality display with integrated eye-tracking and pupillometry
Stereopsis is a powerful depth cue for humans, which may also contribute to object recognition. In particular, we surmise that face identification would benefit from the availability of stereoscopic depth cues, since facial perception may be based on three-dimensional (3D) representations. In this study, a virtual reality (VR) headset with integrated eye-tracking was used to present stereoscopic images of faces. As a monoscopic contrast condition…
Therapeutic Atmosphere in Psychotherapy Sessions
There is uncertainty concerning what the active ingredients in psychotherapy are. The First Experimental Study of Transference interpretations (FEST) was a randomized controlled trial of the effects of transference work (TW) in psychodynamic psychotherapy. Women with low quality of object relations (QOR) showed a large positive effect of transference work, while men with high QOR showed a slight negative effect. The present study aimed to expand …
Conflict with Parents in Adolescent Depression
Conflict with parents is common among depressed adolescents, interferes with treatment, and may increase risk of recurrence. Parental depressive symptoms have been shown to predict conflict with adolescent children, but an important role for different kinds of parental interpersonal problems, as described by interpersonal circumplex, is also plausible. This study compared parental interpersonal problems to parental depressive symptoms as predicto…
Does low alcohol use increase the risk of sickness absence? A discordant twin study
The increased level of sick leave observed with low level drinkers seems to be mainly explained by confounding from genetic factors. In all observational studies of the relationship between alcohol consumption and health, one should be aware that important genetic confounders are likely to influence the results
Socioeconomic status and sick leave granted for mental and somatic disorders
Low SES is associated with a higher level of sick leave granted for both mental and somatic disorders among young adults, but these associations are confounded by factors that are common to co-twins. Education and income are therefore not likely to strongly affect sick leave in young adulthood
Unveiling Adolescent Suicidality
Adolescent suicide attempts are on the rise, presenting a significant public health concern. Recent research aimed at improving risk assessment for adolescent suicide attempts has turned to machine learning. But no studies to date have examined the performance of stacked ensemble algorithms, which are more suitable for low-prevalence conditions. The existing machine learning-based research also lacks population-representative samples, overlooks p…
Socioeconomic status and sick leave granted for mental and somatic disorders
Low SES is associated with a higher level of sick leave granted for both mental and somatic disorders among young adults, but these associations are confounded by factors that are common to co-twins. Education and income are therefore not likely to strongly affect sick leave in young adulthood
Does low alcohol use increase the risk of sickness absence? A discordant twin study
The increased level of sick leave observed with low level drinkers seems to be mainly explained by confounding from genetic factors. In all observational studies of the relationship between alcohol consumption and health, one should be aware that important genetic confounders are likely to influence the results
Does stereopsis improve face identification? A study using a virtual reality display with integrated eye-tracking and pupillometry
Stereopsis is a powerful depth cue for humans, which may also contribute to object recognition. In particular, we surmise that face identification would benefit from the availability of stereoscopic depth cues, since facial perception may be based on three-dimensional (3D) representations. In this study, a virtual reality (VR) headset with integrated eye-tracking was used to present stereoscopic images of faces. As a monoscopic contrast condition…
Therapeutic Atmosphere in Psychotherapy Sessions
There is uncertainty concerning what the active ingredients in psychotherapy are. The First Experimental Study of Transference interpretations (FEST) was a randomized controlled trial of the effects of transference work (TW) in psychodynamic psychotherapy. Women with low quality of object relations (QOR) showed a large positive effect of transference work, while men with high QOR showed a slight negative effect. The present study aimed to expand …
Conflict with Parents in Adolescent Depression
Conflict with parents is common among depressed adolescents, interferes with treatment, and may increase risk of recurrence. Parental depressive symptoms have been shown to predict conflict with adolescent children, but an important role for different kinds of parental interpersonal problems, as described by interpersonal circumplex, is also plausible. This study compared parental interpersonal problems to parental depressive symptoms as predicto…
The longitudinal association between symptoms of posttraumatic stress and complicated grief
Findings suggest that targeting PTSD symptoms among trauma-exposed bereaved may hinder later development of complicated grief. (PsycInfo Database Record (c) 2022 APA, all rights reserved)
Effects of a school-based intervention on levels of anxiety and depression
No effects of the intervention were found. This large universal school-based trial suffered from considerable drop-out of participants. Experiences from implementation and evaluation of universal mental health promotion and preventive school interventions are thoroughly discussed, including, preparation, resources, support, time, realistic expectations, teacher selection and training, implementation, research designs and more. Several empirically…
The relationship between life events and sense of coherence in adolescence. A longitudinal twin study
This three-wave study examined the relationship between life events and sense of coherence (SOC) throughout adolescence by using genetically informative random intercept cross-lagged panel models. We also examined the genetic and environmental contribution to variance in the measured constructs. The data come from a Norwegian population-based twin sample (N = 2,878). Life events and SOC were associated, and both showed substantial genetic varianc…
Co-occurrence of internalizing difficulties and aggression in early childhood and risk of mental health problems in middle childhood
The goal of this prospective longitudinal study was to explore whether co-occurrent internalizing difficulties and aggression in early childhood convey increased risk for later mental health problems in middle childhood. Participants were mothers from the Norwegian Mother, Father and Child Cohort Study (MoBa), who provided assessments of child internalizing difficulties and aggression at ages 3 years ( n = 54,644; 26,750 girls) and 5 years ( n = …
Predicting suicide attempts among Norwegian adolescents without using suicide-related items
This study underscores the potential of machine learning for screening adolescent suicide attempts on a population scale without requiring sensitive suicide-related survey items. Future research investigating the etiology of suicidal behavior may direct particular attention to internalizing problems, interpersonal relationships, victimization, and substance use
The structure of well-being
Our findings yield novel insights into the structure of well-being and genetic and environmental influences on general well-being factors, with implications for well-being and mental health research, including genetically informative studies
Reconsidering False Positives in Machine Learning Binary Classification Models of Suicidal Behavior
We posit the hypothesis that False Positive cases (FP) in machine learning classification models of suicidal behavior are at risk of suicidal behavior and should not be seen as sheer classification error. We trained an XGBoost classification model using survey data from 173,663 Norwegian adolescents and compared the classification groups for several suicide-related mental health indicators, such as depression, anxiety, psychological distress, and…
The genetic underpinnings of right‐wing authoritarianism and social dominance orientation explain political attitudes beyond Big Five personality
OBJECTIVE: Political attitudes are predicted by the key ideological variables of right-wing authoritarianism (RWA) and social dominance orientation (SDO), as well as some of the Big Five personality traits. Past research indicates that personality and ideological traits are correlated for genetic reasons. A question that has yet to be tested concerns whether the genetic variation underlying the ideological traits of RWA and SDO has distinct contr…
Unveiling Adolescent Suicidality
Adolescent suicide attempts are on the rise, presenting a significant public health concern. Recent research aimed at improving risk assessment for adolescent suicide attempts has turned to machine learning. But no studies to date have examined the performance of stacked ensemble algorithms, which are more suitable for low-prevalence conditions. The existing machine learning-based research also lacks population-representative samples, overlooks p…
The longitudinal relationship between life events and loneliness in adolescence
The aim of the study was to examine associations between life events and self-assessed loneliness in adolescence. We used data from a Norwegian population-based twin sample including seven birth cohorts ( N = 2,879, 56% females). The participants completed self-report questionnaires three times throughout adolescence, with 2 years in between (i.e., 12-18 years old at Wave 1). By using a random intercept cross-lagged panel model (RI-CLPM), we were…
Mental illbeing and wellbeing are influenced by recent adverse life events. Evidence from a longitudinal twin study
Adverse life events have been associated with increased mental illbeing and decreased wellbeing. These associations may partly reflect reverse causality and confounding genetics. Few studies have accounted for such effects, and few have compared the effect of adversities within and across different mental health outcomes. Our sample includes 1987 monozygotic and dizygotic twins born 1945-60, in the Norwegian Twin Registry, who responded to two qu…
Longitudinal recovery and self-efficacy in first-episode schizophrenia
A significant proportion of first-episode schizophrenia patients can achieve clinical recovery. While these positive outcomes are noteworthy, it is important to recognize that recovery paths can vary widely among individuals. Since people with schizophrenia are concerned about their chances of recovery, the results must be shared with patients and their families. While the causal relationship between self-efficacy and recovery remains unclear, th…
Use of antidepressant medication is associated with slower response to open-ended psychotherapy for depressed patients
Medicated patients may experience less response to psychotherapy in terms of depressive symptoms and interpersonal problems compared to nonmedicated patients
The Relationship Between Educational Attainment and Right-Wing Authoritarianism
While it is well-established that educational attainment and Right-Wing Authoritarianism (RWA) are negatively correlated, it remains unclear why, as causal effects are hard to distinguish from the effects of confounders. Here, we use an adaptation of the discordant twin design in a structural equation framework (ACE-β models) with 1264 Norwegian monozygotic and dizygotic twins, to investigate whether education and RWA remain associated after cont…
Psychology (16 works) · Clinical Psychology (11 works) · Medicine (11 works) · Psychiatry (9 works) · Clinical Psychology (8 works) · Developmental psychology (7 works) · Norwegian (6 works) · Population (6 works) · Twin study (6 works) · Anxiety (5 works)