Aan de Open Universiteit is onlangs een onderzoek naar de onbewuste determinanten van snackgedrag gestart. Met behulp van Snackimpuls, een smartphone applicatie gebaseerd op de Experience Sampling Methode, wordt in het dagelijks leven... more
Aan de Open Universiteit is onlangs een onderzoek naar de onbewuste determinanten van snackgedrag gestart. Met behulp van Snackimpuls, een smartphone applicatie gebaseerd op de Experience Sampling Methode, wordt in het dagelijks leven onderzocht of determinanten zoals gewoonte, stress, emoties en zelfwaardering van invloed zijn op snackgedrag. Saskia Wouters en collega's deden een pilot-studie naar de bruikbaarheid van deze applicatie. Research investigating determinants of unhealthy eating behaviour has mainly focussed on conscious (reasoned) processes. However, recent research suggests that unconsious (impulsive) processes are also crucial in predicting unhealthy eating. Snackimpuls, a smartphone application based on the Experience Sampling Method, was specifically developed at the Open University to gain insight into the unconscious determinants of between-meal snacking and their dynamic interplay in daily life.
Research Interests:
Research Interests:
Research Interests:
The previously reported but still poorly investigated link between deafness or hearing impairment (DHI) and the onset of positive psychotic experiences was investigated prospectively in a general population sample. Of the 109 DHI subjects... more
The previously reported but still poorly investigated link between deafness or hearing impairment (DHI) and the onset of positive psychotic experiences was investigated prospectively in a general population sample. Of the 109 DHI subjects at baseline, 11 (10.1%) displayed psychotic experiences at T(2) versus 137 (2.9%) of the non-DHI subjects (OR=3.8, 95% CI: 2.0, 7.2). This effect size was only slightly attenuated after adjustment for baseline psychotic experiences (OR=3.2, 95% CI: 1.6, 6.5) and after adjustment for T(0) psychotic experiences and a range of other confounders (OR=3.0, 95% CI: 1.4, 6.2) These results confirm previous findings of an association between hearing impairments and psychosis and show that this association can also be found prospectively in a nonclinical population.
Research Interests: Schizophrenia, Comorbidity, Prospective studies, Humans, Effect size, and 17 moreFemale, Male, Netherlands, Incidence, Hearing Loss, Risk factors, Deafness, Middle Aged, Longitudinal Studies, Adult, Hearing Impaired, Health surveys, Psychotic Disorders, Risk Factors, Cross Sectional Studies, General Population, and Cohort Studies
Research Interests:
Research on the association between paranoia and self-esteem has yielded inconsistent findings. Some studies have indicated an association between paranoia and low self-esteem, while other studies have shown an association with high... more
Research on the association between paranoia and self-esteem has yielded inconsistent findings. Some studies have indicated an association between paranoia and low self-esteem, while other studies have shown an association with high self-esteem. A plausible explanation for these inconsistencies is that self-esteem is unstable in paranoid individuals. The association between instability in self-esteem and paranoia was assessed in a general population risk set of 4636 individuals using logistic regression analysis. Self-esteem instability was significantly associated with the presence of paranoid symptoms (OR 1.27 95% CI 1.12-1.45) and not with other positive psychotic symptoms (OR 1.09 95% CI 0.96-1.23), adjusted for a range of a priori selected confounders. The finding of a specific association between unstable self-esteem and paranoia is in line with a recent psychological model suggesting that paranoid beliefs arise partly as a consequence of dysfunctional efforts to regulate self-esteem.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Deficits in emotion processing are thought to underlie the key negative symptoms flat affect and anhedonia observed in psychotic disorders. This study investigated emotional experience and social behavior in the realm of daily life in a... more
Deficits in emotion processing are thought to underlie the key negative symptoms flat affect and anhedonia observed in psychotic disorders. This study investigated emotional experience and social behavior in the realm of daily life in a sample of patients with schizophrenia and schizoaffective disorder, stratified by level of negative symptoms. Emotional experience and behavior of 149 patients with schizophrenia and schizoaffective disorder and 143 controls were explored using the Experience Sampling Method. Patients reported lower levels of positive and higher levels of negative affect compared with controls. High negative symptom patients reported similar emotional stability and capacity to generate positive affect as controls, whereas low negative symptom patients reported increased instability. All participants displayed roughly comparable emotional responses to the company of other people. However, in comparison with controls, patients showed more social withdrawal and preference to be alone while in company, particularly the high negative symptom group. This study revealed no evidence for a generalized hedonic deficit in patients with psychotic spectrum disorders. Lower rather than higher levels of negative symptoms were associated with a pattern of emotional processing which was different from healthy controls.
Research Interests:
Research Interests:
Research Interests:
Experimental studies have indicated that social contact, even when it is neutral, triggers paranoid thinking in people who score high on clinical or subclinical paranoia. We investigated whether contextual variables are predictive of... more
Experimental studies have indicated that social contact, even when it is neutral, triggers paranoid thinking in people who score high on clinical or subclinical paranoia. We investigated whether contextual variables are predictive of momentary increases in the intensity of paranoid thinking in a sample of participants ranging across a psychometric paranoia continuum. The sample (n=154) consisted of 30 currently paranoid patients, 34 currently non-paranoid patients, 15 remitted psychotic patients, 38 high-schizotypy participants, and 37 control subjects. Based on their total score on Fenigstein's Paranoia Scale (PS), three groups with different degrees of paranoia were defined. The Experience Sampling Method (ESM), a structured diary technique, was used to assess momentary social context, perceived social threat and paranoia in daily life. There were differences in the effect of social company on momentary levels of paranoia and perceived social threat across the range of trait paranoia. The low and medium paranoia groups reported higher levels of perceived social threat when they were with less-familiar compared to familiar individuals. The medium paranoia group reported more paranoia in less-familiar company. The high paranoia group reported no difference in the perception of social threat or momentary paranoia between familiar and unfamiliar contacts. Paranoid thinking is context dependent in individuals with medium or at-risk levels of trait paranoia. Perceived social threat seems to be context dependent in the low paranoia group. However, at high levels of trait paranoia, momentary paranoia and momentary perceived social threat become autonomous and independent of social reality.
Research Interests:
Research Interests: Psychology, Adolescent Development, Adolescent, Psychological Medicine, Germany, and 13 moreProspective studies, Humans, Psychological, Female, Male, Confidence intervals, Young Adult, Hearing Loss, Public health systems and services research, Odds ratio, Psychotic Disorders, Neurosciences, and Age of Onset
Research Interests:
Studies investigating the relationship between self-esteem and paranoia have specifically focused on self-esteem level, but have neglected the dynamic aspects of self-esteem. In the present article, the authors investigated the... more
Studies investigating the relationship between self-esteem and paranoia have specifically focused on self-esteem level, but have neglected the dynamic aspects of self-esteem. In the present article, the authors investigated the relationship between self-esteem and paranoia in two different ways. First, 154 individuals ranging across the continuum in level of paranoia were studied with the Experience Sampling Method (a structured self-assessment diary technique) to assess the association between trait paranoia and level and fluctuation of self-esteem in daily life. Results showed that trait paranoia was associated with both lower levels and higher instability of self-esteem. Second, the temporal relationship between momentary (state) paranoia and self-esteem was investigated in the daily life of these individuals. Results showed that a decrease in self-esteem was associated with an immediate increase in paranoia. The findings indicate that paranoid individuals are not only characterized by a lower level of self-esteem but also by more fluctuations in their self-esteem and that fluctuations in self-esteem predict the degree of subsequent paranoia. These results are consistent with the hypothesis that paranoia is associated with dysfunctional strategies of self-esteem regulation.
Research Interests:
The interplay between the catechol-O-methyltransferase (COMT) Val158Met polymorphism and environmental stress may have etiological relevance for psychosis, but differential effects have been reported in healthy control and patient groups,... more
The interplay between the catechol-O-methyltransferase (COMT) Val158Met polymorphism and environmental stress may have etiological relevance for psychosis, but differential effects have been reported in healthy control and patient groups, suggesting that COMT Val158Met interactions with stress may be conditional on background genetic risk for psychotic disorder. Patients with a nonaffective psychotic disorder (n = 86) and control participants (n = 109) were studied with the experience sampling method (a structured diary technique) in order to assess stress, negative affect and momentary psychotic symptoms in the flow of daily life. Multilevel analyses revealed significant three-way interactions between group status (patient or control), COMT genotype and stress in the model of negative affect (χ(2)(2) = 13.26, P < 0.01) as well as in the model of momentary psychotic symptoms (χ(2)(2) = 6.92, P < 0.05). Exploration of the three-way interaction revealed that in patients, COMT genotype moderated the association between stress and negative affect (χ(2)(4) = 11.50, P < 0.005), as well as the association between stress and momentary psychosis (χ(2)(4) = 12.79, P < 0.005). Met/Met genotype patients showed significantly increased psychotic and affective reactivity to stress in comparison to the Val/Met and Val/Val genotypes. In contrast, healthy controls did not display large or significant COMT Val158Met X stress interactions. Important differences exist in the effect of COMT Val158Met on stress reactivity, which may depend on background risk for psychotic disorder. Differential sensitivity to environmental stress occasioned by COMT Val158Met may be contingent on higher order interactions with genetic variation underlying psychotic disorder.