Research Interests: Psychology, Clinical Psychology, Psychiatry, Personality, Schizophrenia, and 15 moreBorderline Personality Disorder, Medicine, Impulsivity, Humans, Impulse Control Disorders, Major Depressive Disorder, Female, Male, Dissociative disorders, Dissociative experiences scale, Mental Disorders, Fantasy, Clinical Sciences, Questionnaires, and Adult
Research Interests: Mental Health, Medicine, Crisis Intervention, Humans, Needs Assessment, and 15 moreINTENSIVE CARE, Female, Male, Continuity of Care, Clinical Sciences, Middle Aged, Adult, Observational Study, Continuity of Patient Care, Community Based Mental Health Services, Case Control Studies, Cumulant, Measurement System, Outcome measure, and Adverse effect
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Systems of intensive care such as the Function Assertive Community Treatment (Function-act) are advocated because they are reported to have achieved very promising results. However, comparative studies aimed at measuring the efficacy of... more
Systems of intensive care such as the Function Assertive Community Treatment (Function-act) are advocated because they are reported to have achieved very promising results. However, comparative studies aimed at measuring the efficacy of such systems are mainly of short duration and the outcome measure is nearly always the amount of care provided. To investigate, via an observational study, changes that occurred in the number of patients going into remission and in the amount of care provided before and after the introduction of f-act. f-act was introduced in Maastricht and the surrounding area (population 220,000) at the beginning of 2002. Cumulative routine measurements of the effect of care in the region had been performed since 1998. These measurements were used to compare the proportion of patients in remission in two non-overlapping patients cohorts, each covering a 4-year period, namely 1998-2001 and 2002-2005. results The proportion of patients who made the transition to remi...
Research Interests: Community-Based Mental Health Services, Quality of life, Quality of Mental Health Care, Treatment Outcome, Medicine, and 14 morePopulation, Humans, Female, Male, Netherlands, Mental Disorders, Assertiveness, Aged, Middle Aged, Adult, Observational Study, Community Based Mental Health Services, confounding, and Quality of health care
Research Interests: Psychology, Psychiatry, Medicine, Psychological Medicine, Humans, and 11 moreAggression, Mental Disorders, Public health systems and services research, Psychiatric Services, Psychiatric, Psychological Models, Inpatients, Cognition disorders, Severity of Illness Index, Psychiatric Status Rating Scales, and Patients' rooms
Research Interests: Cognitive Science, Health Care, Health Services Research, Medicine, Humans, and 15 moreNeeds Assessment, Feedback, Netherlands, Mental Disorders, Clinical Sciences, Middle Aged, Adult, Patient Care Team, Monitoring System, Monitor, Community Based Mental Health Services, Cumulant, Databases as topic, Health Care Surveys, and Patient care management
The purpose of this study was twofold. Firstly, to evaluate the reliability and usefulness of the Staff Observation Aggression Scale (SOAS), an instrument for measuring aggressive behaviour in the clinical situation. Secondly, to examine... more
The purpose of this study was twofold. Firstly, to evaluate the reliability and usefulness of the Staff Observation Aggression Scale (SOAS), an instrument for measuring aggressive behaviour in the clinical situation. Secondly, to examine the incidence of aggressive incidents and the circumstances under which they occur on an acute psychiatric admissions ward. During a period of 24 weeks 164 aggressive incidents were recorded. The SOAS proved to be a suitable instrument for measuring aggressive behaviour with fair-to-good inter-reported reliability. Aggressive behaviour was especially likely to occur in the afternoon from noon to 3.00 p.m. It frequently took place in the day-rooms of the ward, in or near the staff office, and in front of the locked exit door of the ward. Patients involved in the incidents were younger and more often involuntarily admitted - than non-aggressive control patients. Gender and diagnosis were not found to be related to aggressive behaviour.
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Admissions for irreversible psychosurgical treatment of obsessive-compulsive disorder (OCD) by the Working Group for Indication Psychosurgery in the Netherlands were analyzed, and the postsurgical effects on symptom severity and quality... more
Admissions for irreversible psychosurgical treatment of obsessive-compulsive disorder (OCD) by the Working Group for Indication Psychosurgery in the Netherlands were analyzed, and the postsurgical effects on symptom severity and quality of life were evaluated. The data were extracted from patient records in the period 2001-2008, and there was a postoperative assessment with a semistructured interview. Fourteen patients applied, having severe OCD with mostly one or more comorbid disorders. The mean Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score was 32 points. Four of seven patients in whom psychosurgery was deemed useful were operated on. The decrease of the Y-BOCS score from registration to after surgery was 9 points (range, 3-17 points). An improvement in social function was present in three of four patients. In conclusion, psychosurgery can be a valuable treatment option for patients with severe OCD in whom other treatments fail.
Research Interests: Psychology, Cognitive Science, Quality of life, Treatment Outcome, Brain, and 14 moreHumans, Caudate Nucleus, Female, Male, Obsessive Compulsive Disorder, Follow-up studies, Netherlands, Clinical Sciences, Middle Aged, Adult, Time Factors, Neural pathways, Psychosurgery, and Severity of Illness Index
Psychometric symptom validity assessment is becoming increasingly part and parcel of psychological and neuropsychological assessments. An unresolved and rarely addressed issue concerns the differentiation between factitious and malingered... more
Psychometric symptom validity assessment is becoming increasingly part and parcel of psychological and neuropsychological assessments. An unresolved and rarely addressed issue concerns the differentiation between factitious and malingered symptom presentations: present-day symptom validity tests can assess whether an examinee presents with noncredible symptomatology, but not why an examinee does so. We explored this issue by developing the Symptom and Disposition Interview (SDI); a symptom validity test that incorporates strategies intended to gauge internal incentives associated with factitious disorder. The merits of the SDI were explored and compared to a traditional symptom validity test (the Structured Inventory of Malingered Symptomatology) in two analogue studies, each with factitious and malingering conditions (n = 24-30 per condition) and a clinical control group (n = 34, n = 40). Overall, the results were positive: The SDI was as effective in detecting feigned symptom pres...
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This study examined whether staff members' use of interventions for preventing patients' aggression reduced the number of incidents of aggression on a closed acute admissions ward of a psychiatric hospital in the Netherlands. The... more
This study examined whether staff members' use of interventions for preventing patients' aggression reduced the number of incidents of aggression on a closed acute admissions ward of a psychiatric hospital in the Netherlands. The number and severity of incidents of aggression on three closed wards were measured using the Dutch version of the Staff Observation Aggression Scale (SOAS). Measurements were made for three months before and after staff implemented interventions for preventing aggression on one of the wards. Interventions included a protocol for talking to patients who exhibited aggressive behavior, discussing treatment goals with the patient shortly after admission, explaining why the ward's door was locked and the exit rules, providing a schedule of staff meetings to explain staff members' absence from the ward, and clarifying the procedure for making an appointment with the psychiatrists. The frequency of aggressive incidents was reduced on all three ward...
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Research Interests: Skin conductance and ACTA
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In the Netherlands it has recently become possible for transsexual patients to receive hormonal treatment from the onset of puberty. Until the age of 16, pubertal development can be prevented with luteinizing hormone-releasing hormone... more
In the Netherlands it has recently become possible for transsexual patients to receive hormonal treatment from the onset of puberty. Until the age of 16, pubertal development can be prevented with luteinizing hormone-releasing hormone (LHRH) agonists. From 16 years of age onwards, gender adjustment can be initiated by administration of hormones of the opposite sex. Surgical treatment can be offered once the patient reaches 18 years of age. Although such treatment will only be initiated with reticence and after a long phase of intense diagnostic screening, the question arises whether a clear differentiation can be made between pure gender identity disorders and secondary transsexual feelings that are part of an ongoing psychopathological development, such as schizophrenia. The potential diagnostic confusion is illustrated by a case history of a male schizophrenic patient. This patient had been treated hormonally for transsexualism for years before acute psychotic decompensation occur...
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Auto-aggressive individuals have a higher likelihood of engaging in interpersonal violence, and vice versa. It is unclear, however, whether ward circumstances are involved in determining whether aggression-prone patients will engage in... more
Auto-aggressive individuals have a higher likelihood of engaging in interpersonal violence, and vice versa. It is unclear, however, whether ward circumstances are involved in determining whether aggression-prone patients will engage in auto-aggressive or outwardly directed aggressive behavior. The current study focuses on the situational antecedents of self-harming behavior and outwardly directed aggression of psychiatric inpatients. Inwardly and outwardly aggressive behavior were monitored on a locked 20-bed psychiatric admissions ward for 3.5 years with the Staff Observation Aggression Scale-Revised (SOAS-R). A map of the ward was attached to each SOAS-R form, enabling staff members to specify locations of aggressive incidents. Time of onset, location, and provoking factors of auto-aggressive incidents were compared to those connected to aggression against others or objects. Of a total of 774 aggressive incidents, 154 (20%) concerned auto-aggressive behavior. Auto-aggression was significantly more prevalent during the evening (i.e., 50% compared to 32%), and reached its highest level between 8 and 9 P.M. (17% compared to 7%). The majority of self-harming acts (66%) were performed on patients' bedrooms. Outwardly directed aggression was particularly common in the day-rooms (24%), the staff office (19%), the hallways of the ward (14%), and the dining rooms (10%). Provoking factors of auto-aggressive behavior are less often of an interactional nature compared to outwardly directed aggression. The results suggest that a lack of stimulation and interaction with others increases the risk of self-injurious behavior. Practical and testable measures to prevent self-harm are proposed.
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Research Interests: Psychometrics, Schizophrenia, Social Cognition, Theory of Mind, Attention, and 22 moreSemantic Memory, Adolescent, Information Processing, Social behavior, Factor analysis, Humans, Judgment, Female, Male, Personal Construct Theory, Psychotic Disorder, Risk factors, Awareness, Middle Aged, Adult, Reproducibility of Results, Psychotic Disorders, Risk Factors, Social Behavior, Source Monitoring, Cognition disorders, and Data Gathering
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The aims of the study were to investigate whether (i) patients with lifetime presence of non-affective psychosis show an external-personal attribution bias for negative events, (ii) this attribution style can also be detected in... more
The aims of the study were to investigate whether (i) patients with lifetime presence of non-affective psychosis show an external-personal attribution bias for negative events, (ii) this attribution style can also be detected in first-degree relatives of patients with psychosis and subjects with subclinical psychotic experiences, and (iii) this attribution style is related to the presence of psychotic symptoms, in particular delusions. Participants were 23 patients with lifetime presence of non-affective psychosis, a high- risk group of 36 first-degree relatives of patients with non-affective psychosis, a high-risk group of 31 subjects with subclinical psychotic experiences and 46 normal controls. Attribution style was measured by the Internal, Personal and Situational Attribution Questionnaire. Positive symptoms were assessed with the Present State Examination (PSE) and the Scale for the Assessment of Positive Symptoms (SAPS). Relative to the controls, an externalizing bias was apparent in the patient group (beta = 0.20, p = 0.03) but not in the two high-risk groups. There was a dose-response association between externalizing bias and the delusions subscale of the PSE (relative to lowest level: highest level of delusions: beta = 0.53, p = 0.04; intermediate levels of delusions: beta = 0.23, p = 0.35). No significant differences were found in personalizing bias between the four groups. Patients with psychosis tend to use an externalizing bias in their explanations of negative social events, and this bias is associated with the presence of positive psychotic symptoms, in particular delusions. A deviant attribution style is not part of the vulnerability to psychosis.
Research Interests: Psychology, Social Perception, Adolescent, Delusions, Psychological Medicine, and 17 moreSocial behavior, Humans, Female, Male, Risk factors, Patients, Middle Aged, Questionnaires, Adult, Public health systems and services research, Reproducibility of Results, Psychotic Disorders, Risk Factors, Social Behavior, Bias (Epidemiology), Neurosciences, and Life Change Events
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Little is known about the experiential dynamics of the interaction between cannabis and vulnerability to psychosis. To examine the effects of cannabis on psychotic symptoms and mood in patients with psychosis and healthy controls.... more
Little is known about the experiential dynamics of the interaction between cannabis and vulnerability to psychosis. To examine the effects of cannabis on psychotic symptoms and mood in patients with psychosis and healthy controls. Patients with a psychotic disorder (n = 42) and healthy controls (n = 38) were followed in their daily lives using a structured time-sampling technique. Daily life cannabis use predicted subsequent increases in positive affect and in patients, but not in controls, decreases in negative affect. In patients, but not in controls, cannabis use predicted increased levels of hallucinatory experiences. Mood-enhancing properties of cannabis were acute, whereas psychosis-inducing effects were sub-acute. There was no direct evidence for self-medication effects in daily life. Patients with psychosis are more sensitive to both the psychosis-inducing and mood-enhancing effects of cannabis. The temporal dissociation between acute rewarding effects and sub-acute toxic influences may be instrumental in explaining the vicious circle of deleterious use in these patients.
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A disorder of self-monitoring may underlie the positive symptoms of psychosis. The cognitive mechanisms associated with these symptoms may also be detectable in individuals at risk of psychosis. To investigate (a) whether patients with... more
A disorder of self-monitoring may underlie the positive symptoms of psychosis. The cognitive mechanisms associated with these symptoms may also be detectable in individuals at risk of psychosis. To investigate (a) whether patients with psychosis show impaired self-monitoring, (b) to what degree this is associated with positive symptoms, and (c) whether this is associated with liability to psychotic symptoms. The sample included: individuals with a lifetime history of non-affective psychosis (n=37), a genetically defined risk group (n=41), a psychometrically defined risk group (n=40), and control group (n=49). All participants carried out an action-recognition task. Number of action-recognition errors was associated with psychosis risk (OR linear trend over 3 levels:1.12, 95% CI1.04-1.20) and differential error rate was associated with the degree of delusional ideation in a dose-response fashion (OR linear trend over 3 levels:1.13, 95% CI1.00-1.26). Alterations in self-monitoring are associated with psychosis with evidence of specificity for delusional ideation. In the risk state, this is expressed more as failure to recognise self-generated actions, whereas in illness failure to recognise alien sources come to the fore.