Nynke Boonstra

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BACKGROUND Longer duration of untreated psychosis (DUP) is associated with poorer outcome in terms of positive symptoms, relapse rate, and time to remission. In contrast, the association with negative symptoms is less consistent. AIMS The study had three aims. First, to arrive at a more precise estimate of the correlation between DUP and negative symptoms(More)
BACKGROUND Detection of psychotic disorders is an important issue, since early treatment might improve prognosis. Timely diagnosis of psychotic disorders depends on recognition of psychotic symptoms and their interpretation. The aim of this study is to examine to what extent reported psychotic symptoms are accounted for in clinical diagnosis. METHODS The(More)
BACKGROUND Several factors may contribute to duration of untreated psychosis (DUP): patient-delay, referral-delay and treatment-delay caused by mental health care services (MHS-delay). In order to find the most effective interventions to reduce DUP, it is important to know what factors in these pathways to care contribute to DUP. AIM To examine the(More)
BACKGROUND Research into the risk factors for schizophrenia has once again drawn attention to the geographical differences in the incidence and gender distribution of schizophrenia. The incidence - as recorded by the mental health care services - of non-affective psychotic disorders in the Netherlands is unknown. AIM To ascertain the mental-health-care(More)
OBJECTIVE To examine the utility of the Community Assessment of Psychic Experiences (CAPE)-42, a self-report questionnaire, to improve detection of first-episode psychosis in new referrals to mental health services. METHOD At first contact with mental health-care services patients were asked to complete the CAPE-42 and were then routinely diagnosed by a(More)
OBJECTIVE Auditory hallucinations that are viewed by patients as positive and useful may be barriers to treatment-seeking. The aim was to assess prevalence, impact, and course of, and attributions to, these voices in psychotic and non-psychotic patients. METHOD One hundred thirty-one patients of a Voices Clinic and 65 members of the Dutch Resonance(More)
BACKGROUND Although there is evidence for the effectiveness of interventions for psychosis among ultra-high-risk (UHR) groups, health economic evaluations are lacking. This study aimed to determine the cost effectiveness and cost-utility of cognitive-behavioural therapy (CBT) to prevent first-episode psychosis. METHOD The Dutch Early Detection and(More)
BACKGROUND Previously, we demonstrated that cognitive behavior therapy for ultra-high risk (called CBTuhr) halved the incidence of psychosis over an 18-month period. Follow-up data from the same study are used to evaluate the longer-term effects at 4 years post-baseline. METHOD The Dutch Early Detection and Intervention Evaluation study was a randomized(More)
Background This study aims to evaluate the long-term cost-effectiveness of add-on cognitive behavior therapy (CBT) for the prevention of psychosis for individuals at ultrahigh risk (UHR) of psychosis. Method The Dutch Early Detection and Intervention randomized controlled trial was used, comparing routine care (RC; n = 101) with routine care plus CBT for(More)