Pieter J Hoekstra
Biographic Data
| ID | 5757525 |
|---|---|
| NAME | Pieter J Hoekstra |
| GIVEN NAMES | Pieter J |
| FAMILY NAME | Hoekstra |
| SIGNATURE | HOEKSTRA P J |
| AFFILIATIONS | University Medical Center Groningen |
| ORCID | 0000-0003-1018-9954 |
| VERIFIED | Yes |
| TOTAL WORKS | 17 |
| TOTAL CITATIONS | 1 |
| AUTHOR COUNT | 17 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 2012 |
| LATEST PUBLICATION YEAR | 2025 |
| H-INDEX | 1 |
Treatments with versus without medication for children with behavioural difficulties in clinical practice: An economic evaluation with observational data
BACKGROUND: Economic evaluations of treatments for children with behavioural difficulties (i.e., characteristics of attention-deficit/hyperactivity disorder (ADHD) and/or oppositional defiant disorder (ODD)) usually rely on data of randomised controlled trials or are model-based. Findings of such studies may not be representative of cost-effectiveness and cost-utility in clinical practice. The current longitudinal study aimed to perform an econom…
Research Review: Mechanisms of change and between‐family differences in parenting interventions for children with ADHD – an individual participant data meta‐analysis
BACKGROUND: Understanding the mechanisms of change and between-family differences in behavioural parenting interventions for children with attention-deficit/hyperactivity disorder (ADHD) may help personalise interventions. Therefore, we examined whether improvements in parenting are associated with changes in child behaviour and functional outcomes, and how these associations vary based on parents' baseline parenting levels. METHODS: We collected…
ADHD medication adherence reduces risk of committing minor offenses in adolescents
BACKGROUND: This study aimed to investigate the association between adolescents' adherence to attention-deficit/hyperactivity disorder (ADHD) medication and their risk of committing minor offenses. METHODS: Using two Dutch databases, Statistics Netherlands (CBS) and the Foundation for Pharmaceutical Statistics (SFK), we aimed to investigate the association between adherence to ADHD medication and registered minor offenses between 2005 and 2019 of…
Integrative Care for Challenging Behaviors in People with Intellectual Disabilities to Reduce Challenging Behaviors and Inappropriate Psychotropic Drug Prescribing Compared with Care as Usual: A Clust…
People with intellectual disabilities (IDs) often present with challenging behaviors (CBs) mostly due to inappropriate environments and mental and physical disorders. Integrative care is recommended to address CBs. However, in clinical practice, psychotropic drugs are often prescribed off-label for CBs, although the effectiveness is unclear, and side effects frequently occur. We conducted a cluster-randomized controlled study to investigate the e…
Commentary: Why treatment is the best choice for childhood mental disorders – a commentary on Roest et al. (2022)
An important question in mental healthcare for children is whether treatments are effective and safe in the long run. Here, we comment on a recent editorial perspective by Roest et al. (2022), who argue, based on an overview of systematic reviews, ‘that there is no convincing evidence that interventions for the most common childhood disorders are beneficial in the long term’. We believe that the available evidence does not justify this conclusion…
Difficulties in Addressing Diagnostic, Treatment and Support Needs in Individuals with Intellectual Disability and Persistent Challenging Behaviours: A Descriptive File Study of Referrals to an Expert…
Service providers may experience difficulties in providing appropriate care to optimize the functioning of individuals with intellectual disability and challenging behaviour. External consultation to identify and address the unmet support needs underlying the behaviour may be beneficial. Applying the multidimensional American Association Intellectual and Developmental Disabilities (AAIDD) model may facilitate this approach. We aimed to describe t…
Clinical precursors of tics: An Emtics study
BACKGROUND: Children with Tourette syndrome (TS) often have comorbid disorders, particularly attention-deficit/hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). While subtle premorbid symptoms have been described in various psychiatric disorders, the presence of clinical precursors that may exist before the onset of tics is unknown. This longitudinal study aimed to find clinical precursors of tics by assessing a range of clin…
Enhancing neuroimaging genetics through meta-analysis for Tourette syndrome (Enigma-TS): A worldwide platform for collaboration
Tourette syndrome (TS) is characterized by multiple motor and vocal tics, and high-comorbidity rates with other neuropsychiatric disorders. Obsessive compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), autism spectrum disorders (ASDs), major depressive disorder (MDD), and anxiety disorders (AXDs) are among the most prevalent TS comorbidities. To date, studies on TS brain structure and function have been limited in size wit…
Factors Related to Perceived Stigma in Parents of Children and Adolescents in Outpatient Mental Healthcare
Little is known about factors contributing to perceived stigma in parents of children and adolescents with behavioral and emotional problems in outpatient mental healthcare. We aimed to identify the most relevant factors related to perceived parental stigma using least absolute shrinkage and selection operator (LASSO) regression including a broad range of factors across six domains: (1) child characteristics, (2) characteristics of the primary pa…
The World Federation of ADHD International Consensus Statement: 208 Evidence-based conclusions about the disorder
BACKGROUND: Misconceptions about ADHD stigmatize affected people, reduce credibility of providers, and prevent/delay treatment. To challenge misconceptions, we curated findings with strong evidence base. METHODS: We reviewed studies with more than 2000 participants or meta-analyses from five or more studies or 2000 or more participants. We excluded meta-analyses that did not assess publication bias, except for meta-analyses of prevalence. For net…
Analysis of structural brain asymmetries in attention‐deficit/hyperactivity disorder in 39 datasets
OBJECTIVE: Some studies have suggested alterations of structural brain asymmetry in attention-deficit/hyperactivity disorder (ADHD), but findings have been contradictory and based on small samples. Here, we performed the largest ever analysis of brain left-right asymmetry in ADHD, using 39 datasets of the ENIGMA consortium. METHODS: We analyzed asymmetry of subcortical and cerebral cortical structures in up to 1,933 people with ADHD and 1,829 una…
Neurocognitive markers of late‐onset ADHD: A 6‐year longitudinal study
BACKGROUND: There is an increased interest in 'late-onset' attention-deficit/hyperactivity disorder (ADHD), referring to the onset of clinically significant ADHD symptoms after the age of 12 years. This study aimed to examine whether unaffected siblings with late-onset ADHD could be differentiated from stable unaffected siblings by their neurocognitive functioning in childhood. METHODS: We report findings from a 6-year prospective, longitudinal s…
Effects of methylphenidate on executive functioning in children and adolescents with ADHD after long‐term use: A randomized, placebo‐controlled discontinuation study
BACKGROUND: Methylphenidate may improve executive functioning in children with attention-deficit/hyperactivity disorder (ADHD). However, it is unclear if there are still acute effects of methylphenidate on executive functioning after long-term use. METHODS: In a randomized double-blind, placebo-controlled discontinuation study, 94 children and adolescents (ages 8-18 years) who used methylphenidate beyond two years were either assigned to seven we…
Yale Global Tic Severity Scale (YGTSS): Psychometric Quality of the Gold Standard for Tic Assessment Based on the Large-Scale Emtics Study
The Yale Global Tic Severity Scale (YGTSS) is a clinician-rated instrument considered as the gold standard for assessing tics in patients with Tourette's Syndrome and other tic disorders. Previous psychometric investigations of the YGTSS exhibit different limitations such as small sample sizes and insufficient methods. To overcome these shortcomings, we used a subsample of the large-scale "European Multicentre Tics in Children Study" (EMTICS) inc…
Mental and Social Health of Children and Adolescents With Pre-existing Mental or Somatic Problems During the Covid-19 Pandemic Lockdown
Background: The COVID-19 lockdown increases psychological problems in children and adolescents from the general population. Here we investigate the mental and social health during the COVID-19 lockdown in children and adolescents with pre-existing mental or somatic problems. Methods: We included participants (8-18 years) from a psychiatric ( N = 249) and pediatric ( N = 90) sample, and compared them to a general population sample ( N = 844). Meas…
The role of client empathy in treatment outcome in a sample of adolescents referred to forensic youth psychiatric services
Starting from the assumption that empathy is crucial in the therapeutic process, the current study explored whether client empathy before treatment relates to treatment outcome, whether client empathy is subject to change in the first six months of treatment, whether such change relates to treatment outcome and whether therapist factors relate to possible changes in client empathy. In total 90 adolescents treated by 31 therapists at forensic psyc…
Dopamine transporter gene moderates response to behavioral parent training in children with ADHD: A pilot study
There is great variability in the degree to which children with attention deficit/hyperactivity disorder (ADHD) improve through behavioral treatments. This study investigates the influence of the dopamine transporter gene (SCL6A3/DAT1) on outcome of behavioral parent training (BPT). Study subjects were a subsample (n = 50, for whom DAT1 genotypes were available) of a randomized controlled BPT effectiveness study (N = 94) comparing BPT plus ongoin…
Dopamine transporter gene moderates response to behavioral parent training in children with ADHD: A pilot study
There is great variability in the degree to which children with attention deficit/hyperactivity disorder (ADHD) improve through behavioral treatments. This study investigates the influence of the dopamine transporter gene (SCL6A3/DAT1) on outcome of behavioral parent training (BPT). Study subjects were a subsample (n = 50, for whom DAT1 genotypes were available) of a randomized controlled BPT effectiveness study (N = 94) comparing BPT plus ongoin…
Dopamine transporter gene moderates response to behavioral parent training in children with ADHD: A pilot study
There is great variability in the degree to which children with attention deficit/hyperactivity disorder (ADHD) improve through behavioral treatments. This study investigates the influence of the dopamine transporter gene (SCL6A3/DAT1) on outcome of behavioral parent training (BPT). Study subjects were a subsample (n = 50, for whom DAT1 genotypes were available) of a randomized controlled BPT effectiveness study (N = 94) comparing BPT plus ongoin…
The role of client empathy in treatment outcome in a sample of adolescents referred to forensic youth psychiatric services
Starting from the assumption that empathy is crucial in the therapeutic process, the current study explored whether client empathy before treatment relates to treatment outcome, whether client empathy is subject to change in the first six months of treatment, whether such change relates to treatment outcome and whether therapist factors relate to possible changes in client empathy. In total 90 adolescents treated by 31 therapists at forensic psyc…
The World Federation of ADHD International Consensus Statement: 208 Evidence-based conclusions about the disorder
BACKGROUND: Misconceptions about ADHD stigmatize affected people, reduce credibility of providers, and prevent/delay treatment. To challenge misconceptions, we curated findings with strong evidence base. METHODS: We reviewed studies with more than 2000 participants or meta-analyses from five or more studies or 2000 or more participants. We excluded meta-analyses that did not assess publication bias, except for meta-analyses of prevalence. For net…
Analysis of structural brain asymmetries in attention‐deficit/hyperactivity disorder in 39 datasets
OBJECTIVE: Some studies have suggested alterations of structural brain asymmetry in attention-deficit/hyperactivity disorder (ADHD), but findings have been contradictory and based on small samples. Here, we performed the largest ever analysis of brain left-right asymmetry in ADHD, using 39 datasets of the ENIGMA consortium. METHODS: We analyzed asymmetry of subcortical and cerebral cortical structures in up to 1,933 people with ADHD and 1,829 una…
Neurocognitive markers of late‐onset ADHD: A 6‐year longitudinal study
BACKGROUND: There is an increased interest in 'late-onset' attention-deficit/hyperactivity disorder (ADHD), referring to the onset of clinically significant ADHD symptoms after the age of 12 years. This study aimed to examine whether unaffected siblings with late-onset ADHD could be differentiated from stable unaffected siblings by their neurocognitive functioning in childhood. METHODS: We report findings from a 6-year prospective, longitudinal s…
Effects of methylphenidate on executive functioning in children and adolescents with ADHD after long‐term use: A randomized, placebo‐controlled discontinuation study
BACKGROUND: Methylphenidate may improve executive functioning in children with attention-deficit/hyperactivity disorder (ADHD). However, it is unclear if there are still acute effects of methylphenidate on executive functioning after long-term use. METHODS: In a randomized double-blind, placebo-controlled discontinuation study, 94 children and adolescents (ages 8-18 years) who used methylphenidate beyond two years were either assigned to seven we…
Yale Global Tic Severity Scale (YGTSS): Psychometric Quality of the Gold Standard for Tic Assessment Based on the Large-Scale Emtics Study
The Yale Global Tic Severity Scale (YGTSS) is a clinician-rated instrument considered as the gold standard for assessing tics in patients with Tourette's Syndrome and other tic disorders. Previous psychometric investigations of the YGTSS exhibit different limitations such as small sample sizes and insufficient methods. To overcome these shortcomings, we used a subsample of the large-scale "European Multicentre Tics in Children Study" (EMTICS) inc…
Mental and Social Health of Children and Adolescents With Pre-existing Mental or Somatic Problems During the Covid-19 Pandemic Lockdown
Background: The COVID-19 lockdown increases psychological problems in children and adolescents from the general population. Here we investigate the mental and social health during the COVID-19 lockdown in children and adolescents with pre-existing mental or somatic problems. Methods: We included participants (8-18 years) from a psychiatric ( N = 249) and pediatric ( N = 90) sample, and compared them to a general population sample ( N = 844). Meas…
Clinical precursors of tics: An Emtics study
BACKGROUND: Children with Tourette syndrome (TS) often have comorbid disorders, particularly attention-deficit/hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). While subtle premorbid symptoms have been described in various psychiatric disorders, the presence of clinical precursors that may exist before the onset of tics is unknown. This longitudinal study aimed to find clinical precursors of tics by assessing a range of clin…
Enhancing neuroimaging genetics through meta-analysis for Tourette syndrome (Enigma-TS): A worldwide platform for collaboration
Tourette syndrome (TS) is characterized by multiple motor and vocal tics, and high-comorbidity rates with other neuropsychiatric disorders. Obsessive compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), autism spectrum disorders (ASDs), major depressive disorder (MDD), and anxiety disorders (AXDs) are among the most prevalent TS comorbidities. To date, studies on TS brain structure and function have been limited in size wit…
Factors Related to Perceived Stigma in Parents of Children and Adolescents in Outpatient Mental Healthcare
Little is known about factors contributing to perceived stigma in parents of children and adolescents with behavioral and emotional problems in outpatient mental healthcare. We aimed to identify the most relevant factors related to perceived parental stigma using least absolute shrinkage and selection operator (LASSO) regression including a broad range of factors across six domains: (1) child characteristics, (2) characteristics of the primary pa…
Commentary: Why treatment is the best choice for childhood mental disorders – a commentary on Roest et al. (2022)
An important question in mental healthcare for children is whether treatments are effective and safe in the long run. Here, we comment on a recent editorial perspective by Roest et al. (2022), who argue, based on an overview of systematic reviews, ‘that there is no convincing evidence that interventions for the most common childhood disorders are beneficial in the long term’. We believe that the available evidence does not justify this conclusion…
Difficulties in Addressing Diagnostic, Treatment and Support Needs in Individuals with Intellectual Disability and Persistent Challenging Behaviours: A Descriptive File Study of Referrals to an Expert…
Service providers may experience difficulties in providing appropriate care to optimize the functioning of individuals with intellectual disability and challenging behaviour. External consultation to identify and address the unmet support needs underlying the behaviour may be beneficial. Applying the multidimensional American Association Intellectual and Developmental Disabilities (AAIDD) model may facilitate this approach. We aimed to describe t…
ADHD medication adherence reduces risk of committing minor offenses in adolescents
BACKGROUND: This study aimed to investigate the association between adolescents' adherence to attention-deficit/hyperactivity disorder (ADHD) medication and their risk of committing minor offenses. METHODS: Using two Dutch databases, Statistics Netherlands (CBS) and the Foundation for Pharmaceutical Statistics (SFK), we aimed to investigate the association between adherence to ADHD medication and registered minor offenses between 2005 and 2019 of…
Integrative Care for Challenging Behaviors in People with Intellectual Disabilities to Reduce Challenging Behaviors and Inappropriate Psychotropic Drug Prescribing Compared with Care as Usual: A Clust…
People with intellectual disabilities (IDs) often present with challenging behaviors (CBs) mostly due to inappropriate environments and mental and physical disorders. Integrative care is recommended to address CBs. However, in clinical practice, psychotropic drugs are often prescribed off-label for CBs, although the effectiveness is unclear, and side effects frequently occur. We conducted a cluster-randomized controlled study to investigate the e…
Treatments with versus without medication for children with behavioural difficulties in clinical practice: An economic evaluation with observational data
BACKGROUND: Economic evaluations of treatments for children with behavioural difficulties (i.e., characteristics of attention-deficit/hyperactivity disorder (ADHD) and/or oppositional defiant disorder (ODD)) usually rely on data of randomised controlled trials or are model-based. Findings of such studies may not be representative of cost-effectiveness and cost-utility in clinical practice. The current longitudinal study aimed to perform an econom…
Research Review: Mechanisms of change and between‐family differences in parenting interventions for children with ADHD – an individual participant data meta‐analysis
BACKGROUND: Understanding the mechanisms of change and between-family differences in behavioural parenting interventions for children with attention-deficit/hyperactivity disorder (ADHD) may help personalise interventions. Therefore, we examined whether improvements in parenting are associated with changes in child behaviour and functional outcomes, and how these associations vary based on parents' baseline parenting levels. METHODS: We collected…
Psychology (16 works) · Psychiatry (15 works) · Clinical Psychology (14 works) · Medicine (13 works) · Attention Deficit Hyperactivity Disorder (10 works) · Clinical Psychology (8 works) · Cognition (5 works) · Developmental psychology (5 works) · Autism Spectrum Disorder Research (4 works) · Child and Adolescent Psychosocial and Emotional Development (4 works)