Associations of attention-deficit/hyperactivity and other childhood disorders with psychotic experiences and disorders in adolescence

Loneliness and susceptibility to social pain mediate the association between autistic traits and psychotic experiences in young non-clinical adults

Understanding of the mechanisms involved in the occurrence of psychotic experiences (PEs) in highly autistic individuals is crucial for identifying appropriate prevention and intervention strategies. This study aimed to investigate the mediating role of susceptibility to social pain and loneliness in the relationship between autistic traits (ATs) and PEs in adults from the general population of 12 Arab countries. This cross-sectional study is part of a large-scale multi-country research project. A total of 7646 young adults (age range 18-35 years, mean age of 22.55 ± 4.00 years and 75.5% females) from twelve Arab countries (i.e., Algeria, Bahrain, Egypt, Iraq, Jordan, Kingdom of Saudi Arabia, Kuwait, Lebanon, Morocco, Oman, Palestine, and Tunisia) were included. Mediation analyses showed that, after adjusting over confounding variables, both loneliness (indirect effect: Beta = 0.18; Boot SE = 0.02; Boot CI 0.14; 0.21) and social pain (indirect effect: Beta = 0.03; Boot SE = 0.01; Boot CI 0.001; 0.05) partially mediated the association between ATs and PEs. Higher ATs were significantly associated with more loneliness and susceptibility to social pain, and directly associated with more severe PEs. Finally, higher loneliness and susceptibility to social pain were significantly associated with greater PEs scores. Findings indicated that individuals with higher ATs tend to experience greater loneliness and feel more pain from rejection, which can in turn be associated with higher levels of PEs. Interventions targeting susceptibility to social pain and loneliness as a means of mitigating PEs among highly autistic adults should be considered.

The Association between Attention-Deficit-Hyperactivity Disorder and Autistic Traits with Psychotic-like Experiences in Sample of Youths Who Were Referred to a Psychiatric Outpatient Service

The aim of this study is to identify autism spectrum disorder (ASD) and attention-deficit-hyperactivity disorder (ADHD) traits in adolescents who experience psychotic-like experiences (PLEs), often ignored in clinical practice but widely prevalent in the general population. A total of 57 adolescents and young adults (aged between 16 and 24 years old) were recruited consecutively in the outpatient services. A total of 37 were females (64.9%), 18 were males (31.6%), and two participants (3.5%) were non-binary or gender non-conforming, with a mean age at referral of 18.26 ± 2.06. To investigate these symptoms, three sets of standardized questionnaires were used, as follows: the Autism Spectrum Quotient-short form (AQ-10), the Community Assessment of Psychic Experiences (CAPE-42), and the Adult ADHD Self-Report Scale (ASRS). We found significant associations between the ASRS and AQ-10 total scores and all CAPE scales. The model which explained the highest variance was CAPE Score's Total Frequency score (p < 0.001). Our findings underline the importance of investigating the presence of subthreshold ASD and ADHD symptoms in clinical populations, particularly in the period of adolescence and young adulthood, to promptly identify the presence of PLEs and, thus, prevent the onset of a frank psychotic disorder, particularly in the presence of a comorbid psychopathological condition, leading to better diagnosis and treatment for individuals with two or more of these conditions.

Understanding psychotic-like experiences in children in the context of dimensions of psychological problems

Introduction

Although psychotic behaviors can be difficult to assess in children, early identification of children at high risk for the emergence of psychotic symptoms may facilitate the prevention of related disorders. Psychotic-like experiences (PLEs), or subthreshold thought and perceptual disturbances, could be early manifestations of psychosis that may predict a future diagnosis of a psychosis-related disorder or nonspecific correlates of a wide range of psychological problems. Additional research is needed regarding how PLEs map onto dimensions of psychopathology in children.

Methods

In the present study, we examined the association between PLEs and general and specific dimensions of psychological problems in a sample of 10,692 children from the Adolescent Brain Cognitive Development Study (ABCD Study).

Results

The results of this study showed that self-reported PLEs were associated with a general psychopathology factor and an ADHD factor, which were defined in hierarchical models of parent-rated psychological problems.

Discussion

These findings suggest that PLEs are broadly associated with a wide range of psychological problems through the general psychopathology factor even before psychotic disorders typically manifest. This study supports the need for longitudinal analyses of future waves of the ABCD Study to determine if PLEs can detect children at high risk for serious psychological problems in adulthood.

Effects of Psychiatric Comorbidities on the Prognosis of New-Onset Pediatric Epilepsy: A Retrospective Nationwide Cohort Study

Background/Objectives: To determine the impact of psychiatric disorders on epilepsy treatment outcomes and healthcare utilization in children with epilepsy (CWE) based on the presence or timing of the onset of psychiatric disorders. Methods: This retrospective controlled study enrolled children (age < 18 years) with newly diagnosed epilepsy into four groups stratified by the presence and timing of the onset of psychiatric disorders (None: no psychiatric disorders; Before: psychiatric disorders only preceding the epilepsy diagnosis; After: new psychiatric disorders diagnosed only after the epilepsy diagnosis; Mixed: different psychiatric disorders diagnosed both before and after epilepsy diagnosis) and compared the intergroup differences in epilepsy treatment outcomes and healthcare utilization. Results: Among the CWE (n = 37,678), 13,285 (35.26%) had comorbid psychiatric disorders. The After (n = 7892), Mixed (n = 3105), and Before (n = 2288) groups had significantly longer treatment periods than those in the None group (p < 0.001). Compared with the None group, the remaining groups had significantly higher frequencies of outpatient visits, emergency room visits, and admissions and higher rates of status epilepticus and drug-resistant epilepsy (p < 0.001, respectively), with higher odds ratios [95% confidence interval] for status epilepticus (2.92 [2.68-3.18]) and drug-resistant epilepsy (3.01 [2.85-3.17]) in the After group. Conclusions: Psychiatric comorbidities, diagnosed before and after epilepsy diagnosis, negatively affected the treatment outcomes. CWE without prior psychiatric disorders that were newly diagnosed during epilepsy treatment had the worst outcomes and the highest healthcare utilization rates.

Are attention-deficit/hyperactivity disorder symptoms associated with negative health outcomes in individuals with psychotic experiences? Findings from a cross-sectional study in Japan

Objective

Although research has indicated that the prevalence of attention-deficit/hyperactivity disorder (ADHD) may be elevated in individuals with psychotic disorders, as yet, there has been comparatively little research on this association and its effects among adults at the subclinical level. To address this deficit, the current study examined the association between psychotic experiences (PE) and ADHD symptoms in Japanese individuals and whether the presence of ADHD symptoms increases the risk for negative health outcomes in people with PE.

Method

Data were analyzed from an online sample of 1,452 individuals (age 18-89; 51.5% female) collected in 2021. Information on PE was obtained with the PRIME Screen-Revised (PS-R), while the Adult ADHD Self-Report Scale (ASRS) Screener was used to measure ADHD symptoms. Information was also obtained on a number of health outcomes including anxiety and depressive symptoms and suicidal ideation. Logistic regression was used to assess associations.

Results

In a fully adjusted analysis PE were associated with almost three times higher odds for ADHD symptoms (OR: 2.92, 95%CI: 1.19-7.17). In an analysis that was restricted to individuals with PE, ADHD symptoms were associated with significantly increased odds for depressive symptoms, lifetime suicidal ideation, perceived stress and severe sleep problems.

Conclusion

ADHD symptoms are present in some individuals with PE and increase the odds for several detrimental health outcomes in this population. Identifying co-occurring PE and ADHD/ADHD symptoms may facilitate treatment options and help prevent negative health outcomes in individuals with these conditions.

Transition care for adolescents and young adults with attention-deficit hyperactivity disorder (ADHD): A descriptive summary of qualitative evidence

The review presents a summary of available evidence about transition care of ADHD patients from all service users' perspectives. Common barriers, and suggestions for improvement ADHD of transition care, were extrapolated from qualitative research, including case notes studies, and were exposed. A comprehensive search of the PubMed, Embase, PsychInfo and Web of Science databases for articles published up to October 2021 was conducted to summarize recent evidence on the experiences of all stakeholders involved in the transition process. Reviews, other chronic conditions and different meaning of transition were excluded. Authors extracted data and assessed study quality independently. Findings were discussed taking into consideration barriers and suggestions from all service users' perspectives. Findings from 23 studies with different context and methods were collected and summarized. Most of the studies were conducted in UK, using interviews and questionnaires, and addressed to the physicians. The lack of information about ADHD as a condition and about transition process were the barriers most reported, while joint working and sharing transition protocols were the suggestions pointed out by all stakeholders. Despite different perspectives, all stakeholders exposed similar needs. The review reveals an evident need for defining and evaluating the effectiveness of transition programmes from child to adult ADHD services.

ADHD in Adults: A Systematic Review and Meta-Analysis of Prevalence Studies in Outpatient Psychiatric Clinics

OBJECTIVE

Systematic review and meta-analysis to estimate the pooled prevalence of ADHD in adult attendees of outpatient mental health clinics and to investigate factors influencing prevalence rates.

METHODS

The following were extracted: demographics, design of the study (screening only or two-phase), scales/criteria for diagnosis of ADHD, number of ADHD, and non-ADHD participants.

RESULTS

The pooled prevalence of ADHD from screening studies (n = 9) was 26.7%, (95% CI [17.2-37.4]), ADHD = 1727, No ADHD = 3,578. From studies employing a two-stage design (n = 5), prevalence was 14.61%, CI [10.39-19.41], ADHD = 561, No ADHD = 3,578. Age and gender did not have any significant effect on the estimated prevalence. By contrast exclusion of psychotic disorders lowers prevalence. The screening scale used also influence prevalence rates.

CONCLUSION

Meta-analysis shows high rates of adult ADHD among psychiatric outpatient clinics. Applying DSM-5 criteria increased prevalence rates. More methodologically robust studies, using two-stage design, need to be conducted to help assist in service planning.

Prescription Stimulants in College and Medical Students: A Narrative Review of Misuse, Cognitive Impact, and Adverse Effects

Stimulants are effective in treating attention-deficit/hyperactivity disorder (ADHD). Psychiatrist Charles Bradley first made this discovery in 1937 when he found that children treated with amphetamines showed improvements in school performance and behavior. Between 1995 and 2008, stimulants to treat ADHD increased six-fold among American adults and adolescents at an annual rate of 6.5%. Stimulants without a prescription, known as nonmedical use or misuse, have also increased. The highest rates of nonmedical prescription drug misuse in the United States are seen most notably in young adults between 18 and 25 years, based on data from the Substance Abuse and Mental Health Services Administration in 2021. Aside from undergraduate students, nonmedical prescription stimulant use is prevalent among medical students worldwide. A recent literature review reported the utilization of stimulants without a prescription in 970 out of 11,029 medical students. The percentages of medical students across the country misusing stimulants varied from 5.2% to 47.4%. Academic enhancement, reported in 50% to 89% of college students with stimulant misuse, is the most common reason for nonmedical stimulant use. With the increasing use of stimulants among adolescents and adults, it is unclear what long-term outcomes will be since little data are available that describe differences in how side effects are experienced for prescribed and non-prescribed users. The present narrative review focuses on these adverse effects in this population and the reasonings behind misuse and nonmedical use.

Children with Attention-Deficit/Hyperactivity Disorder Grown Up: An 18-Year Follow-Up after Multimodal Treatment

OBJECTIVE

ADHD treatment has positive effects on behavioral symptoms and psychosocial functioning, but studies that follow children treated for ADHD into adulthood are rare.

METHOD

This follow-up study assessed symptom severity and functional outcomes of adults (n = 70) who had received individualized ADHD treatment in the Cologne Adaptive Multimodal Treatment (CAMT) Study at ages 6 to 10 years.

RESULTS

Despite symptomatic improvement, participants reported poorer educational and occupational outcomes than expected (e.g., currently unemployed: 17%). They had also been in contact with the justice system more often than expected (e.g., lifetime convictions: 33%) and were impaired on health-related outcomes (e.g., substance use problems: 15%). Several social outcomes were favorable (e.g., long-term relationship/married: 63%).

CONCLUSION

Compared to the general population or norm samples, CAMT participants had a higher relative risk (RR) of functional impairments, demonstrating the need for continued support for a substantial proportion of the young adults.

Peer-reported bullying, rejection and hallucinatory experiences in childhood

OBJECTIVE

Psychotic experiences, such as hallucinations, occur commonly in children and have been related to bullying victimization. However, whether bullying perpetration, peer rejection, or peer acceptance are related to hallucinatory experiences has remained under-examined. We used a novel peer nomination method to examine whether (i) bullying perpetration and (ii) social positions within peer networks were associated with future hallucinatory experiences.

METHODS

This prospective study was embedded in the population-based Generation R Study. Bullying perpetration, peer rejection, and peer acceptance were assessed using peer nominations at age 7 years (N = 925). Using a social network analysis, we estimated social positions within peer rejection and acceptance networks. Bullying victimization was assessed using self-reports. Self-reported hallucinatory experiences were assessed at age 10 years. Analyses were adjusted for sociodemographic covariates.

RESULTS

Higher levels of bullying perpetration were prospectively associated with an increased burden of hallucinatory experiences (OR = 1.22, 95% CI 1.05-1.43, p = 0.011). Bullies had a 50% higher, and bully-victims had a 89% higher odds, of endorsing hallucinatory experiences three years later than children who were not involved in bullying (OR_bully = 1.50, 95% CI 1.01-2.24, p = 0.045; OR_bully-victim = 1.89, 95% CI 1.15-3.10, p = 0.012). Unfavorable positions within peer rejection networks, but not peer acceptance networks, were associated with an increased risk for hallucinatory experiences (OR_{peer rejection} = 1.24, 95% CI 1.07-1.44, p_{FDR-corrected} = 0.024).

CONCLUSION

Using peer reports, we observed that bullies and socially rejected children have a higher likelihood to report hallucinatory experiences in pre-adolescence. Children who are both a bully and a victim of bullying (ie, bully-victims) may be particularly vulnerable for psychotic experiences.

[ADHD during childhood and subsequent psychotic disorder: A link?]

OBJECTIVES

Attention Deficit with/without Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder with frequent comorbid psychiatric disorders. Several studies have underlined the increased risk of developing a psychotic disorder subsequent to a childhood ADHD. The aim of our review is not only to clarify this association and the related physiopathology but also to understand the consequences for therapeutic management.

METHODS

We processed a narrative review of available literature based on a research of the PubMed database. Articles related to ADHD and psychotic disorder on a genetical, clinical or biological level were selected by one of the authors.

RESULTS

ADHD and psychotic disorders share neonatal, environmental, and genetic risk factors. On a neurobiological level, both disorders are concerned by a dysfunction of the dopaminergic system with an abnormal regulation of dopaminergic neurons' phasic and tonic activity. Our review aims to explain the « dynamic » model of dopaminergic dysfunctions and propose some guidance for pharmacological treatment of ADHD, with or without psychotic disorder. This model offers a better understanding of why methylphenidate is not associated to an increased risk of psychotic disorder and could act as a protective factor. Association between ADHD and psychotic disorders could be explained by some comorbidities such as substance use disorders which are frequently associated with both conditions and could act as mediator in the genesis of psychotic disorders following ADHD during childhood. Our review also focuses on an epidemiological bias that could be found in some studies such as possible diagnostic errors, as some non-specific clinical signs could be found in both late diagnosed ADHD and in "at risk mental state" of psychosis.

CONCLUSION

ADHD and psychotic disorders share common risk factors, neurobiological pathways and clinical symptoms. Perspectives for future studies are proposed considering a dimensional aspect of psychiatric disorders using, for example, Research Domain Criteria and exploring the link between the two conditions.

Association of Attention-Deficit/Hyperactivity Disorder in Childhood and Adolescence With the Risk of Subsequent Psychotic Disorder: A Systematic Review and Meta-analysis

Importance

Growing evidence supports an association between attention-deficit/hyperactivity disorder (ADHD) in childhood and subsequent psychotic disorders. Both disorders share physiopathological features such as attention deficits, dopaminergic imbalance, and genetic susceptibility. However, the results of epidemiologic studies have been conflicting.

Objective

To provide a quantitative synthesis of studies exploring the association between ADHD and the risk of subsequent psychotic disorder.

Data Sources

A systematic literature search of the MEDLINE, Scopus, PsycInfo, and Web of Science databases was performed from inception until the final analysis on July 7, 2020. No restriction of language was applied.

Study Selection

Cohort and case-control studies examining the relative risk of developing a psychotic disorder in people diagnosed with ADHD at younger than 18 years compared with control individuals without ADHD.

Data Extraction and Synthesis

Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed in reporting results. Two independent reviewers extracted the data and assessed the risk of bias of individual studies using the Newcastle-Ottawa Scale. Preferably adjusted odds ratios (aORs) or hazard ratios from the identified studies were extracted, and ORs were computed when they were not adjusted. A random-effects model was used to calculate the pooled relative effect using the meta package in R.

Main Outcomes and Measures

An association between ADHD (exposure) and psychotic disorder (outcomes); both diagnoses were based on international classification.

Results

A total of 15 studies were included in the review. Twelve studies were pooled in the meta-analysis, representing 1.85 million participants. A diagnosis of ADHD in childhood was associated with a significant increase in the risk of subsequent psychotic disorder, with a pooled relative effect of 4.74 (95% CI, 4.11-5.46; I2 = 43% [95% CI, 0%-70%]). No significant between-group differences were found for subgroup analyses according to psychotic disorder (odds ratio [OR], 5.04; 95% CI, 4.36-5.83) or schizophrenia (OR, 4.59; 95% CI, 3.83-5.50) outcomes, cohort (OR, 4.64; 95% CI, 4.04-5.34) or case-control (OR, 6.81; 95% CI, 4.21-11.03) study design, and adjusted (OR, 4.72; 95% CI, 4.11-5.46) or unadjusted (OR, 3.81; 95% CI, 1.39-10.49) estimates. Meta-regressions were not significant when sex and bias score were used as covariates. No evidence of publication bias was found.

Conclusions and Relevance

These findings suggest that childhood ADHD is associated with an increased risk of a subsequent psychotic disorder. Further studies are required to determine the mechanisms linking these common conditions and whether early intervention for ADHD might reduce the risk of subsequent psychotic disorder.

Psychotic experiences and future school performance in childhood: a population-based cohort study

BACKGROUND

Psychotic experiences are common in childhood and an important risk indicator of adverse mental health outcomes. However, little is known about the association of psychotic experiences with functional outcomes in childhood, particularly regarding school performance. The aim of the present study was to examine whether psychotic experiences were prospectively related to school performance in childhood.

METHODS

This study was embedded in the population-based Generation R Study (N = 2,362). Psychotic experiences were assessed using self-reports on hallucinations at age 10 years. School performance was assessed using a standardized national school performance test at age 12 years. We considered the total school performance score, as well as language and mathematics subscales. Analyses were adjusted for sociodemographic characteristics, maternal nonverbal IQ, nonverbal IQ at age 6 years and co-occurring psychopathology at age 10 years.

RESULTS

Psychotic experiences were prospectively associated with poorer school performance scores (B = -0.61, 95% CI [-0.98;-0.25], p = .001), as well as poorer language (B_{percentile rank score}  = -2.00, 95% CI [-3.20;-0.79], p = .001) and mathematical ability (B_{percentile rank score}  = -1.75, 95% CI [-2.99;-0.51], p = .006). These associations remained after additional adjustment for nonverbal IQ at age 6 years (B = -0.51, 95% CI [-0.86;-0.16], p = .005), and co-occurring internalizing (B = -0.40, 95% CI [-0.77;-0.03], p = .036) and externalizing problems (B = -0.40, 95% CI [-0.75;-0.04], p = .029), but not attention problems (B = -0.10, 95% CI [-0.47;0.26], p = .57).

CONCLUSIONS

Children with psychotic experiences had lower school performance scores than their nonaffected peers. The finding was independent of sociodemographic characteristics, intelligence and co-occurring internalizing and externalizing problems, but not attention problems. This study suggests that psychotic experiences are associated with childhood functional impairments, although the relatively small effects and the role of attention problems warrant further exploration.

Psychotic experiences in seven-year-old children with familial high risk of schizophrenia or bipolar disorder in: The Danish High Risk and Resilience Study - VIA 7; A population-based cohort study

We aimed to examine the prevalence of psychotic experiences (PEs) in children with familial high risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP) and, in exploratory analyses, to examine the possible associations between PEs and mental disorders as well as level of functioning. A cohort of seven-year-old children with FHR-SZ (N = 199), FHR-BP (N = 118) and controls (N = 196) was recruited through Danish nationwide registers. Lifetime PEs were assessed through interviews using the psychosis section of the 'Schedule for Affective Disorders and Schizophrenia for School-Age Children - Present and Lifetime Version' (K-SADS-PL). Lifetime DSM-IV diagnoses were ascertained through K-SADS-PL and the level of functioning of the children through 'Children's Global Assessment Scale'. Both children with FHR-SZ (OR = 2.9, 95% CI = 1.4-6.2, p = 0.005) and FHR-BP (OR = 2.9, 95% CI = 1.3-6.7, p = 0.011) had an increased risk of having experienced "severe" PEs compared with controls. In the overall cohort PEs were associated with any lifetime mental disorder, Attention-Deficit/Hyperactivity Disorder, anxiety disorders and a lower level of functioning. The findings of a higher proportion of high risk children reporting PEs could represent an early manifestation of later more severe psychopathology or simply an unspecific transitory symptom. Future follow-up studies of this cohort will explore the predictive value of the occurrence of PEs at age seven.

Terminology and assessment tools of psychosis: A systematic narrative review

AIM

Phenomena within the psychosis continuum that varies in frequency/duration/intensity have been increasingly identified. Different terms describe these phenomena, however there is no standardization within the terminology. This review evaluated the definitions and assessment tools of seven terms - (i) 'psychotic experiences'; (ii) 'psychotic-like experiences'; (iii) 'psychotic-like symptoms'; (iv) 'attenuated psychotic symptoms'; (v) 'prodromal psychotic symptoms'; (vi) 'psychotic symptomatology'; and (vii) 'psychotic symptoms'.

METHODS

EMBASE, MEDLINE, and CINAHL were searched during February-March 2019. Inclusion criteria included 1989-2019, full text, human, and English. Papers with no explicit definition or assessment tool, duplicates, conference abstracts, systematic reviews, meta-analyses, or no access were excluded.

RESULTS

A total of 2238 papers were identified and of these, 627 were included. Definitions and assessment tools varied, but some trends were found. Psychotic experiences and psychotic-like experiences were transient and mild, found in the general population and those at-risk. Psychotic-like symptoms were subthreshold and among at-risk populations and non-psychotic mental disorders. Attenuated psychotic symptoms were subthreshold but associated with distress, risk, and help-seeking. Prodromal psychotic symptoms referred to the prodrome of psychotic disorders. Psychotic symptomatology included delusions and hallucinations within psychotic disorders. Psychotic symptoms was the broadest term, encompassing a range of populations but most commonly involving hallucinations, delusions, thought disorder, and disorganization.

DISCUSSION

A model for conceptualizing the required terms is proposed and future directions needed to advance this field of research are discussed.

Attention Deficit/Hyperactivity Disorder and risk for non-affective psychotic disorder: The role of ADHD medication and comorbidity, and sibling comparison

Attention Deficit/Hyperactivity Disorder (ADHD) is the most common psychiatric disorder in childhood. It is unclear whether ADHD increases the risk of non-affective psychotic disorder (NAPD). The study included a matched cohort, drawn from all born in Sweden 1987-1991 (n = 548,852). ADHD was defined as ICD diagnosis and/or prescription of ADHD medication. We distinguished between stimulants and non-stimulants, and usage duration (<1 year, 1-2 years and ≥2 years). We calculated odds ratios (OR) with 95% confidence intervals (CI) for NAPD, adjusted for confounders, comorbid autism spectrum disorder (ASD) and substance abuse. ADHD cases were also compared to their unaffected full siblings. We analyzed 18,139 ADHD cases and 72,437 sex and birth year matched controls. NAPD was more common in cases than controls (2.7 and 0.4%, respectively). After adjustment for confounders, ADHD cases had markedly high risk for NAPD (OR: 6.99; 95% CI 6.03-8.10), which attenuated further after adjustment for ASD and substance abuse (OR: 2.57; 95% CI 2.09-3.16). Utilization of ADHD medication increased the risk for NAPD (ORs for change in odds of NAPD for every 5 extra prescriptions of stimulants 1.06 (95% CI 1.02-1.10) and, non-stimulants 1.15 (95% CI 1.01-1.30)). There was no association between usage length of medication and risk for NAPD. The risk was higher in individuals with ADHD than their unaffected siblings (OR: 2.95 (95% CI 2.07-4.20)). Overall, ADHD was associated with elevated risk for NAPD, which is not entirely explained by shared familial factors. The clinical severity leading to medical treatment may also increase NAPD risk. Ethics approval: Approved by the ethical committee in Stockholm, Sweden (dnrs: 2010-1185-31/5 and 2013/1118-32).

Neurological and psychiatric adverse effects of long-term methylphenidate treatment in ADHD: A map of the current evidence

Methylphenidate (MPH), the most common medication for children with Attention Deficit/Hyperactivity Disorder (ADHD) in many countries, is often prescribed for long periods of time. Any long-term psychotropic treatment in childhood raises concerns about possible adverse neurological and psychiatric outcomes. We aimed to map current evidence regarding neurological and psychiatric outcomes, adverse or beneficial, of long-term MPH (> 1 year) treatment in ADHD. We coded studies using a "traffic light" system: Green: safe/favours MPH; Amber: warrants caution; Red: not safe/not well-tolerated. Un-categorisable study findings were coded as "Unclear". Although some evidence suggests an elevated risk of psychosis and tics, case reports describe remission on discontinuation. Several studies suggest that long-term MPH may reduce depression and suicide in ADHD. Evidence suggests caution in specific groups including pre-school children, those with tics, and adolescents at risk for substance misuse. We identified a need for more studies that make use of large longitudinal databases, focus on specific neuropsychiatric outcomes, and compare outcomes from long-term MPH treatment with outcomes following shorter or no pharmacological intervention.

Young spontaneously hypertensive rats (SHRs) display prodromal schizophrenia-like behavioral abnormalities

The Spontaneously Hypertensive Rat (SHR) strain has been suggested as an animal model of schizophrenia, considering that adult SHRs display behavioral abnormalities that mimic the cognitive, psychotic and negative symptoms of the disease and are characteristic of its animal models. SHRs display: (I) deficits in fear conditioning and latent inhibition (modeling cognitive impairments), (II) deficit in prepulse inhibition of startle reflex (reflecting a deficit in sensorimotor gating, and associated with psychotic symptoms), (III) diminished social behavior (modeling negative symptoms) and (IV) hyperlocomotion (modeling the hyperactivity of the dopaminergic mesolimbic system/ psychotic symptoms). These behavioral abnormalities are reversed specifically by the administration of antipsychotic drugs. Here, we performed a behavioral characterization of young (27-50 days old) SHRs in order to investigate potential early behavioral abnormalities resembling the prodromal phase of schizophrenia. When compared to Wistar rats, young SHRs did not display hyperlocomotion or PPI deficit, but exhibited diminished social interaction and impaired fear conditioning and latent inhibition. These findings are in accordance with the clinical course of schizophrenia: manifestation of social and cognitive impairments and absence of full-blown psychotic symptoms in the prodromal phase. The present data reinforce the SHR strain as a model of schizophrenia, expanding its validity to the prodromal phase of the disorder.

α4βδ GABAA Receptors Trigger Synaptic Pruning and Reduce Dendritic Length of Female Mouse CA3 Hippocampal Pyramidal Cells at Puberty

Synaptic pruning during adolescence is critical for optimal cognition. The CA3 hippocampus contains unique spine types and plays a pivotal role in pattern separation and seizure generation, where sex differences exist, but adolescent pruning has only been studied in the male. Thus, for the present study we assessed pruning of specific spine types in the CA3 hippocampus during adolescence and investigated a possible mechanism in the female mouse. To this end, we used Golgi-impregnated brains from pubertal (∼PND 35, assessed by vaginal opening) and post-pubertal (PND 56) mice. Spine density was assessed from z-stack (0.1-μm steps) images taken using a Nikon DS-U3 camera through a Nikon Eclipse Ci-L microscope and analyzed with NIS Elements. Spine density decreased significantly (P < 0.05) during adolescence, with 50-60% decreases in mushroom and stubby spine-types (P < 0.05, ∼PND35 vs. PND56) in non-proestrous mice. This was associated with decreases in kalirin-7, a spine protein which stabilizes the cytoskeleton and is required for spine maintenance. Because our previous findings suggest that pubertal increases in α4βδ GABAA receptors (GABARs) trigger pruning in CA1, we investigated their role in CA3. α4 expression in CA3 hippocampus increased 4-fold at puberty (P < 0.05), assessed by immunostaining and verified electrophysiologically by an increased response to gaboxadol (100 nM), which is selective for α4βδ. Knock-out of α4 prevented the pubertal decrease in kalirin-7 and synaptic pruning and also increased the dendritic length, demonstrating a functional link. These data suggest that pubertal α4βδ GABARs alter dendritic morphology and trigger pruning in female CA3 hippocampus.

Cannabidiol Administered During Peri-Adolescence Prevents Behavioral Abnormalities in an Animal Model of Schizophrenia

Schizophrenia is considered a debilitating neurodevelopmental psychiatric disorder and its pharmacotherapy remains problematic without recent major advances. The development of interventions able to prevent the emergence of schizophrenia would therefore represent an enormous progress. Here, we investigated whether treatment with cannabidiol (CBD - a compound of Cannabis sativa that presents an antipsychotic profile in animals and humans) during peri-adolescence would prevent schizophrenia-like behavioral abnormalities in an animal model of schizophrenia: the spontaneously hypertensive rat (SHR) strain. Wistar rats and SHRs were treated with vehicle or CBD from 30 to 60 post-natal days. In experiment 1, schizophrenia-like behaviors (locomotor activity, social interaction, prepulse inhibition of startle and contextual fear conditioning) were assessed on post-natal day 90. Side effects commonly associated with antipsychotic treatment were also evaluated: body weight gain and catalepsy throughout the treatment, and oral dyskinesia 48 h after treatment interruption and on post-natal day 90. In experiment 2, serum levels of triglycerides and glycemia were assessed on post-natal day 61. In experiment 3, levels of BDNF, monoamines, and their metabolites were evaluated on post-natal days 61 and 90 in the prefrontal cortex and striatum. Treatment with CBD prevented the emergence of SHRs' hyperlocomotor activity (a model for the positive symptoms of schizophrenia) and deficits in prepulse inhibition of startle and contextual fear conditioning (cognitive impairments). CBD did not induce any of the potential motor or metabolic side effects evaluated. Treatment with CBD increased the prefrontal cortex 5-HIAA/serotonin ratio and the levels of 5-HIAA on post-natal days 61 and 90, respectively. Our data provide pre-clinical evidence for a safe and beneficial effect of peripubertal and treatment with CBD on preventing positive and cognitive symptoms of schizophrenia, and suggest the involvement of the serotoninergic system on this effect.

Psychotic-like experiences in pre-adolescence: what precedes the antecedent symptoms of severe mental illness?

OBJECTIVE

Adolescent psychotic-like experiences predict the onset of psychosis, but also predict subsequent non-psychotic disorders. Therefore, it is crucial to better understand the aetiology of psychotic-like experiences. This study examined whether (a) child emotional and behavioural problems at 3 and 6 years, or (b) childhood adversities were associated with psychotic-like experiences at age 10 years.

METHOD

This prospective study was embedded in the Generation R Study; 3984 children (mean age 10 years) completed a psychotic-like experiences questionnaire. Mothers reported problems of their child at ages 3, 6 and 10 years. Additionally, mothers were interviewed about their child's adversities.

RESULTS

Psychotic-like experiences were endorsed by ~20% of children and predicted by both emotional and behavioural problems at 3 years (e.g. emotional-reactive problems: OR_adjusted = 1.10, 95% CI: 1.06-1.15, aggressive behaviour: OR_adjusted = 1.03, 95% CI: 1.02-1.05) and 6 years (e.g. anxious/depressed problems: OR_adjusted = 1.11, 95% CI: 1.06-1.15, aggressive behaviour: OR_adjusted = 1.04, 95% CI: 1.04-1.05). Childhood adversities were associated with psychotic-like experiences (>2 adversities: OR_adjusted = 2.24, 95% CI: 1.72-2.92), which remained significant after adjustment for comorbid psychiatric problems.

CONCLUSION

This study demonstrated associations between early adversities, childhood emotional and behavioural problems and pre-adolescent psychotic-like experiences, which will improve the understanding of children at increased risk of severe mental illness.

Attention Deficit Hyperactivity Disorder Symptoms and Psychosis in 22q11.2 Deletion Syndrome

OBJECTIVE

22q11.2 Deletion Syndrome (22q11.2DS) is associated with increased risk for schizophrenia in adulthood while Attention Deficit Hyperactivity Disorder (ADHD) is the most prevalent diagnosis in childhood. Inattention symptoms are pronounced in 22q11.2DS and given that attentional impairment is a core feature of schizophrenia, inattention symptoms may reflect underlying ADHD, psychosis, or both. We investigate whether inattention is associated with psychosis in 22q11.2DS and in other groups at risk for psychosis but without the deletion (ND) (idiopathic clinical risk and first degree family members of individuals with schizophrenia).

METHODS

One hundred thirty-seven individuals with 22q11.2DS (mean age: 14.0), 84 ND individuals with subthreshold psychosis (mean age: 16.9) and 31 ND individuals with family history of psychosis (mean age: 17.0) were included in the study. Psychopathology was assessed using research diagnostic assessments.

RESULTS

ADHD total symptoms were associated with overall levels of subthreshold psychosis symptoms in 22q11.2DS (β = .8, P = .04). Inattention symptoms were specifically associated with positive (β = .5, P = .004), negative (β = .5, P = .03), and disorganized (β = .5, P < .001) symptoms, while hyperactivity-impulsivity symptoms were associated with disorganized symptoms (β = .5, P = .01). The prevalence of ADHD inattention symptoms was higher in 22q11.2DS with subthreshold psychosis compared to ND individuals with subthreshold psychosis (P < .001), even when adjusting for cognitive impairment and overall psychopathology. The pattern was similar when comparing individuals with 22q11.2DS and ND individuals with family history of psychosis.

CONCLUSIONS

This is the first study to examine the associations between ADHD symptoms and psychosis in 22q11.2DS. Our findings support a potentially important role of ADHD inattention symptoms in psychosis in 22q11.2DS.

Bullying Mediates Between Attention-Deficit/Hyperactivity Disorder in Childhood and Psychotic Experiences in Early Adolescence

Although a childhood diagnosis of attention-deficit/hyperactivity disorder (ADHD) is known to be linked to psychotic experiences and psychotic disorders in later life, the developmental trajectories that could explain this association are unknown. Using a sample from the prospective population-based Avon Longitudinal Study of Parents and Children (ALSPAC) (N = 8247), we hypothesized that the previously reported association of ADHD combined subtype in childhood and psychotic experiences in early adolescence is mediated by traumatic events and by involvement in bullying. Moreover, we expected this mediation to be specific to ADHD and tested this by comparison with specific phobia. Children with ADHD combined subtype at age 7 were more often involved in bullying at age 10 (OR 3.635, 95% CI 1.973-6.697) and had more psychotic experiences at age 12 (OR 3.362, 95% CI 1.781-6.348). Moreover, children who were involved in bullying had more psychotic experiences (2.005, 95% CI 1.684-2.388). Bullying was a significant mediator between ADHD and psychotic experiences accounting for 41%-50% of the effect. Traumatic events from birth to age 11 were also significantly associated with ADHD combined subtype and psychotic experiences; however, there was no evidence of mediation. Specific phobia was significantly associated with psychotic experiences, but not with bullying. To conclude, bullying is a relevant translating mechanism from ADHD in childhood to psychotic experiences in early adolescence. Interventions that eliminate bullying in children with ADHD could potentially reduce the risk of having psychotic experiences in later life by up to 50%. Clinicians should thus screen for bullying in routine assessments of children with ADHD.