Attention-deficit/hyperactivity disorder (ADHD) is a multifactorial and clinically heterogeneous disorder that is associated with tremendous financial burden, stress to families, and adverse academic ...and vocational outcomes. Attention-deficit/hyperactivity disorder is highly prevalent in children worldwide, and the prevalence of this disorder in adults is increasingly recognized. Studies of adults with a diagnosis of childhood-onset ADHD indicate that clinical correlates—demographic, psychosocial, psychiatric, and cognitive features—mirror findings among children with ADHD. Predictors of persistence of ADHD include family history of the disorder, psychiatric comorbidity, and psychosocial adversity. Family studies of ADHD have consistently supported its strong familial nature. Psychiatric disorders comorbid with childhood ADHD include oppositional defiant and conduct disorders, whereas mood and anxiety disorders are comorbid with ADHD in both children and adults. Pregnancy and delivery complications, maternal smoking during pregnancy, and adverse family environment variables are considered important risk factors for ADHD. The etiology of ADHD has not been clearly identified, although evidence supports neurobiologic and genetic origins. Structural and functional imaging studies suggest that dysfunction in the fronto-subcortical pathways, as well as imbalances in the dopaminergic and noradrenergic systems, contribute to the pathophysiology of ADHD. Medication with dopaminergic and noradrenergic activity seems to reduce ADHD symptoms by blocking dopamine and norepinephrine reuptake. Such alterations in dopaminergic and noradrenergic function are apparently necessary for the clinical efficacy of pharmacologic treatments of ADHD.
Objective: Mind wandering, the unintended shifting of attention from a task, has been previously associated with symptoms of ADHD. To this end, we conducted a literature search to investigate the ...association between mind wandering and ADHD. Method: We conducted a systematic search of the literature of relevant articles assessing mind wandering and ADHD in PubMed, PsycINFO/OVID, and Medline. Included were original articles in English that had operationalized definitions of ADHD and mind wandering, adequate sample size, and reliance on statistical evaluation of findings. Excluded were reviews, opinions, and case reports. Results: Only nine studies met our a priori inclusion and exclusion criteria (N = 8 in adults; N = 1 in pediatrics). Findings suggest that ADHD is frequently associated with spontaneous mind wandering and when present heralds more functional impairments. Conclusion: The limited research on mind wandering in ADHD indicates that it is prevalent and morbid supporting further research on the subject.
This study examined the persistence of attention deficit hyperactivity disorder (ADHD) into adulthood.
We analyzed data from published follow-up studies of ADHD. To be included in the analysis, these ...additional studies had to meet the following criteria: the study included a control group and it was clear from the methods if the diagnosis of ADHD included subjects who did not meet full criteria but showed residual and impairing signs of the disorder. We used a meta-analysis regression model to separately assess the syndromatic and symptomatic persistence of ADHD.
When we define only those meeting full criteria for ADHD as having 'persistent ADHD', the rate of persistence is low, approximately 15% at age 25 years. But when we include cases consistent with DSM-IV's definition of ADHD in partial remission, the rate of persistence is much higher, approximately 65%.
Our results show that estimates of ADHD's persistence rely heavily on how one defines persistence. Yet, regardless of definition, our analyses show that evidence for ADHD lessens with age. More work is needed to determine if this reflects true remission of ADHD symptoms or is due to the developmental insensitivity of diagnostic criteria for the disorder.
Abstract Introduction Major Depressive Disorder (MDD) among youth is a public health concern. Our aim was to examine the current body of knowledge to better characterize the prevalence and morbidity ...associated with subthreshold forms of MDD among youth. Given that MDD tends to develop gradually over time, we hypothesized a high prevalence and considerable impairment associated with youth suffering from depressive symptoms that fall short of full, syndromic status. Methods A literature search was conducted using PubMed exclusively to identify studies assessing the prevalence and clinical characteristics of subthreshold MDD in adolescents. Results Six scientific papers that met our priori inclusion and exclusion criteria were identified. All papers sampled adolescents. The prevalence of subthreshold MDD ranged from 5% over the past year, to 29% over the two weeks prior to screening. These papers reported clinically significant morbidity associated with subthreshold MDD among adolescents, with evidence for elevated rates of psychiatric comorbidities, impaired functioning in social and familial domains, increased suicidality, and frequent mental health service utilization. Limitations Though we examined a sizeable and diverse sample, we only identified six cross-sectional informative studies for this review. Variability of subthreshold MDD and major outcome definitions across studies, likely limits the specificity of findings. Conclusions Subthreshold MDD is prevalent among youth, and is associated with emotional and social impairments that reach the level of obtaining clinical care. These findings could lead to early intervention efforts aimed at mitigating the adverse outcomes associated with subthreshold MDD as well as the progression to full syndrome MDD. Our review documents that regardless of whether progression to full diagnostic status occurs, this condition is morbid.
Objective: High rates of substance-use disorders (SUD) have been found in samples of adolescents and adults with attention-deficit/hyperactivity disorder (ADHD). Predictors of SUD in children with ...ADHD who are at risk for the development of SUDs remain understudied. The main aims of this study were to identify clinically meaningful characteristics of children that predicted the future development of SUDs and to see whether the role of these characteristics varied by sex. Method: Subjects were children and adolescents with (n = 268; mean age plus or minus standard deviation = 10.9 plus or minus 3.2 years) and without (n = 229; mean age 11.9 plus or minus 3.3 years) "DSM-III-R" ADHD followed prospectively and blindly over a 10-year follow-up period onto young adult years. Subjects were assessed with structured diagnostic interviews for psychopathology and SUDs. Results: Over the 10-year follow-up period, ADHD was found to be a significant predictor of any SUD (hazards ratio 1.47; 95% confidence interval 1.07-2.02; p = 0.01) and cigarette smoking (2.38; 1.61-3.53; p less than 0.01). Within ADHD, comorbid conduct disorder (2.74; 1.66-4.52; p less than 0.01) and oppositional defiant disorder (2.21; 1.40-3.51; p less than 0.01) at baseline were also found to be significant predictors of SUDs. Similar results were found for cigarette-, alcohol-, and drug-use disorders. There were few meaningful sex interaction effects. No clinically significant associations were found for any social or family environment factors or for cognitive functioning factors (p greater than 0.05 for all comparisons). Conclusions: These results indicate that ADHD is a significant risk factor for the development of SUDs and cigarette smoking in both sexes. (Contains 2 figures and 2 tables.)
Objective:
The worldwide prevalence estimates of attention deficit hyperactivity disorder (ADHD) hyperkinetic disorder (HD) are highly heterogeneous. Presently, the reasons for this discrepancy ...remain poorly understood. The purpose of this study was to determine the possible causes of the varied worldwide estimates of the disorder and to compute its worldwide-pooled prevalence.
Method:
The authors searched MEDLINE and PsycINFO databases from January 1978 to December 2005 and reviewed textbooks and reference lists of the studies selected. Authors of relevant articles from North America, South America, Europe, Africa, Asia, Oceania, and the Middle East and ADHD HD experts were contacted. Surveys were included if they reported point prevalence of ADHD HD for subjects 18 years of age or younger from the general population or schools according to DSM or ICD criteria.
Results:
The literature search generated 9,105 records, and 303 full-text articles were reviewed. One hundred and two studies comprising 171,756 subjects from all world regions were included. The ADHD HD worldwide-pooled prevalence was 5.29%. This estimate was associated with significant variability. In the multivariate metaregression model, diagnostic criteria, source of information, requirement of impairment for diagnosis, and geographic origin of the studies were significantly associated with ADHD HD prevalence rates. Geographic location was associated with significant variability only between estimates from North America and both Africa and the Middle East. No significant differences were found between Europe and North America.
Conclusions:
Our findings suggest that geographic location plays a limited role in the reasons for the large variability of ADHD HD prevalence estimates worldwide. Instead, this variability seems to be explained primarily by the methodological characteristics of studies.
Use of tobacco products is injurious to health in men and women. However, tobacco use by pregnant women receives greater scrutiny because it can also compromise the health of future generations. More ...men smoke cigarettes than women. Yet the impact of nicotine use by men upon their descendants has not been as widely scrutinized. We exposed male C57BL/6 mice to nicotine (200 μg/mL in drinking water) for 12 wk and bred the mice with drug-naïve females to produce the F1 generation. Male and female F1 mice were bred with drug-naïve partners to produce the F2 generation. We analyzed spontaneous locomotor activity, working memory, attention, and reversal learning in male and female F1 and F2 mice. Both male and female F1 mice derived from the nicotine-exposed males showed significant increases in spontaneous locomotor activity and significant deficits in reversal learning. The male F1 mice also showed significant deficits in attention, brain monoamine content, and dopamine receptor mRNA expression. Examination of the F2 generation showed that male F2 mice derived from paternally nicotine-exposed female F1 mice had significant deficits in reversal learning. Analysis of epigenetic changes in the spermatozoa of the nicotine-exposed male founders (F0) showed significant changes in global DNA methylation and DNA methylation at promoter regions of the dopamine D2 receptor gene. Our findings show that nicotine exposure of male mice produces behavioral changes in multiple generations of descendants. Nicotine-induced changes in spermatozoal DNA methylation are a plausible mechanism for the transgenerational transmission of the phenotypes. These findings underscore the need to enlarge the current focus of research and public policy targeting nicotine exposure of pregnant mothers by a more equitable focus on nicotine exposure of the mother and the father.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
ObjectiveThe existence of comorbidity between attention deficit hyperactivity disorder (ADHD) and bipolar I disorder has been documented in clinical and epidemiological studies, in studies of ...children and adults, and in diagnosed ADHD and bipolar I patient samples. Yet questions remain about the validity of diagnosing bipolar I disorder in ADHD youth. The authors aim to clarify these issues by reviewing family genetic studies of ADHD and bipolar I disorder.MethodThe authors applied random-effects meta-analysis to family genetic studies of ADHD and bipolar I disorder. Twenty bipolar proband studies provided 37 estimates of the prevalence of ADHD in 4,301 relatives of bipolar probands and 1,937 relatives of comparison probands. Seven ADHD proband studies provided 12 estimates of the prevalence of bipolar I disorder in 1,877 relatives of ADHD probands and 1,601 relatives of comparison probands.ResultsThese studies found a significantly higher prevalence of ADHD among relatives of bipolar probands and a significantly higher prevalence of bipolar I disorder among relatives of ADHD probands. These results could not be accounted for by publication biases, unusual results from any one observation, sample characteristics, or study design features. The authors found no evidence of heterogeneity in the ADHD or bipolar family studies.ConclusionsThe results suggest that ADHD plus bipolar comorbidity cannot be accounted for by misdiagnoses, but additional research is needed to rule out artifactual sources of comorbidity. More research is also needed to determine whether comorbidity of ADHD and bipolar I disorder constitutes a familial subtype distinct from its constituent disorders, which if confirmed would have implications for diagnostic nosology and genetic studies.
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