Gender differences in adults with attention-deficit/hyperactivity disorder: A narrative review

Determinants of Pharmacological Treatment Initiation and Persistence in Publicly Insured Adults With Attention-Deficit/Hyperactivity Disorder

OBJECTIVES

The objectives of this study were to describe the longitudinal trends of pharmacological treatment initiation and persistence in adult patients with attention-deficit/hyperactivity disorder (ADHD) and to explore how patients' sociodemographic and clinical characteristics affect these patterns.

METHODS

A retrospective cohort of 23,747 adult patients with new ADHD episodes was assembled using Medicaid extract files of 29 US states from 1999 and 2010. Sociodemographic and clinical characteristics of treatment initiators and noninitiators, and treatment persistent and nonpersistent patients were compared using multivariable logistic regression.

RESULTS

The overall treatment initiation and 1-year persistence rate was 22.5% and 34.2%, respectively. After adjustment, the propensity of initiating pharmacotherapy and being persistent tripled (2010 vs 2000; odds ratio, 3.25; 95% confidence interval, 2.61-4.04) and almost doubled (2009 vs 2000; odds ratio, 1.86; 95% confidence interval, 1.20-2.90) over the study period. Male, racial and ethnic minorities, and younger age groups had a decreased propensity for treatment initiation and persistence. The likelihood of initiating treatment was similar for rural and urban residents but varied among different US states. Severe mental comorbidities and, concordantly, use of antipsychotics or mood stabilizers reduced the propensity of treatment initiation but had little effect on persistence. Patients filling sustained release stimulants were most likely to be persistent. Finally, preexisting cardiovascular conditions reduced the likelihood of receiving treatment but were not associated with persistence.

CONCLUSIONS

The propensity to initiate and persist on pharmacological treatment in adults with ADHD has increased in the last decade but remains low. Treatment patterns were closely related to several sociodemographic and clinical determinants. Our findings provide valuable information to ensure appropriate treatment choices for these patients.

Reading Comprehension in Boys with ADHD: The Mediating Roles of Working Memory and Orthographic Conversion

Reading comprehension difficulties in children with ADHD are well established; however, limited information exists concerning the cognitive mechanisms that contribute to these difficulties and the extent to which they interact with one another. The current study examines two broad cognitive processes known to be involved in children's reading comprehension abilities-(a) working memory (i.e., central executive processes [CE], phonological short-term memory [PH STM], and visuospatial short-term memory [VS STM]) and (b) orthographic conversion (i.e., conversion of visually presented text to a phonological code)-to elucidate their unique and interactive contribution to ADHD-related reading comprehension differences. Thirty-one boys with ADHD-combined type and 30 typically developing (TD) boys aged 8 to 12 years (M = 9.64, SD = 1.22) were administered multiple counterbalanced tasks assessing WM and orthographic conversion processes. Relative to TD boys, boys with ADHD exhibited significant deficits in PH STM (d = -0.70), VS STM (d = -0.92), CE (d = -1.58), and orthographic conversion (d = -0.93). Bias-corrected, bootstrapped mediation analyses revealed that CE and orthographic conversion processes modeled separately mediated ADHD-related reading comprehension differences partially, whereas PH STM and VS STM did not. CE and orthographic conversion modeled jointly mediated ADHD-related reading comprehension differences fully wherein orthographic conversion's large magnitude influence on reading comprehension occurred indirectly through CE's impact on the orthographic system. The findings suggest that adaptive cognitive interventions designed to improve reading-related outcomes in children with ADHD may benefit by including modules that train CE and orthographic conversion processes independently and interactively.

Adult ADHD: Risk Factor for Dementia or Phenotypic Mimic?

Attention-deficit hyperactivity disorder (ADHD) has historically been considered a disorder of childhood and adolescence. However, it is now recognized that ADHD symptoms persist into adulthood in up to 60% of individuals. Some of the cognitive symptoms that characterize ADHD (inability to provide sustained attention or mental effort, difficulty organizing or multi-tasking, forgetfulness) may closely resemble symptoms of prodromal dementia, also often referred to as mild cognitive impairment (MCI), particularly in patients over age 50. In addition to the overlap in cognitive symptoms, adults with ADHD and those with MCI may also share a number of behavioral and psychiatric symptoms, including sleep disturbances, depression, and anxiety. As a result, both syndromes may be difficult to distinguish clinically in older patients, particularly those who present to memory clinics with subjective cognitive complaints and fear the onset of a neurodegenerative process: is it ADHD, MCI, or both? Currently, it is unclear whether ADHD is associated with incipient dementia or is being misdiagnosed as MCI due to symptom overlap, as there exist data supporting either possibility. Here, we aim to elucidate this issue by outlining three hypothetical ways in which ADHD and MCI might relate to each other, providing an overview of the evidence relevant to each hypothesis, and delineating areas for future research. This is a question of considerable importance, with implications for improved diagnostic specificity of early dementia, improved accuracy of disease prevalence estimates, and better identification of individuals for targeted treatment.

The Effect of Attention-Deficit/Hyperactivity Disorder and Methylphenidate Treatment on the Adult Auditory Temporal Order Judgment Threshold

PURPOSE

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition notes that attention-deficit/hyperactivity disorder (ADHD) diagnosed in childhood will persist into adulthood among at least some individuals. There is a paucity of evidence, however, regarding whether other difficulties that often accompany childhood ADHD will also continue into adulthood, specifically auditory processing deficits. The aim of this study was to examine the effect of ADHD and the stimulant medication methylphenidate on auditory perception performance among adults.

METHOD

A total of 33 adults diagnosed with ADHD according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria (ADHD group) and 48 adults without ADHD (non-ADHD group) performed an auditory temporal order judgment task. Participants with ADHD performed the task twice: with and without taking methylphenidate (Ritalin), in random order.

RESULTS

Temporal order judgment thresholds of the ADHD group were significantly higher than those of the non-ADHD group. Methylphenidate significantly decreased temporal order judgment thresholds within the ADHD group, making their performance similar to the non-ADHD participants.

CONCLUSIONS

Auditory processing difficulties of those diagnosed with ADHD seem to persist into adulthood. Similar to findings with children, methylphenidate treatment improves performance on tasks requiring this ability among adults. Therefore, given the association between auditory temporal processing and linguistic skills, the beneficial effect of methylphenidate on adults' academic achievement may be accomplished by positively affecting auditory temporal processing. Further studies in this line of research are needed.

Parental ADHD symptoms and parenting behaviors: A meta-analytic review

Attention-deficit/hyperactivity disorder (ADHD) persists throughout the lifespan, and there are known impairments associated with adult ADHD. Understanding ADHD-related impairments in the parenting domain is particularly important given that the children of adults with ADHD also are likely to have ADHD, and there is potential for parenting to alter the developmental outcomes of these children. The present study quantitatively synthesizes evidence regarding the associations between parental ADHD symptoms and parenting behaviors. Across 32 studies, this meta-analysis found that parental ADHD symptoms accounted for 2.9%, 3.2%, and 0.5% of the variance of harsh, lax, and positive parenting, respectively. Greater parental ADHD symptoms were associated with less positive and more harsh and lax parenting behaviors. Variables, such as the proportion of children in the sample diagnosed with ADHD, child gender, and method/rater variance, moderated the strength of these relations. Results also suggest more similarities than differences in the associations between parenting behaviors and the two dimensions of inattention and hyperactivity/impulsivity symptoms. Overall, parental ADHD symptoms are significantly associated with parenting behaviors with effect sizes similar to the associations found between other parental psychopathologies and parenting, although the associations remain relatively small. The paper concludes with comments regarding remaining gaps in the literature that warrant further research and the clinical implications of the associations between parental ADHD symptoms and parenting.

Experiences of employed women with attention deficit hyperactive disorder: A phenomenological study

BACKGROUND

Employees with attention-deficit/hyperactivity disorder (ADHD) face various risks in the workplace. Little is known of the specific challenges women with ADHD experience.

OBJECTIVE

To explore the experiences of working women with ADHD and learn the strategies and accommodations that facilitate their maintaining employment.

METHOD

Qualitative phenomenological approach was used to echo women's subjective perceptions and experiences representing their daily interactions in their workplace. In-depth interviews were conducted with eleven tertiary-educated employed women (M = 33.5; SD = 6.61 years), diagnosed with ADHD and the transcripts were analyzed by three researchers, using the qualitative phenomenological approach.

RESULTS

Most interviewed women with ADHD described interactions with their workplace as confusing, overwhelming, and chaotic. They perceived their ADHD as a significant obstacle to success in employment that also conferred some advantages. Three interview themes are explored here (1) challenges in coping with job demands and the workplace, including the disclosure dilemma; (2) personal coping strategies; (3) useful accommodations.

CONCLUSIONS

For the women interviewed, employment was important for their self-identity, beyond simply making a living. Their experiences indicate impaired executive functioning and inhibition and sensory sensitivity, consistently with theoretical models for ADHD. They identified gender-specific issues, such as using medication during pregnancy, which led them to seek for non-pharmacological coping mechanisms. They contributed practical knowledge regarding employee-led adaptations and employer-provided workplace accommodations.

The Effects of Perinatal Oxycodone Exposure on Behavioral Outcome in a Rodent Model

Opiate addiction is now a major public health problem. Perinatal insults and exposure to opiates such as morphine in utero are well known to affect development of the hypothalamic-pituitary-adrenal axis of the offspring adversely and are associated with a higher risk of developing neurobehavioral problems. Oxycodone is now one of the most frequently abused pain killers during pregnancy; however, limited data are available regarding whether and how perinatal oxycodone exposure (POE) alters neurobehavioral outcomes of the offspring. We demonstrated that exposure to 0.5 mg/kg/day oxycodone in utero was associated with hyperactivity in adult rats in an open field. No significant effects of POE were detected on isolation-induced ultrasonic vocalizations in the early postnatal period or on learning and memory in the water maze in adult offspring. Our findings are consistent with hyperactivity problems identified in children exposed to opiates in utero.

The risk of eating disorders comorbid with attention-deficit/hyperactivity disorder: A systematic review and meta-analysis

OBJECTIVE

There has been interest in whether people with Attention-Deficit/Hyperactivity Disorder (ADHD) are at higher risk of developing an Eating Disorder (ED). The aim of this study was estimate the size of this association with a meta-analysis of studies.

METHODS

We retrieved studies following PRISMA guidelines from a broad range of databases.

RESULTS

Twelve studies fitted our primary aim in investigating ED in ADHD populations (ADHD = 4,013/Controls = 29,404), and five exploring ADHD in ED populations (ED = 1,044/Controls = 11,292). The pooled odds ratio of diagnosing any ED in ADHD was increased significantly, 3.82 (95% CI:2.34-6.24). A similar level of risk was found across all ED syndromes [Anorexia Nervosa = 4.28 (95% CI:2.24-8.16); Bulimia Nervosa = 5.71 (95% CI: 3.56-9.16) and Binge Eating Disorder = 4.13 (95% CI:3-5.67)]. The risk was significantly higher if ADHD was diagnosed using a clinical interview [5.89 (95% CI:4.32-8.04)] rather than a self-report instrument [2.23 (95% CI:1.23-4.03)]. The pooled odds ratio of diagnosing ADHD in participants with ED was significantly increased, 2.57 (95% CI:1.30-5.11). Subgroup analysis of cohorts with binge eating only yielded a risk of 5.77 (95% CI:2.35-14.18). None of the variables examined in meta-regression procedures explained the variance in effect size between studies.

DISCUSSION

People with ADHD have a higher risk of comorbidity with an ED and people with an ED also have higher levels of comorbidity with ADHD. Future studies should address if patients with this comorbidity have a different prognosis, course and treatment response when compared to patients with either disorder alone.

RESUMEN OBJETIVO

Ha habido interés en saber si la gente con Trastorno por Déficit de Atención e Hiperactividad (TDAH) están en mayor riesgo de desarrollar un Trastorno de la Conducta Alimentaria (TCA). El objetivo de este estudio fue estimar el tamaño de esta asociación con un meta-análisis de los estudios. Métodos: Recuperamos estudios de una amplia gama base de datos,  que siguen los lineamientos PRISMA. Resultados: Doce estudios encajaron con nuestro objetivo primario de investigar los TCA en poblaciones con TDAH (TDAH = 4,013/Controles = 29,404), y 5 exploraron TDAH en poblaciones con TCA (TCA = 1,044/Controles = 11,292). El odds ratio (OR) agrupado de diagnosticar cualquier TCA en el TDAH se incrementó significativamente, 3.82 (95% CI:2.34-6.24). Un nivel de riesgo similar fue encontrado en todos los síndromes de TCA [Anorexia Nervosa = 4.28 (95% CI:2.24-8.16); Bulimia Nervosa = 5.71 (95% CI:3.56-9.16) y Trastorno por Atracón = 4.13 (95% CI: 3-5.67)]. El riesgo fue significativamente mayor si el TDAH fue diagnosticado utilizando una entrevista clínica [5.89 (95% CI:4.32-8.04)] en lugar de un instrumento de auto-reporte [2.23 (95% CI:1.23-4.03)]. El odds ratio (OR) agrupado de diagnosticar TDAH en participantes con TCA fue significativamente incrementado, 2.57 (95% CI:1.30-5.11). El análisis de los subgrupos de cohort con atracones solamente produjo un riesgo de 5.77 (95% CI:2.35-14.18). Ninguna de las variables examinadas en los procedimientos de meta-regresión explicaron la varianza en el tamaño del efecto entre los estudios. Discusión: La gente con TDAH tiene un mayor riesgo de comorbilidad con un TCA y la gente con un TCA también tiene niveles altos de comorbilidad con TDAH. Los estudios futuros deberán abordar si los pacientes con esta comorbilidad tienen diferente pronóstico, curso y respuesta a tratamiento cuando son comparados con pacientes que solamente tienen uno de los trastornos.  © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016) © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016; 49:1045-1057).

The use of compensatory strategies in adults with ADHD symptoms

This study examined the use of compensatory strategies reported by adults with ADHD symptoms and their relation to measures of functioning. Forty-nine adults (55.1 % female) completed a structured diagnostic interview to assess ADHD, and responses were coded for compensatory strategies: Adaptation, Paying Attention, Organization, External Support, and Avoidance. The majority of adults with ADHD symptoms reported using compensatory strategies, and their reported strategy use in childhood was related to their use in adulthood. No gender differences were found in the use of strategies, although Organization and External Support were used more often for inattention than for hyperactive/impulsive symptoms. Use of the compensatory strategy, Adaptation, was significantly related to measures of functioning, and the use of strategies reduced the negative relationship between ADHD symptoms and parenting difficulties. Results encourage the development of compensatory strategies among adults with ADHD symptoms, as well as provide recommendations for treatment programs.

Burden of illness and health care resource utilization in adult psychiatric outpatients with attention-deficit/hyperactivity disorder in Europe

OBJECTIVE

To assess the burden of illness and health care resource utilization of adult nonpsychotic psychiatric outpatients with attention-deficit/hyperactivity disorder (ADHD) in Europe.

METHODS

This was a multicountry, cross-sectional, observational study where unselected routine patients from clinical psychiatric outpatient settings were screened and assessed for ADHD. Patients were evaluated using the Clinical Global Impressions of Severity (CGI-S) scale, the Sheehan Disability Scale (SDS), and the EuroQol-5 Dimensions questionnaire. Data on comorbidities, functional impairment, and health care resource utilization were captured.

RESULTS

The study enrolled 2284 patients, of whom 1986 completed the study. The prevalence of ADHD was 17.4%, of whom 46.0% had a previous ADHD diagnosis. Patients with ADHD had a high clinical burden with psychiatric comorbidities, especially depression (43.0%) and anxiety disorders (36.4%). Substance abuse (9.2% vs. 3.4%) and alcohol abuse (10.3% vs. 5.2%) were more common in the ADHD cohort vs. the non-ADHD cohort. Only 11.5% of the patients with ADHD had no other psychiatric disorder. Various measures indicated a significantly poorer level of functioning for patients with ADHD than without ADHD, as indicated by higher scores for CGI-S (3.8 vs. 3.3) and SDS (18.9 vs. 11.6) and higher percentages of debt (35.5% vs. 24.3%) and criminality (13.8% vs. 6.1%). Lastly, the health care resource utilization was considerable and similar between adult psychiatric outpatients diagnosed and not diagnosed with ADHD.

CONCLUSIONS

Although care was taken when choosing the sites for this study, to make it representative of the general outpatient adult psychiatric population, caution should be advised in generalizing the findings of our study to the general ADHD or psychiatric outpatient population. This was an observational study, thus no inference on causality can be drawn. Having ADHD imposes a considerable health and social burden on patient and health care resource utilization comparable to other chronic psychiatric disorders.

Premature responding is associated with approach to a food cue in male and female heterogeneous stock rats

RATIONALE

Disorders of behavioral regulation, including attention deficit hyperactivity disorder (ADHD) and drug addiction, are in part due to poor inhibitory control, attentional deficits, and hyper-responsivity to reward-associated cues.

OBJECTIVES

To determine whether these traits are related, we tested genetically variable male and female heterogeneous stock rats in the choice reaction time (CRT) task and Pavlovian conditioned approach (PavCA). Sex differences in the response to methylphenidate during the CRT were also assessed.

METHODS

In the CRT task, rats were required to withhold responding until one of two lights indicated whether responses into a left or right port would be reinforced with water. Reaction time on correct trials and premature responses were the operational definitions of attention and response inhibition, respectively. Rats were also pretreated with oral methylphenidate (0, 2, 4 mg/kg) during the CRT task to determine whether this drug would improve performance. Subsequently, during PavCA, presentation of an illuminated lever predicted the delivery of a food pellet into a food-cup. Lever-directed approach (sign-tracking) and food-cup approach (goal-tracking) were the primary measures, and rats were categorized as "sign-trackers" and "goal-trackers" using an index based on these measures.

RESULTS

Sign-trackers made more premature responses than goal-trackers but showed no differences in reaction time. There were sex differences in both tasks, with females having higher sign-tracking, completing more CRT trials, and making more premature responses after methylphenidate administration.

CONCLUSIONS

These results indicate that response inhibition is related to reward-cue responsivity, suggesting that these traits are influenced by common genetic factors.

Is There a Female Protective Effect Against Attention-Deficit/Hyperactivity Disorder? Evidence From Two Representative Twin Samples

OBJECTIVE

Attention-deficit/hyperactivity disorder (ADHD) is more frequent in males than in females. The "female protective effect" posits that females undergo greater exposure to etiological factors than males in order to develop ADHD, leading to the prediction that relatives of females with ADHD will display more ADHD behaviors. We thus tested whether cotwins of females displaying extreme ADHD traits would display more ADHD traits than cotwins of males displaying extreme ADHD traits.

METHOD

Parents of approximately 7,000 pairs of nonidentical twins in Sweden, and approximately 4,000 pairs of twins in England and Wales, completed dimensional assessments of ADHD traits. Probands were selected on the basis of scoring within the highest 10% of the distribution in each sample. Dimensional scores of cotwins of probands, as well as the categorical recurrence rate, were investigated by proband sex.

RESULTS

Cotwins of female probands displayed higher mean ADHD trait scores (mean = 0.62-0.79) than cotwins of male probands (mean = 0.38-0.55) in both samples. This trend was significant in the Swedish sample (p < .01) and when the 2 samples were merged into a single, larger sample (p < .001). When the samples were merged, there was also a significant association between proband sex and cotwin's categorical status, with more cotwins of female probands also being probands than cotwins of male probands.

CONCLUSION

These findings support a female protective effect against ADHD behaviors, suggesting that females require greater exposure to genetic and environmental factors associated with ADHD in order to develop the condition.

Is hyperactivity ubiquitous in ADHD or dependent on environmental demands? Evidence from meta-analysis

Hyperactivity, or excess gross motor activity, is considered a core and ubiquitous characteristic of ADHD. Alternate models question this premise, and propose that hyperactive behavior reflects, to a large extent, purposeful behavior to cope with environmental demands that interact with underlying neurobiological vulnerabilities. The present review critically evaluates the ubiquity and environmental modifiability of hyperactivity in ADHD through meta-analysis of 63 studies of mechanically measured activity level in children, adolescents, and adults with ADHD relative to typically developing groups. Random effects models corrected for publication bias confirmed elevated gross motor activity in ADHD (d=0.86); surprisingly, neither participant age (child vs. adult) nor the proportion of each ADHD sample diagnosed with the inattentive subtype/presentation moderated this effect. In contrast, activity level assessed during high cognitive load conditions in general (d=1.14) and high executive functioning demands in particular (d=1.39) revealed significantly higher effect sizes than activity level during low cognitive load (d=0.36) and in-class schoolwork (d=0.50) settings. Low stimulation environments, more rigorous diagnostic practices, actigraph measurement of movement frequency and intensity, and ADHD samples that included fewer females were also associated with larger effects. Overall, the results are inconsistent with DSM-5 and ADHD models that a) describe hyperactivity as ubiquitous behavior, b) predict a developmental decline in hyperactivity, or c) differentiate subtypes/presentations according to perceived differences in hyperactive behavior. Instead, results suggest that the presence and magnitude of hyperactive behavior in ADHD may be influenced to a considerable extent by environmental factors in general, and cognitive/executive functioning demands in particular.