Sex-specific trajectories of ADHD symptoms from adolescence to young adulthood

Reports of current ADHD symptoms in adults with a childhood diagnosis of ADHD are often discrepant: While one subgroup reports a particularly high level of current ADHD symptoms, another reports-in contrast-a very low level. The reasons for this difference remain unclear. Although sex might play a moderating role, it has not yet been examined in this regard. In an epidemiological cohort study from birth to young adulthood, childhood ADHD diagnoses were assessed at the ages of 4.5, 8, and 11 years based on parent ratings. Sex-specific development of ADHD symptoms was analyzed from the age of 15 to 25 years via self-reported ADHD symptoms in participants with (n = 47) and without childhood ADHD (n = 289) using a random coefficient regression model. The congruence between parent reports and adolescents' self-ratings was examined, and the role of childhood ADHD diagnosis, childhood OCC/CD, and childhood internalizing disorder as possible sex-specific predictors of self-reported ADHD symptoms at age 25 years was investigated. With regard to self-reported ADHD symptoms, females with a childhood ADHD diagnosis reported significantly more ADHD symptoms compared to females without childhood ADHD and males with and without ADHD throughout adolescence and young adulthood. In contrast, males with childhood ADHD did not differ from control males either at age 15 or at age 25 years. Only in females did a childhood diagnosis of an externalizing disorder (ADHD and CD/ODD) predict self-reported ADHD symptoms by age 25 years. Our findings suggest that self-reports of young adults with a childhood diagnosis of ADHD are influenced by sex. Specifically, females with childhood ADHD report increased levels of ADHD symptoms upon reaching adulthood. To correctly evaluate symptoms and impairment in this subgroup, other, more objective, sources of information may be advisable, such as neurophysiological measures

Association of norepinephrine transporter (NET, SLC6A2) genotype with ADHD-related phenotypes: findings of a longitudinal study from birth to adolescence

Variation in the gene encoding for the norepinephrine transporter (NET, SLC6A2) has repeatedly been linked with ADHD, although there is some inconsistency regarding the association with specific genes. The variants for which most consistent association has been found are the NET variants rs3785157 and rs28386840. Here, we tested for their association with ADHD diagnosis and ADHD-related phenotypes during development in a longitudinal German community sample. Children were followed from age 4 to age 15, using diagnostic interviews to assess ADHD. Between the ages of 8 and 15 years, the Child Behavior Checklist (CBCL) was administered to the primary caregivers. The continuous performance task (CPT) was performed at age 15. Controlling for possible confounders, we found that homozygous carriers of the major A allele of the functional promoter variant rs28386840 displayed a higher rate of ADHD lifetime diagnosis. Moreover, homozygous carriers of the minor T allele of rs3785157 were more likely to develop ADHD and showed higher scores on the CBCL externalizing behavior scales. Additionally, we found that individuals heterozygous for rs3785157 made fewer omission errors in the CPT than homozygotes. This is the first longitudinal study to report associations between specific NET variants and ADHD-related phenotypes during the course of development

Effect of prenatal exposure to tobacco smoke on inhibitory control: neuroimaging results from a 25-year prospective study

IMPORTANCE: There is accumulating evidence relating maternal smoking during pregnancy to attention-deficit/hyperactivity disorder (ADHD) without elucidating specific mechanisms. Research investigating the neurobiological underpinnings of this disorder has implicated deficits during response inhibition. Attempts to uncover the effect of prenatal exposure to nicotine on inhibitory control may thus be of high clinical importance. OBJECTIVE: To clarify the influence of maternal smoking during pregnancy (hereafter referred to as prenatal smoking) on the neural circuitry of response inhibition and its association with related behavioral phenotypes such as ADHD and novelty seeking in the mother's offspring. DESIGN, SETTING, AND PARTICIPANTS: Functional magnetic resonance imaging was performed for the offspring at 25 years of age during a modified Eriksen flanker/NoGo task, and voxel-based morphometry was performed to study brain volume differences of the offspring. Prenatal smoking (1-5 cigarettes per day [14 mothers] or >5 cigarettes per day [24 mothers]) and lifetime ADHD symptoms were determined using standardized parent interviews at the offspring's age of 3 months and over a period of 13 years (from 2 to 15 years of age), respectively. Novelty seeking was assessed at 19 years of age. Analyses were adjusted for sex, parental postnatal smoking, psychosocial and obstetric adversity, maternal prenatal stress, and lifetime substance abuse. A total of 178 young adults (73 males) without current psychopathology from a community sample followed since birth (Mannheim, Germany) participated in the study. MAIN OUTCOMES AND MEASURES: Functional magnetic resonance imaging response, morphometric data, lifetime ADHD symptoms, and novelty seeking. RESULTS: Participants prenatally exposed to nicotine exhibited a weaker response in the anterior cingulate cortex (t168 = 4.46; peak Montreal Neurological Institute [MNI] coordinates x = -2, y = 20, z = 30; familywise error [FWE]-corrected P = .003), the right inferior frontal gyrus (t168 = 3.65; peak MNI coordinates x = 44, y = 38, z = 12; FWE-corrected P = .04), the left inferior frontal gyrus (t168 = 4.09; peak MNI coordinates x = -38, y = 36, z = 8; FWE-corrected P = .009), and the supramarginal gyrus (t168 = 5.03; peak MNI coordinates x = 64, y = -28, z = 22; FWE-corrected P = .02) during the processing of the NoGo compared to neutral stimuli, while presenting a decreased volume in the right inferior frontal gyrus. These findings were obtained irrespective of the adjustment of confounders, ADHD symptoms, and novelty seeking. There was an inverse relationship between inferior frontal gyrus activity and ADHD symptoms and between anterior cingulate cortex activity and novelty seeking. CONCLUSIONS AND RELEVANCE: These findings point to a functional involvement of prenatal exposure to tobacco smoke in neural alterations similar to ADHD, which underlines the importance of smoking prevention treatments

Early maternal care may counteract familial liability for psychopathology in the reward circuitry

Reward processing is altered in various psychopathologies and has been shown to be susceptible to genetic and environmental influences. Here, we examined whether maternal care may buffer familial risk for psychiatric disorders in terms of reward processing. Functional magnetic resonance imaging during a monetary incentive delay task was acquired in participants of an epidemiological cohort study followed since birth (N = 172, 25 years). Early maternal stimulation was assessed during a standardized nursing/playing setting at the age of 3 months. Parental psychiatric disorders (familial risk) during childhood and the participants’ previous psychopathology were assessed by diagnostic interview. With high familial risk, higher maternal stimulation was related to increasing activation in the caudate head, the supplementary motor area, the cingulum and the middle frontal gyrus during reward anticipation, with the opposite pattern found in individuals with no familial risk. In contrast, higher maternal stimulation was associated with decreasing caudate head activity during reward delivery and reduced levels of attention deficit hyperactivity disorder (ADHD) in the high-risk group. Decreased caudate head activity during reward anticipation and increased activity during delivery were linked to ADHD. These findings provide evidence of a long-term association of early maternal stimulation on both adult neurobiological systems of reward underlying externalizing behavior and ADHD during development

Association between pubertal stage at first drink and neural reward processing in early adulthood

Puberty is a critical time period during human development. It is characterized by high levels of risk-taking behavior, such as increased alcohol consumption, and is accompanied by various neurobiological changes. Recent studies in animals and humans have revealed that the pubertal stage at first drink (PSFD) significantly impacts drinking behavior in adulthood. Moreover, neuronal alterations of the dopaminergic reward system have been associated with alcohol abuse or addiction. This study aimed to clarify the impact of PSFD on neuronal characteristics of reward processing linked to alcohol-related problems. One hundred sixty-eight healthy young adults from a prospective study covering 25 years participated in a monetary incentive delay task measured with simultaneous EEG-fMRI. PSFD was determined according to the age at menarche or Tanner stage of pubertal development, respectively. Alcohol-related problems in early adulthood were assessed with the Alcohol Use Disorder Identification Test (AUDIT). During reward anticipation, decreased fMRI activation of the frontal cortex and increased preparatory EEG activity (contingent negative variation) occurred with pubertal compared to postpubertal first alcohol intake. Moreover, alcohol-related problems during early adulthood were increased in pubertal compared to postpubertal beginners, which was mediated by neuronal activation of the right medial frontal gyrus. At reward delivery, increased fMRI activation of the left caudate and higher feedback-related EEG negativity were detected in pubertal compared to postpubertal beginners. Together with animal findings, these results implicate PSFD as a potential modulator of psychopathology, involving altered reward anticipation. Both PSFD timing and reward processing might thus be potential targets for early prevention and intervention

Interaction between prenatal stress and dopamine D4 receptor genotype in predicting aggression and cortisol levels in young adults

RATIONALE: Considerable evidence suggests that genetic factors combine with environmental influences to impact on the development of aggressive behavior. A genetic variant that has repeatedly been reported to render individuals more sensitive to the presence of adverse experiences, including stress exposure during fetal life, is the seven-repeat allele of the dopamine D4 receptor (DRD4) gene. OBJECTIVES: The present investigation concentrated on the interplay of prenatal maternal stress and DRD4 genotype in predicting self-reported aggression in young adults. As disruption of the hypothalamic-pituitary-adrenal system has been discussed as a pathophysiological pathway to aggression, cortisol stress reactivity was additionally examined. METHODS: As part of an epidemiological cohort study, prenatal maternal stress was assessed by maternal interview 3 months after childbirth. Between the ages of 19 and 23 years, 298 offspring (140 males, 158 females) completed the Young Adult Self-Report to measure aggressive behavior and were genotyped for the DRD4 gene. At 19 years, 219 participants additionally underwent the Trier Social Stress Test to determine cortisol reactivity. RESULTS: Extending earlier findings with respect to childhood antisocial behavior, the results revealed that, under conditions of higher prenatal maternal stress, carriers of the DRD4 seven-repeat allele displayed more aggression in adulthood (p = 0.032). Moreover, the same conditions which seemed to promote aggression were found to predict attenuated cortisol secretion (p = 0.028). CONCLUSIONS: This is the first study to indicate a long-term impact of prenatal stress exposure on the cortisol stress response depending on DRD4 genotype