Early Maternal Care and Amygdala Habituation to Emotional Stimuli in Adulthood

Evidence suggests that maternal care constitutes a protective factor for psychopathology which may be conditional on the level of family adversity. Given that psychopathology is frequently linked with social deficits, and the amygdala with social functioning, we investigated the impact of early maternal care on amygdala function under high versus low familial risk for psychopathology. Amygdala activity and habituation during an emotional face-matching paradigm was analyzed in participants of an epidemiological cohort study followed since birth (N=172, 25 years). Early mother-infant interaction was assessed during a standardized nursing and play setting at the age of 3 months. Information on familial risk during the offspring's childhood and on the participants' lifetime psychopathology was obtained with diagnostic interviews. An interaction between maternal stimulation and familial risk was found on amygdala habituation but not on activation, with higher maternal stimulation predicting stronger amygdala habituation in the familial risk group only. Furthermore, amygdala habituation correlated inversely with ADHD diagnoses. The findings underline the long-term importance of early maternal care on the offspring´s socioemotional neurodevelopment and of interventions targeting maternal sensitivity early in life, particularly by increasing maternal interactive behavior in those with familial risk.

Neural reward processing in paediatric Tourette syndrome and/or attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is the most common comorbidity in individuals with Tourette syndrome (TS). Yet, it is unclear to what extent TS and ADHD show overlapping or distinct neural abnormalities. ADHD has been associated with altered reward processing, but there are very few studies on reward processing in TS. This study assessed neural activation of basal ganglia and thalamus during reward anticipation and receipt in children with TS and/or ADHD. We analysed mean activations of a priori specified regions of interest during an fMRI monetary incentive delay task. Data was used from 124 children aged 8-12 years (TS n = 47, of which 29 had comorbid ADHD; ADHD n = 29; healthy controls n = 48). ADHD severity across ADHD and TS groups and healthy controls was marginally related to hypoactivation of the right nucleus accumbens during reward anticipation; this effect was not moderated by TS diagnosis. We detected no associations of neural activation with TS. The association between ADHD severity and hypoactivation of the right nucleus accumbens during reward anticipation, independent of the presence or absence of TS, is in line with the view of nucleus accumbens hypoactivation as a dimensional, neurofunctional marker of ADHD severity, transcending the boundaries of primary diagnosis.

Frontostriatal functional connectivity correlates with repetitive behaviour across autism spectrum disorder and obsessive-compulsive disorder

BACKGROUND

Autism spectrum disorder (ASD) and obsessive-compulsive disorder (OCD) are neurodevelopmental disorders with considerable overlap in terms of their defining symptoms of compulsivity/repetitive behaviour. Little is known about the extent to which ASD and OCD have common versus distinct neural correlates of compulsivity. Previous research points to potentially common dysfunction in frontostriatal connectivity, but direct comparisons in one study are lacking. Here, we assessed frontostriatal resting-state functional connectivity in youth with ASD or OCD, and healthy controls. In addition, we applied a cross-disorder approach to examine whether repetitive behaviour across ASD and OCD has common neural substrates.

METHODS

A sample of 78 children and adolescents aged 8-16 years was used (ASD n = 24; OCD n = 25; healthy controls n = 29), originating from the multicentre study COMPULS. We tested whether diagnostic group, repetitive behaviour (measured with the Repetitive Behavior Scale-Revised) or their interaction was associated with resting-state functional connectivity of striatal seed regions.

RESULTS

No diagnosis-specific differences were detected. The cross-disorder analysis, on the other hand, showed that increased functional connectivity between the left nucleus accumbens (NAcc) and a cluster in the right premotor cortex/middle frontal gyrus was related to more severe symptoms of repetitive behaviour.

CONCLUSIONS

We demonstrate the fruitfulness of applying a cross-disorder approach to investigate the neural underpinnings of compulsivity/repetitive behaviour, by revealing a shared alteration in functional connectivity in ASD and OCD. We argue that this alteration might reflect aberrant reward or motivational processing of the NAcc with excessive connectivity to the premotor cortex implementing learned action patterns.

The Long-Term Impact of Early Life Stress on Orbitofrontal Cortical Thickness

Early adversity has been related to brain structure alterations and to an increased risk of psychiatric disorders. The orbitofrontal cortex (OFC) is a key region for emotional processing, with structural alterations being described in several mental disorders. However, little is known about how its cortical thickness (CT) is affected by the long-term impact of life stress (LS) at different developmental stages. The present study aimed to investigate the effect of LS during infancy, childhood, and adolescence on CT alterations in the OFC and on psychopathology in 190 adults of an ongoing prospective cohort study. Chronic stressful life events were assessed in regular intervals. Participants rated depressive symptoms at the ages of 22 and 23 years. Morphometric data were collected at the participants’ age of 25 years. Chronic LS during infancy was associated with reduced CT in the right OFC and increased depressive symptoms. Moreover, the impact of chronic LS during infancy on OFC thickness was partially mediated by depressive symptoms in adulthood, suggesting an interplay of early LS, psychopathology, and CT alterations. Our findings highlight the long-term impact of early LS on an affective core brain structure and psychopathology later in life.

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.

Fronto-Striatal Glutamate in Autism Spectrum Disorder and Obsessive Compulsive Disorder

This corrects the article DOI: 10.1038/npp.2016.260.

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.

Ventral striatum and amygdala activity as convergence sites for early adversity and conduct disorder

Childhood family adversity (CFA) increases the risk for conduct disorder (CD) and has been associated with alterations in regions of affective processing like ventral striatum (VS) and amygdala. However, no study so far has demonstrated neural converging effects of CFA and CD in the same sample. At age 25 years, functional MRI data during two affective tasks, i.e. a reward (N = 171) and a face-matching paradigm (N = 181) and anatomical scans (N = 181) were acquired in right-handed currently healthy participants of an epidemiological study followed since birth. CFA during childhood was determined using a standardized parent interview. Disruptive behaviors and CD diagnoses during childhood and adolescence were obtained by diagnostic interview (2-19 years), temperamental reward dependence was assessed by questionnaire (15 and 19 years).CFA predicted increased CD and amygdala volume. Both exposure to CFA and CD were associated with a decreased VS response during reward anticipation and blunted amygdala activity during face-matching. CD mediated the effect of CFA on brain activity. Temperamental reward dependence was negatively correlated with CFA and CD and positively with VS activity. These findings underline the detrimental effects of CFA on the offspring's affective processing and support the importance of early postnatal intervention programs aiming to reduce childhood adversity factors.

Neurofeedback Training Effects on Inhibitory Brain Activation in ADHD: A Matter of Learning?

Neurofeedback training (NF) is a promising non-pharmacological treatment for ADHD that has been associated with improvement of attention-deficit/hyperactivity disorder (ADHD)-related symptoms as well as changes in electrophysiological measures. However, the functional localization of neural changes following NF compared to an active control condition, and of successful learning during training (considered to be the critical mechanism for improvement), remains largely unstudied. Children with ADHD (N=16, mean age: 11.81, SD: 1.47) were randomly assigned to either slow cortical potential (SCP, n=8) based NF or biofeedback control training (electromyogram feedback, n=8) and performed a combined Flanker/NoGo task pre- and post-training. Effects of NF, compared to the active control, and of learning in transfer trials (approximating successful transfer to everyday life) were examined with respect to clinical outcome and functional magnetic resonance imaging (fMRI) changes during inhibitory control. After 20 sessions of training, children in the NF group presented reduced ADHD symptoms and increased activation in areas associated with inhibitory control compared to baseline. Subjects who were successful learners (n=9) also showed increased activation in an extensive inhibitory network irrespective of the type of training. Activation increased in an extensive inhibitory network following NF training, and following successful learning through NF and control biofeedback. Although this study was only powered to detect large effects and clearly requires replication in larger samples, the results suggest a crucial role for learning effects in biofeedback trainings.

Interacting effect of MAOA genotype and maternal prenatal smoking on aggressive behavior in young adulthood

Findings on the etiology of aggressive behavior have provided evidence for an effect both of genetic factors, such as variation in the monoamine oxidase A (MAOA) gene, and adverse environmental factors. Recent studies have supported the existence of gene × environment interactions, with early experiences playing a key role. In the present study, the effects of prenatal nicotine exposure, MAOA genotype and their interaction on aggressive behavior during young adulthood were examined. In a sample of 272 young adults (129 males, 143 females) from an epidemiological cohort study, smoking during pregnancy was measured with a standardized parent interview at the offspring's age of 3 months. Aggressive behavior was assessed between the ages of 19 and 25 years using the Young Adult Self-Report. DNA was genotyped for the MAOA 5' untranslated region variable number of tandem repeats polymorphism (VNTR). Results revealed a significant interaction between MAOA and smoking during pregnancy, indicating higher levels of aggressive behavior in young adults carrying the MAOA low-expressing genotype who had experienced prenatal nicotine exposure (n = 8, p = .025). In contrast, in carriers of the MAOA high-expressing genotype, maternal smoking during pregnancy had no effect on aggressive behavior during young adulthood (n = 20, p = .145). This study extends earlier findings demonstrating an interaction between MAOA genotype and prenatal nicotine exposure on aggressive behavior into young adulthood. The results point to the long-term adverse effects of smoking during pregnancy on the offspring's mental health, possibly underlining the importance of smoking cessation during pregnancy. According to the nature of the study (particularly sample size and power), analyses are exploratory and results need to be interpreted cautiously.