Inattention and hyperactivity-impulsivity: psychobiological and evolutionary underpinnings of ADHD

The impact of psychological theory on the treatment of Attention Deficit Hyperactivity Disorder (ADHD) in adults: A scoping review

Psychological theory and interpretation of research are key elements influencing clinical treatment development and design in Attention Deficit Hyperactivity Disorder (ADHD). Research-based treatment recommendations primarily support Cognitive Behavioural Therapy (CBT), an extension of the cognitive behavioural theory, which promotes a deficit-focused characterisation of ADHD and prioritises symptom reduction and cognitive control of self-regulation as treatment outcomes. A wide variety of approaches have developed to improve ADHD outcomes in adults, and this review aimed to map the theoretical foundations of treatment design to understand their impact. A scoping review and analysis were performed on 221 documents to compare the theoretical influences in research, treatment approach, and theoretical citations. Results showed that despite variation in the application, current treatments characterise ADHD from a single paradigm of cognitive behavioural theory. A single theoretical perspective is limiting research for effective treatments for ADHD to address ongoing issues such as accommodating context variability and heterogeneity. Research into alternative theoretical characterisations of ADHD is recommended to provide treatment design opportunities to better understand and address symptoms.

The effects of intranasal oxytocin in opioid-dependent individuals and healthy control subjects: a pilot study

RATIONALE

There has been an explosion of research on the potential benefits of the social neuropeptide oxytocin for a number of mental disorders including substance use disorders. Recent evidence suggests that intranasal oxytocin has both direct anti-addiction effects and pro-social effects that may facilitate engagement in psychosocial treatment for substance use disorders.

OBJECTIVES

We aimed to assess the tolerability of intranasal oxytocin and its effects on heroin craving, implicit association with heroin and social perceptual ability in opioid-dependent patients receiving opioid replacement therapy (ORT) and healthy control participants.

METHODS

We performed a randomized, double-blind, placebo-controlled, within- and between-subjects, crossover, proof-of-concept trial to examine the effects of oxytocin (40 international units) on a cue-induced craving task (ORT patients only), an Implicit Association Task (IAT), and two social perception tasks: the Reading the Mind in the Eyes Task (RMET) and The Awareness of Social Inference Test (TASIT).

RESULTS

Oxytocin was well tolerated by patients receiving ORT but had no significant effects on craving or IAT scores. There was a significant reduction in RMET performance after oxytocin administration versus placebo in the patient group only, and a significant reduction in TASIT performance after oxytocin in both the patient and healthy control groups.

CONCLUSIONS

A single dose of intranasal oxytocin is well tolerated by patients receiving ORT, paving the way for future investigations. Despite no significant improvement in craving or IAT scores after a single dose of oxytocin and some evidence that social perception was worsened, further investigation is required to determine the role oxytocin may play in the treatment of opioid use disorder.

CLINICAL TRIAL REGISTRATION

Methadone Oxytocin Option. ClinicalTrials.gov identifier: NCT01728909.

Common Cognitive Deficits in Children With Attention-Deficit/Hyperactivity Disorder and Autism

Cognitive deficits in working memory (WM) are characteristic features of Attention-Deficit/Hyperactivity Disorder (ADHD) and autism. However, few studies have investigated cognitive deficits using a wide range of cognitive measures. We compared children with ADHD ( n = 49) and autism ( n = 33) with a demographically matched control group ( n = 79) on a multidimensional battery of cognitive ability. Results confirmed previous research that both groups were characterized by deficits in WM. However, results also suggest verbal WM measures were better predictors than nonverbal WM measures. In addition, measures of visual-motor integration are equally discriminating of children with ADHD and autism from a matched control group. In all, 81% discrimination accuracy was obtained using only WM and visual-motor integration measures. Demonstrated shared deficits in WM and visual-motor integration are explained based on proposed neurological mechanisms common across the two disorders. Clinical implications are discussed.

Family-based association analysis of serotonin genes in pathological gambling disorder: evidence of vulnerability risk in the 5HT-2A receptor gene

Pathological gambling (PG) has become a growing public health problem in many countries around the world. PG is an impulse control disorder and its behavior and psychopathology present similarities with substance abuse disorders. Evidence from twin studies supports a significant genetic predisposition to PG, but the precise genetic loci still remain unclear. The present study investigates the allele and genotype distribution of polymorphisms of the serotonin transporter, serotonin receptor 1B and 2A genes in 140 sib-pairs discordant for the diagnosis of PG. A significant association of the C/C genotype of the serotonin receptor 2A T102C (rs 6313) polymorphism and the PG phenotype was observed [OR = 1.7 (1.1-3.4)]. This preliminary result is consistent with the hypothesis that the serotonin system is associated with addiction behavior and similar results have been reported for nicotine and alcohol dependence.

Severe pain predicts greater likelihood of subsequent suicide

Using data from the 1999 Large Health Survey of Veterans, Veterans Affairs' medical records, and the National Death Index (N = 260,254), the association between self-reported pain severity and suicide among veterans as examined, after accounting for demographic variables and psychiatric diagnoses. A Cox proportional hazards regression demonstrated that veterans with severe pain were more likely to die by suicide than patients experiencing none, mild, or moderate pain (HR: 1.33; 95% CI: 1.15, 1.54), after controlling for demographic and psychiatric characteristics. These results indicate that pain evaluations should be included in comprehensive suicide assessments and suicide prevention efforts.

Involvement of high plasma corticosterone status and activation of brain regional serotonin metabolism in long-term erythrosine-induced rearing motor hyper activity in young adult male rats

Long-term consumption of artificial food color(s) can induce behavioral hyperactivity in human and experimental animals, but no neurobiochemical mechanism is defined. This study investigates the role of brain regional serotonin metabolism including its turnover, MAO-A activity, and plasma corticosterone status in relation to behavioral disturbances due to an artificial food color, erythrosine. Long-term (15 or 30 consecutive days) erythrosine administration with higher dosage (10 or 100 mg/kg/day, p.o.) produced optimal hyperactive state in exploratory behavior (rearing motor activity) after 2 h of last erythrosine administration, in young adult male albino rats. Erythrosine-induced stimulation in brain regional (medulla-pons, hypothalamus, hippocampus, and corpus striatum) serotonin metabolism (measuring steady state levels of 5-HT and 5-HIAA, MAO-A activity), including its turnover (pargyline-induced 5-HT accumulation and 5-HIAA declination rate), as well as plasma corticosterone were also observed depending on dosage(s) and duration(s) of erythrosine administration under similar experimental conditions. The lower dosage of erythrosine (1 mg/kg/day, p.o.) under similar conditions did not affect either of the above. These findings suggests (a) the induction as well as optimal effect of long-term erythrosine (artificial food color) on behavioral hyperactivity in parallel with increase in 5-HT level in brain regions, (b) the activation of brain regional serotonin biosynthesis in accordance with plasma corticosterone status under such behavioral hyperactivity, and (c) a possible inhibitory influence of the enhanced glucocorticoids-serotonin interaction on erythrosine-induced rearing motor hyperactivity in young adult mammals.

The long-term effects of prenatal nicotine exposure on neurologic development

A large body of documented evidence has found that smoking during pregnancy is harmful to both the mother and the fetus. Prenatal exposure to nicotine in various forms alters neurologic development in experimental animals and may increase the risk for neurologic conditions in humans. There is a positive association between maternal smoking and sudden infant death syndrome (SIDS); however, the connection between nicotine addiction, depression, attention disorders, and learning and behavior problems in humans is not straightforward. Nicotine's action on the production and function of neurotransmitters makes it a prime suspect in the pathology of these diseases. Nicotine accentuates neurotransmitter function in adults but desensitizes these functions in prenatally exposed infants and children. This desensitization causes an abnormal response throughout the lifespan. Furthermore, nicotine use by adolescents and adults can alleviate some of the symptoms caused by these neurotransmitter problems while they increase the risk for nicotine addiction. Although nicotine replacement drugs are used by pregnant women, there is no clear indication that they improve outcomes during pregnancy, and they may add to the damage that occurs to the developing neurologic system in the fetus. Understanding the effects of nicotine exposure is important in providing safe care for pregnant women, children, and families and for developing appropriate smoking cessation programs during pregnancy.

Borderline personality disorder: toward integration

Several psychiatric disorders, including borderline personality disorder (BPD), are characterized by emotional dysregulation and impulse dyscontrol. More specifically, symptoms in patients with BPD often occur within the context of disruptions in attachment and related distortions in cognitive-affective processing of the self and others. From a neurocircuitry perspective, findings include prefrontal hypoactivity, amygdala hyperreactivity, and alterations in prefrontal-limbic interaction. Molecular pathways relevant to these circuits include the serotonergic, noradrenergic, and dopaminergic systems, and there is some evidence that pharmacotherapy with agents that act on these systems may be useful. Given the disruptions in attachment and schemas of the self and others in BPD, establishing a therapeutic alliance is crucial while psychotherapy remains the cornerstone of an integrated approach to management.

Excess of transmission of the G allele of the -1438A/G polymorphism of the 5-HT2A receptor gene in patients with schizophrenia responsive to antipsychotics

BACKGROUND

The -1438A/G polymorphism of the 5-HT2A gene has been found to be associated with clinical response to clozapine and other second generation antipsychotics. Testing the impact of this marker on response to first generation antipsychotics (which have a lower affinity for the 5-HT2A receptor) provides the opportunity to help disentangling the two different roles that this polymorphism might have. A psychopharmacogenetic role should be detected only for antipsychotics with high affinity to the 5-HT2A receptor (therefore to second generation antipsychotics). An alternative role would imply tagging a subgroup of patients responsive to any antipsychotic, whatever their affinity, meaning that the association is more depending on non pharmacological charaterictics, such as clinical specificities.

METHODS

A family-based sample of 100 Algerian patients with schizophrenia (according to DSM-IV criteria) and their 200 biological parents was recruited, in order to avoid stratification biases. Patients were all treated, or have been treated, by conventional antipsychotics (mainly haloperidol) for at least four weeks, at appropriate dosage. May and Dencker scale was used to distinguish responders and non responders.

RESULTS

No allele of the -1438A/G polymorphism of the 5-HT2A gene was transmitted in excess (50 transmitted for 38 untransmitted) in the whole sample of patients with schizophrenia (p = .90). In contrast, a significant excess of transmission of the G allele was observed (p = .02) in the subgroup of patients with good treatment response (17 transmitted for 6 untransmitted).

CONCLUSION

Using a TDT approach, we showed that the G allele of the -1438A/G polymorphism of the gene coding for the 5-HT2A receptor was associated to schizophrenia with good response to conventional antipsychotics, although this conclusion is based on 88 informative patients only. Because previous data showed the same result with atypical antipsychotics, it can be concluded that the G allele tags a subgroup of schizophrenic patients with greater chance of improvement with antipsychotics of either type.

Prefrontal serotonergic denervation induces increase in the density of 5-HT2A receptors in adult rat prefrontal cortex

The 5-HTergic system and particularly 5-HT(2A) receptors have been involved in prefrontal cognitive functions, but the underlying mechanisms by which the serotonin (5-HT) system modulates these processes are still unclear. In this work, the effects of prefrontal 5-HTergic denervation on the density and expression levels of 5-HT(2A) receptors were evaluated by immunohistochemical and molecular biology studies in the prefrontal cortex (PFC). The [(3)H]-Ketanserin binding study revealed an increase in the B(max), along with no change in the binding affinity (K(D)) for 5-HT(2A) receptors. The increase in PFC of 5-HT(2A) receptor density in response to denervation was accompanied by increase in 5-HT(2A) receptor mRNA and protein levels. This increase in the number of 5-HT(2A) receptors may be interpreted as an adaptive plastic change, i.e., hypersensitivity; resulting from the selective pharmacological lesion of the raphe-proceeding 5-HTergic fibers to the PFC. Based on previous evidence, this could be strongly related to the abnormal expression of short-term memory.

Mindfulness meditation training in adults and adolescents with ADHD: a feasibility study

OBJECTIVE

ADHD is a childhood-onset psychiatric condition that often continues into adulthood. Stimulant medications are the mainstay of treatment; however, additional approaches are frequently desired. In recent years, mindfulness meditation has been proposed to improve attention, reduce stress, and improve mood. This study tests the feasibility of an 8-week mindfulness training program for adults and adolescents with ADHD.

METHOD

Twenty-four adults and eight adolescents with ADHD enrolled in a feasibility study of an 8-week mindfulness training program.

RESULTS

The majority of participants completed the training and reported high satisfaction with the training. Pre-post improvements in self-reported ADHD symptoms and test performance on tasks measuring attention and cognitive inhibition were noted. Improvements in anxiety and depressive symptoms were also observed.

CONCLUSION

Mindfulness training is a feasible intervention in a subset of ADHD adults and adolescents and may improve behavioral and neurocognitive impairments. A controlled clinical study is warranted.