Faculty Bibliography

Reviews the book, Scattered Minds: Hope and Help for Adults With Attention Deficit Hyperactivity Disorder by Lenard Adler and Mari Florence (2006). The authors have written a nuts-and-bolts primer on adult ADHD for anyone who wants to know more about this relatively common condition. Many people do not know they have this disorder because they were not diagnosed as kids and their lives are in disarray. These are the people Adler is trying to reach through his book, one that contains basic straightforward information about adult ADHD for professionals and patients alike. Ever the optimist, Adler emphasizes the need for early diagnosis and treatment, a familiar approach for those of us who evaluate and treat children and adolescents. It is a slender book that cuts to the chase, something that is sure to appeal to most readers, especially those with ADHD. His book does, however, contain a few nonfatal irritants. The neuroimaging figures that the authors cite were reprinted in black and white and lack the dramatic clarity color provided in contrasting the brains of subjects with ADHD from normal controls as they appeared in the original articles in Biological Psychiatry. There were a few editorial glitches that should be corrected in future editions. Although both a strength and a weakness, the authors' take-home messages might be construed as repetitious but necessary for any would-be ADHD adult to absorb.

A heightened propensity for risk-taking and poor decision-making underlies the peak morbidity and mortality rates reported during adolescence. Delayed maturation of cortical structures during the adolescent years has been proposed as a possible explanation for this observation. Here, we test the hypothesis of adolescent delayed maturation by using fMRI during a monetary decision-making task that directly examines risk-taking behavior during choice selection. Orbitofrontal/ventrolateral prefrontal cortex (OFC/VLPFC) and dorsal anterior cingulate cortex (ACC) were examined selectively since both have been implicated in reward-related processes, cognitive control, and resolution of conflicting decisions. Group comparisons revealed greater activation in the OFC/VLPFC (BA 47) and dorsal ACC (BA 32) in adults than adolescents when making risky selections. Furthermore, reduced activity in these areas correlated with greater risk-taking performance in adolescents and in the combined group. Consistent with predictions, these results suggest that adolescents engage prefrontal regulatory structures to a lesser extent than adults when making risky economic choices.

BACKGROUND: Although comorbid anxiety disorders are common in children with bipolar disorder (BD), it is unclear how this comorbidity impacts the pathophysiology of the illness. METHODS: Pediatric BD with lifetime anxiety (BD+ANX, n = 20), BD without lifetime anxiety (BD-ANX, n = 11), and controls (n = 14) were administered the visual-probe paradigm, which assesses attention bias to threat faces. RESULTS: Bipolar disorder +ANX demonstrated a stronger bias toward threat relative to BD-ANX and controls; the latter two did not differ from each other. CONCLUSIONS: Bipolar disorder +ANX showed a bias toward threat while, in two previous studies, anxious children showed a bias away from threat faces. Future studies should compare the pathophysiology of BD with and without a comorbid anxiety disorder and anxiety disorders presenting alone.

Smaller hippocampal volume is associated with psychiatric disorders. Variations in hippocampal volume are discussed as both a consequence of the neurotoxic effects of stress and as a pre-existing condition leading to increased vulnerability for cognitive and emotional impairments. To investigate whether early experience can account for variability in hippocampal volume in adulthood (vulnerability hypothesis), we assessed the relationship between birth weight and hippocampal volume in 44 subjects. The reported quality of maternal care in early childhood, as evaluated by the Parental Bonding Inventory, was used as index of the quality of the postnatal environment. Hippocampal volume was assessed from magnetic resonance images using a manual segmentation protocol. We show that birth weight significantly predicts hippocampal volume in adulthood only in female subjects reporting low maternal care. The results suggest that the postnatal environment modulates the neurodevelopmental consequences of prenatal risk and that this effect is sex-specific

BACKGROUND: Much has been theorized about the emotional properties of the hemispheres. Our review of the dominant hypotheses put forth by Schore, Joseph, Davidson, and Harmon-Jones on hemispheric emotional valences (HEV) shows that none are supported by robust data. Instead, we propose that individual's hemispheres are organized to have differing HEVs that can be lateralized in either direction. METHODS: Probe auditory evoked potentials (AEP) recorded during a neutral and an upsetting memory were used to assess HEV in 28 (20 F) right-handed subjects who were either victims of childhood maltreatment (N = 12) or healthy controls. In a sub-population, we determined HEV by emotional response to lateral visual field stimulation (LVFS), in which vision is limited to one, then the other hemifield. We compare a number of morphometric and functional brain measures between individuals who have right-negative versus left-negative HEV. RESULTS: Using AEPs to determine HEV, we found 62% of controls and 67% of maltreated subjects had right negative HEV. There was a strong interaction between HEV-laterality and gender, which together accounted for 60% of individual variability in total grey matter volume (GMV). HEV-laterality was associated with differences in hippocampal volume, amygdala/hippocampal ratios, and measures of verbal, visual and global memory. HEV-laterality was associated also with different constellations of symptoms comparing maltreated subjects to controls. Emotional response to LVFS provided a convenient and complementary measure of HEV-laterality that correlated significantly with the HEVs determined by AEPs. CONCLUSION: Our findings suggest that HEV-laterality, like handedness or gender, is an important individual difference with significant implications for brain and behavioral research, and for guiding lateralized treatments such as rTMS

BACKGROUND: Although abnormalities in reward processing have been proposed to underlie attention-deficit/hyperactivity disorder (ADHD), this link has not been tested explicitly with neural probes. METHODS: This hypothesis was tested by using fMRI to compare neural activity within the striatum in individuals with ADHD and healthy controls during a reward-anticipation task that has been shown previously to produce reliable increases in ventral striatum activity in healthy adults and healthy adolescents. Eleven adolescents with ADHD (5 off medication and 6 medication-naive) and 11 healthy controls (ages 12-17 y) were included. Groups were matched for age, gender, and intelligence quotient. RESULTS: We found reduced ventral striatal activation in adolescents with ADHD during reward anticipation, relative to healthy controls. Moreover, ventral striatal activation was negatively correlated with parent-rated hyperactive/impulsive symptoms across the entire sample. CONCLUSIONS: These findings provide neural evidence that symptoms of ADHD, and impulsivity or hyperactivity in particular, may involve diminished reward anticipation, in addition to commonly observed executive dysfunction

BACKGROUND: Parental beliefs about child problem behaviour have emerged as closely related to referral intentions to mental health services. METHODS: This study compared beliefs of severity, impact and advice seeking for attention deficit/hyperactivity disorder (ADHD) behaviours of parents whose preschool children present ADHD behaviours with those of parents whose children do not display such behaviours. Both parents of 295 preschoolers, aged 4-6 years, enrolled in kindergartens in Athens, filled in: (i) a questionnaire composed by a vignette describing a hypothetical 5-year-old child presenting ADHD symptoms followed by rating scales assessing dimensions of severity, impact and referral intention, and (ii) the 'Strengths and Difficulties Questionnaire' for screening ADHD behaviours in their own child. RESULTS: Results showed that almost half of the parents who reported ADHD behaviours in their own child replied that they had never met a child exhibiting such behaviours. These parents also perceived such behaviours as being less severe and with less negative family impact than parents who did not report such behaviours in their own child. CONCLUSIONS: Parents whose preschool child displays ADHD behaviours tend to perceive them as normal developmental patterns and may suspend the referral of the child. Implications of these findings for early identification of ADHD are discussed

The effect of a course of electroconvulsive therapy (ECT) on blood pressure control in hypertensive patients has not been studied. We retrospectively examined pre- and post-ECT blood pressures in hypertensive and nonhypertensive patients. In neither group was there a statistically significant change in blood pressure with a course of ECT. We conclude that a course of ECT does not worsen blood pressure in hypertensive patients beyond the peritreatment period.

Multiple theories of Attention-Deficit/Hyper-activity Disorder (ADHD) have been proposed, but one that has stood the test of time is the dopamine deficit theory. We review the narrow literature from recent brain imaging and molecular genetic studies that has improved our understanding of the role of dopamine in manifestation of symptoms of ADHD, performance deficits on neuropsychological tasks, and response to stimulant medication that constitutes the most common treatment of this disorder. First, we consider evidence of the presence of dopamine deficits based on the recent literature that (1) confirms abnormalities in dopamine-modulated frontal-striatal circuits, reflected by size (smaller-than-average components) and function (hypoactivation); (2) clarifies the agonist effects of stimulant medication on dopaminergic mechanisms at the synaptic and circuit level of analysis; and (3) challenges the most-widely accepted ADHD-related neural abnormality in the dopamine system (higher-than-normal dopamine transporter [DAT] density). Second, we discuss possible genetic etiologies of dopamine deficits based on recent molecular genetic literature, including (1) multiple replications that confirm the association of ADHD with candidate genes related to the dopamine receptor D4 (DRD4) and the DAT; (2) replication of differences in performance of neuropsychological tasks as a function of the DRD4 genotype; and (3) multiple genome-wide linkage scans that demonstrate the limitations of this method when applied to complex disorders but implicate additional genes that may contribute to the genetic basis of ADHD. Third, we review possible environmental etiologies of dopamine deficits based on recent studies of (1) toxic substances that may affect the dopamine system in early development and contribute substantially to the etiology of ADHD; (2) fetal adaptations in dopamine systems in response to stress that may alter early development with lasting effects, as proposed by the developmental origins of health and disease hypothesis; and (3) gene-environment interactions that may moderate selective damage or adaptation of dopamine neurons. Based on these reviews, we identify critical issues about etiologic subtypes of ADHD that may involve dopamine, discuss methods that could be used to address these issues, and review old and new theories that may direct research in this area in the future