There has been increasing knowledge of the treatment, diagnosis, and demographics of adults with residual attention deficit/hyperactivity disorder (ADHD). However, less is known about the ...neuropsychological functioning in adults with residual ADHD. In comparing the clinical neuropsychological test performance of a group of adult clinic patients with residual ADHD (N = 30) with that of normal controls (N = 10), we found the patients performed worse on the Trail Making Test, a visual continuous performance test, and the "Brown-Peterson" Auditory Consonant Trigrams Test, but not on any other neuropsychological measures. This pattern indicated a deficit in the area of executive control type functioning, a functional deficit that could be linked to dysregulation of frontal lobe brain systems. Of equal interest was that patients diagnosed with ADHD/hyperactive impulsive type (ADHD+) and patients diagnosed with ADHD/inattentive type (ADHD−) had different types of executive system deficits. ADHD+ was associated with relative deficiency on the Wisconsin Card Sorting Test. ADHD− was associated with relative deficiency on the "Brown-Peterson" Auditory Consonant Trigrams Test, a measure of working memory, as well as less olfactory identification on a smell identification test. The data are discussed in terms of recent localization theories of frontal lobe function. The preliminary data suggest that the different cognitive weaknesses of ADD subtypes may be linked to dysregulation of separate frontal brain regions and/or neurotransmitter systems.
Abstract
Objective: Bipolar and Schizophrenia Network for Intermediate Phenotypes (B-SNIP) researchers have proposed three Biotypes that show advantages of a dimensional approach to classification, ...revealing different levels of dysfunction severity through EEG and various forms of cognitive testing. Although preliminary work has been done showing neuroanatomical differences among the biotypes and patterns of heredity, more research is required to investigate the contribution of significant co-morbid factors such as alcohol misuse. Objective. Neuroanatomical data were used to further understand the biomarker of grey matter volume (GMV) in relation to the B-SNIP Biotypes and the interacting influence of family history of alcohol use disorder (FH-AUD).
Method. Biotype, FH-AUD, and demographic variables (age, sex, education, and ethnicity) were used in hierarchical regression analyses for prediction of total volume and two key regions (superior parietal cortex and posterior cingulate cortex) in stable probands (n = 347) and their healthy first-degree relatives (n = 346) separately. Prediction was also analyzed in the context of conventional diagnosis of psychotic disorders (schizophrenia, schizoaffective disorder, and bipolar disorder with psychotic features). Structural data were analyzed using FreeSurfer.
Results. Biotype was shown to be a more robust predictor of GMV than diagnosis both generally and specifically in relevant regions (p < .05). A pattern of GMV reduction based on severity was observed both in probands and relatives. Effects of FH-AUD and its interaction with Biotype were occasionally observed.
Conclusions. This study contributes to the efforts of psychobiological research to establish a more valid conceptualization of psychological disorders through biological mechanisms.
The Test of Memory Malingering (TOMM; T. N.
Tombaugh, 1996
) is a newly developed visual recognition test that uses pictures of common objects as stimuli. Prior normative research with ...community-dwelling adults and neurologically impaired patients has shown that the TOMM possesses a high degree of specificity and is not affected by demographic variables such as age and education. The current series of 5 integrated experiments was designed to provide important validation data. Converging evidence from all studies showed that scores on the TOMM are able to detect when an individual is not putting forth maximum effort. Overall, the TOMM's high levels of sensitivity and specificity suggest that it has high promise as a clinical test for detecting malingering of memory impairments.
The objective of this study is to determine whether violence in psychiatric patients is associated with brain dysfunction independent of substance abuse. Psychiatric inpatients with a history of ...violent behavior in the community were compared to nonviolent inpatients on several variables related to brain dysfunction. The two groups were similar in terms of demographics and psychiatric diagnosis. No significant differences were found in neuropsychological function, but violent patients were significantly more likely to have co-occurring substance abuse and nearly 4 times more likely to have a history of closed-head injury. Logistic regression revealed that the association between violence and head injury can be explained by comorbid substance abuse.
According to bottom-up/top-down models, impulsivity facets are represented across the cerebral cortex and subcortex. Hypothesized gray matter correlates of motor, attentional and non-planning ...impulsivity were examined in groups of 35 psychiatric patients characterized by self-control problems and 18 healthy volunteers. Among patients, a positive correlation was found between motor impulsivity and the right cerebellum, and a negative correlation emerged between attentional impulsivity and the left lateral orbitofrontal cortex (OFC). Among controls, attentional and motor impulsivity correlated negatively with the left superior temporal gyrus, while non-planning impulsivity correlated positively with the left OFC and lateral frontopolar cortex. Follow-up analyses revealed convergence in correlation patterns from patients to controls, but not vice versa. That pattern suggested broader neural representation of the trait in the healthy controls, who were less impulsive than the psychiatric patients.
Alcoholism and antisocial personality disorder (ASPD) often are comorbid conditions. Alcoholics, as well as nonalcoholic individuals with ASPD, exhibit behaviors associated with prefrontal brain ...dysfunction such as increased impulsivity and emotional dysregulation. These behaviors can influence drinking motives and patterns of consumption. Because few studies have investigated the combined association between ASPD and alcoholism on neuropsychological functioning, this study examined the influence of ASPD symptoms and alcoholism on tests sensitive to frontal brain deficits. The participants were 345 men and women. Of them, 144 were abstinent alcoholics (66 with ASPD symptoms), and 201 were nonalcoholic control participants (24 with ASPD symptoms). Performances among the groups were examined with Trails A and B tests, the Wisconsin Card Sorting Test, the Controlled Oral Word Association Test, the Ruff Figural Fluency Test, and Performance subtests of the Wechsler Adult Intelligence Scale. Measures of affect also were obtained. Multiple regression analyses showed that alcoholism, specific drinking variables (amount and duration of heavy drinking), and ASPD were significant predictors of frontal system and affective abnormalities. These effects were different for men and women. The findings suggested that the combination of alcoholism and ASPD leads to greater deficits than the sum of each.
The present study collected preliminary data testing the hypothesis that a lengthy transcranial direct current stimulation (tDCS) protocol reduces obsessive-compulsive disorder symptoms and ...strengthens executive control. Five patients presenting with treatment-resistant obsessive-compulsive disorder (TR-OCD) underwent neurocognitive and clinical testing prior to (baseline assessment) and after completing three weeks of tDCS (post-treatment evaluation). Four TR-OCD patients participated in 15 daily tDCS sessions during the three-week trial. One patient participated in 13 sessions. Scalp electrodes were situated using the standard montage for DLPFC stimulation: anode over left DLPFC (F3) and cathode over right frontopolar region (Fp2). We gained significant insights with this extensive testing: (1) TR-OCD patients demonstrated significant OCD symptom reduction following the course of tDCS; however, gains were not maintained at 1-month follow-up; (2) there were changes in depressive and schizotypal (positive) symptoms following three weeks of tDCS; however, baseline/post-treatment differences did not reach significance; (3) TR-OCD patients significantly lowered their daily ratings of depressive and generalized anxiety symptoms; (4) TR-OCD patients obtained a significant and specific improvement in Trail Making Test-part B (TMT-B) performance; and (5) there was a significant and robust correlation between TMT-B improvement and OCD symptom reduction. Although practice and placebo effects cannot be ruled out, the specific effects found in the study support further testing in a randomized controlled trial. Our results provide data to design further randomized clinical trials as to test whether and how tDCS induces a relevant clinical benefit in OCD. We discuss important design considerations for such a trial.
The assumption that voxel-based morphometry (VBM) offers an automated substitution for manually-traced volumetry was subjected to empirical evaluation. Data available from a previous volumetry study ...(Gansler et al. Psychiatry Research: Neuroimaging 171:145-154, 2009) provided the basis for the current study, which assessed for convergence between the methods. Optimized modulated VBM was used to preprocess images (N = 40). Gray matter volume and self-reported aggression associations were tested. Results indicate convergence, as both methods revealed significant negative associations of the left orbitofrontal cortex (OFC) and aggression. VBM detected an additional positive left OFC result not revealed with volumetry, suggesting that VBM may allow greater within-region localization than volumetry. However, the methods differentially deal with error rates and power demands and as such are better conceptualized as complementary than interchangeable.
The prefrontal cortex (PFC) is the seat of higher level control operations, with recognition and working memory processes critical to those operations. While not strictly organized by the principle ...of localization, certain functions are clearly more associated with one region than another within PFC dynamic systems. We set out to test the hypothesis that active visual memory comparison (making judgments of novelty) was most associated with the ventrolateral prefrontal cortex (VLPFC), while the monitoring and manipulation of visual information was most associated with the mid-dorsolateral prefrontal cortex (mid-DLPFC). The current study used magnetic resonance volumetry to define the VLPFC and mid-DLPFC as regions of interest (ROIs), and analyzed those in relation to types of visual memory processes. We observed a functional dissociation of working memory within the PFC corresponding to comparison versus monitoring processes. One of the blocks of the monitoring and manipulation task showed a significant positive relationship with left, right, and total mid-DLPFC volume, with no significant relationship to the VLPFC. Performance on a memory comparison task bore a significant positive relationship with right and total VLPFC volume, and no relationship with the mid-DLPFC.
PDF
