Neurobiological Basis of Reinforcement-Based Decision-Making in Adults With ADHD Treated With Lisdexamfetamine Dimesylate

Background: The objective of this study was to examine changes in the activation of the brain reward system following treatment with lisdexamfetamine (LDX) vs. placebo (PL) as a function of clinical improvement in attention deficit/hyperactivity disorder (ADHD) symptoms. Methods: Twenty adults with ADHD were included in a randomized cross-over study. Participants underwent two functional magnetic resonance imaging (fMRI) scans, after receiving 3 to 5 weeks of treatment with both LDX and PL. During scanning, participants performed the passive-avoidance learning task to assess reward-related learning using computational variables (e.g., estimated value and prediction error). Pre-treatment to post-treatment symptom change was assessed via the ADHD Rating Scale (ADHD-RS). The imaging contrasts were Object Choose or Object Refuse during the object choice component of the task, modulated by expected value (reward vs. nonreward cue), and Reward vs. Punishment during feedback, modulated by prediction error (expected vs. actual outcome). To address the primary objective, we performed group-level mass univariate analyses between pre-treatment to post-treatment percent change of the ADHD-RS total scores and the four contrast images under the choice and feedback conditions, with significance set at a whole-brain voxel-wise threshold of p < .05 with family-wise error (FWE) correction and an extent (cluster) threshold of 50 contiguous voxels. Results: Improvement in ADHD symptoms was accompanied by significant increases of brain activation during the Object Refuse, Reward and Punishment contrasts in a widespread network including left caudate and putamen, and right orbitofrontal cortex (i.e., reward-related signaling) and left middle frontal, superior frontal, and precentral gyri (i.e., executive control). Conclusions: These findings are the first to show that the increase in responsiveness of systems engaged in reward processing with LDX treatment is positively related to symptom improvement. Results support the hypothesis that LDX treatment may restore balance to dysfunction (e.g., hypoactivation) within the brain reward circuitry in adults with ADHD.

The effects of temporally secondary co-morbid mental disorders on the associations of DSM-IV ADHD with adverse outcomes in the US National Comorbidity Survey Replication Adolescent Supplement (NCS-A)

BACKGROUND

Although DSM-IV attention deficit hyperactivity disorder (ADHD) is known to be associated with numerous adverse outcomes, uncertainties exist about how much these associations are mediated temporally by secondary co-morbid disorders.

METHOD

The US National Comorbidity Survey Replication Adolescent Supplement (NCS-A), a national survey of adolescents aged 13-17 years (n = 6483 adolescent-parent pairs), assessed DSM-IV disorders with the World Health Organization (WHO) Composite International Diagnostic Interview (CIDI). Statistical decomposition was used to compare direct effects of ADHD with indirect effects of ADHD through temporally secondary mental disorders (anxiety, mood, disruptive behavior, substance disorders) in predicting poor educational performance (suspension, repeating a grade, below-average grades), suicidality (ideation, plans, attempts) and parent perceptions of adolescent functioning (physical and mental health, interference with role functioning and distress due to emotional problems).

RESULTS

ADHD had significant gross associations with all outcomes. Direct effects of ADHD explained most (51.9-67.6%) of these associations with repeating a grade in school, perceived physical and mental health (only girls), interference with role functioning and distress, and significant components (34.5-44.6%) of the associations with school suspension and perceived mental health (only boys). Indirect effects of ADHD on educational outcomes were predominantly through disruptive behavior disorders (26.9-52.5%) whereas indirect effects on suicidality were predominantly through mood disorders (42.8-59.1%). Indirect effects on most other outcomes were through both mood (19.8-31.2%) and disruptive behavior (20.1-24.5%) disorders, with anxiety and substance disorders less consistently important. Most associations were comparable for girls and boys.

CONCLUSIONS

Interventions aimed at reducing the adverse effects of ADHD might profitably target prevention or treatment of temporally secondary co-morbid disorders.

Attention-deficit/hyperactivity disorder in adult patients with posttraumatic stress disorder (PTSD): is ADHD a vulnerability factor?

OBJECTIVE

There is limited evidence suggesting a link between posttraumatic stress disorder (PTSD) and Attention-Deficit/ Hyperactivity Disorder (ADHD). This study examined the association between PTSD and ADHD using retrospective and current clinical evaluations.

METHOD

Twenty-five male veterans with PTSD and 22 male veterans with panic disorder were evaluated for ADHD. The data was analyzed using chi-square and student's t-tests.

RESULTS

Thirty-six percent of participants with PTSD and 9% of participants with panic disorder met criteria for childhood ADHD. Twenty-eight percent of participants with PTSD and 5% of participants with panic disorder met criteria for current ADHD.

CONCLUSIONS

There appears to be a significant association of PTSD with ADHD. ADHD or common predisposing factors may increase the vulnerability for developing PTSD.

Akathisia and exacerbation of psychopathology: a preliminary report

Akathisia has previously been reported to exacerbate psychopathology and to be associated with noncompliance, suicidality, and violence. One previous study found brisk decrements in psychopathology after acute treatment of akathisia with intramuscular biperiden. This study assessed changes in akathisia and psychopathology in 19 patients after separate one-day treatments with intramuscular benztropine and oral propranolol. Benztropine and propranolol led to clinically meaningful and statistically significant decrements in ratings of subjective and objective measures of akathisia and in psychopathology scores. Changes in psychopathology correlated significantly with changes in subjective measures of akathisia after benztropine and with subjective and objective measures of akathisia after propranolol. Changes in akathisia accounted for 9%-42% of the variance in changes in psychopathology. After treatment, statistically significant decrements in Brief Psychiatric Rating Scale (BPRS) positive symptoms were noted, and individual items not directly related to the akathisia syndrome, such as conceptual disorganization, hallucinatory behavior, and unusual thought content declined, although not significantly. These findings, taken together with the results of a similar previous study, indicate that the effect of akathisia in exacerbating psychopathology is large. If suspected, akathisia should be treated promptly.

Vitamin E treatment for tardive dyskinesia. Veterans Affairs Cooperative Study #394 Study Group

BACKGROUND

Several short-term, controlled trials have documented the efficacy of vitamin E in treating tardive dyskinesia. However, the persistent nature of the disease prompted us to perform a multicenter, longer-term trial of vitamin E.

METHODS

The study was a prospective, randomized, 9-site trial of up to 2 years of treatment with d-vitamin E (1600 IU/d) vs matching placebo. One hundred fifty-eight subjects with tardive dyskinesia who were receiving neuroleptic medications were enrolled. The blinded assessments performed were clinical (Abnormal Involuntary Movements Scale, Barnes Akathisia Scale, and Modified Simpson-Angus [for Extrapyramidal Symptoms] Scale) and electromechanical assessments of movement disorders, psychiatric status (Brief Psychiatric Rating Scale), and functioning (Global Assessment of Functioning). There were no significant differences in baseline demographic characteristics or in study assessments between the group that received vitamin E and the group that received placebo.

RESULTS

Vitamin E was well tolerated and subject compliance with medication was good and similar between treatment groups. One hundred seven subjects (70% of those receiving vitamin E and 66% of subjects receiving placebo) completed at least 1 year of treatment. There were no significant effects of vitamin E on total scores or subscale scores for the AIMS, electromechanical measures of dyskinesia, or scores from the other 4 scales.

CONCLUSION

This long-term, randomized trial of vitamin E vs placebo found no evidence for efficacy of vitamin E in the treatment of tardive dyskinesia.

Long-term treatment effects of vitamin E for tardive dyskinesia

BACKGROUND

Several studies have found that alpha-tocopherol (vitamin E) can effectively treat tardive dyskinesia (TD). A limitation of these trials is their short treatment durations (maximum of 12 weeks), which do not allow us to address the effects of long-term treatment.

METHODS

To participate, patients had to have TD and be on stable oral medications. The study enrolled 40 patients who received up to 36 weeks of treatment with d-vitamin E (1600 IU per day) or placebo.

RESULTS

Using the Abnormal Involuntary Movements Scale (AIMS) score (sum of items #1-7) to measure TD severity, the study found a significant difference (3 points) in mean AIMS scores, in favor of vitamin E, starting at 10 weeks of treatment and continuing through the full 36 weeks. We used linear mixed-effects regression to quantify the impact of several covariates, and found that treatment assignment. TD duration, and chlorpromazine equivalents had significant effects on decreasing the AIMS score.

CONCLUSIONS

The study's finding that vitamin E is effective in treating TD agrees with results from prior studies and provides evidence that the effect may extend to treatment of up to 36 weeks. These findings are in direct contrast to those of VA Cooperative Study #394, a much larger, long-term, multi-site study, conducted by many of the same investigators, in which Vitamin E was not superior to placebo.

Interrater reliability issues in multicenter trials, Part II: Statistical procedures used in Department of Veterans Affairs Cooperative Study #394

The primary goal of Veterans Affairs (VA) Cooperative Study (CS) #394 is to determine if vitamin E is a safe and efficacious treatment for tardive dyskinesia (TD). The study uses various instruments to assess subjects for movement disorders (Abnormal Involuntary Movement Scale [AIMS], and Barnes Akathisia Scale [BAS]), psychopathology (Anchored Brief Psychiatric Rating Scale [BPRS]), and level of functioning (Global Assessment of Functioning scale [GAF]). Since the study involves nine sites, each with its own set of raters, it is important to establish and maintain high interrater reliability (IRR) on these instruments throughout the study and to identify raters who differ significantly from the others. To make this determination, personnel at each site assessed subjects from standardized videotapes on the AIMS, BAS, and Anchored BPRS, and rated written vignettes on the GAF. We fit these data to a two-way additive model to identify nonstandardized raters (i.e., those whose average ratings were significantly lower or higher than the others, or those whose scores, after adjusting for subject and rater effects, were highly variable). The proportion of nonstandardized raters ranged from 7 percent (Anchored BPRS) to 33 percent (AIMS). The estimated intraclass correlation coefficients (ICCs) indicated moderate reliability for the AIMS, BAS, and Anchored BPRS (0.73 to 0.75) and excellent agreement for the GAF (0.90). The companion article (Part I: Tracy et al. 1997, page 53 of this issue) describes the procedures used to train the raters for this study.

Interrater reliability issues in multicenter trials, Part I: Theoretical concepts and operational procedures used in Department of Veterans Affairs Cooperative Study #394

This article describes a standardized method for establishing and maintaining desired levels of interrater reliability (IRR) in multicenter trials. The procedure involves six steps: distribution of procedural guides, distribution of an introduction tape, initial distribution of patient interviews to rate, training at the study kickoff meeting, ongoing IRR monitoring, and group training throughout the study. This method is being used in a national Veterans Affairs Cooperative Study (CS #394), involving nine sites to examine the treatment effects of vitamin E on tardive dyskinesia. The six-step standardized process allowed for early detection of areas of concern in assessment administration. When comparing intraclass correlation coefficients (ICCs) at different points in the initial training, the Barnes Akathisia Scale and Anchored Brief Psychiatric Rating Scale reliability improved from 0.68 to 0.74 and from 0.54 to 0.87, respectively. After analyzing the ratings collected prior to the start of CS #394, data were collected to conduct the first check on Abnormal Involuntary Movement Scale (AIMS) IRR during enrollment; the estimated ICC for the AIMS had decreased from 0.87 to 0.60. Raters were instructed to re-assess the subjects from the first videotape on the AIMS and received additional training. The re-rating indicated very good reliability, 0.84, IRR was measured once for the Global Assessment of Functioning Scale resulting in an ICC of 0.90. The companion article (Part II: Edson et al. 1997, page 59 of this issue) describes the statistical procedures used to measure IRR.

Trazodone for antidepressant-associated insomnia

OBJECTIVE

The authors investigated trazodone as a hypnotic for depressed patients who had persistent, exacerbated, or new insomnia while taking either fluoxetine or bupropion.

METHOD

Seventeen depressed patients who had insomnia while taking fluoxetine or bupropion were given either trazodone or placebo in a double-blind crossover trial. Sleep was assessed by self-report with the Pittsburgh Sleep Quality Index and the sleep items of the Yale-New Haven Hospital Depressive Symptom Inventory.

RESULTS

Improvement with trazodone, but not with placebo, was shown by the total Pittsburgh index scores and Yale-New Haven inventory total sleep scores and by the Pittsburgh index measures of sleep duration and Yale-New Haven inventory measures of early morning awakening, and there was a trend toward improvement in the Yale-New Haven inventory item regarding middle of the night awakenings. Subjective sleep quality and sleep latency also showed a trend toward improvement, but the Pittsburgh index measures of sleep efficiency and disturbances and the Yale-New Haven inventory item regarding difficulty falling asleep were unaffected by trazodone. One patient dropped out because of excessive daytime sedation with trazodone, and another dropped out because of nonresponse to placebo. Of the completers, 67% experienced overall improvement in sleep with trazodone according to a priori criteria, whereas only 13% experienced improvement with placebo.

CONCLUSIONS

Trazodone is an effective hypnotic for patients with antidepressant-associated insomnia.

Vitamin E treatment of tardive dyskinesia

OBJECTIVE

The authors studied the effects of vitamin E treatment of tardive dyskinesia; earlier studies have produced contradictory results.

METHOD

Twenty-eight patients with tardive dyskinesia were treated in a double-blind, parallel-group comparison study of 8-12 weeks of treatment with vitamin E (1600 IU/day) or matching placebo capsules.

RESULTS

The Abnormal Involuntary Movement Scale scores of the patients treated with vitamin E improved significantly compared to the scores of the patients given placebo.

CONCLUSIONS

These results support earlier findings of the efficacy of vitamin E in treating tardive dyskinesia.

Stroke prevention by losartan in stroke-prone spontaneously hypertensive rats

BACKGROUND

Chronic angiotensin converting enzyme (ACE) inhibitor therapy with enalapril, captopril or ceranopril prevents the development of cerebrovascular lesions in stroke-prone spontaneously hypertensive rats (SHRSP) given a 1% NaCl solution to drink, with little or no effect on systolic blood pressure.

OBJECTIVES

To determine the effect of the orally active angiotensin (Ang) II receptor antagonist losartan on blood pressure and stroke in SHRSP.

METHODS

Losartan or vehicle was chronically administered to saline-drinking SHRSP, and systolic blood pressure was monitored. The effect of losartan on arterial blood pressure measured by radiotelemetry in enalapril-treated SHRSP was also examined.

RESULTS

Oral losartan at 30 mg/kg per day delayed the development of severe hypertension and prevented stroke in saline-drinking SHRSP. Losartan therapy at a dose of 10 mg/kg per day did not affect the systolic blood pressure elevation but prevented the occurrence of cerebrovascular lesions at least until 28 weeks of age. Radiotelemetric monitoring of arterial blood pressure in enalapril-treated, saline-drinking SHRSP over a 3-month period verified the maintenance of severe hypertension without any strokes. Treatment with oral losartan at a dose of 30 mg/kg did not affect the blood pressure of SHRSP chronically treated with enalapril.

CONCLUSIONS

These results are consistent with the theory that Ang II has an effect on the pathophysiology of cerebrovascular lesion development in saline-drinking SHRSP. These findings indicate that losartan has a protective action, similar to that previously observed with ACE inhibitors, against the development of cerebrovascular lesions in SHRSP in the absence of a blood pressure fall.

Vitamin E in tardive dyskinesia: time course of effect after placebo substitution

Alpha-tocopherol (vitamin E) has been found to be effective in the treatment of tardive dyskinesia (TD). Studies to date have been short in duration and have not found long-term carryover effects of vitamin E. The present study examined the persistence of the effects of vitamin E after longer term (36-week) treatment was discontinued. Vitamin E significantly improved TD over this period. However, the effects of vitamin E persisted so that TD scores approached baseline only after 12 weeks of placebo substitution.

Efficacy of betaxolol in neuroleptic-induced akathisia

Betaxolol, a beta 1-selective antagonist, produced marked improvement in eight patients with neuroleptic-induced akathisia. No further improvement was seen with subsequent propranolol treatment. These findings, along with the results of prior studies of betaxolol and metoprolol, suggest that blockade of central beta 1-receptors may be sufficient for efficacy in akathisia.

Lack of efficacy of d-propranolol in neuroleptic-induced akathisia

d-Propranolol lacks clinically significant beta-adrenergic receptor blocking properties, but has the same membrane stabilizing effects as racemic (d,l) propranolol. To assess the role of beta-blockade versus membrane stabilization or other shared nonspecific effects in the therapeutic action of propranolol in neuroleptic-induced akathisia (NIA) we treated 11 patients with NIA in a crossover, double-blind study of d-propranolol versus placebo. Akathisia scores were unchanged after both d-propranolol and placebo. Eight patients were subsequently treated in a nonblind manner with racemic propranolol, with a significant reduction in akathisia scores. These findings suggest that beta-blockade, not membrane stabilization or other shared nonspecific effects, contributes to the efficacy of propranolol in NIA.

Neuroleptic-induced akathisia: a review

Neuroleptic-induced akathisia (NIA) is a relatively common side effect of neuroleptics, in which patients complain of a subjective sense of restlessness usually referable to the legs and have characteristic motor movements. This paper will review: 1) history of spontaneously occurring syndromes of pathologic restlessness and NIA, 2) the clinical significance of NIA, 3) issues concerning the diagnosis and quantification of NIA, 4) treatments of NIA and 5) possible future directions for research in this area. Special attention will be paid to newer treatments for this syndrome, specifically beta-blockers.

Cloning and expression in Escherichia coli of genes encoding a multiprotein complex involved in secretion of proteins from Staphylococcus aureus

The genes encoding the multiprotein membrane-bound ribosomal protein (MBRP) complex (mrp genes), associated with membrane-bound ribosomes in Staphylococcus aureus, were cloned in Escherichia coli. All four components (molecular sizes 71, 60, 46, and 41 kilodaltons) of the MBRP complex were expressed from an 8.5-kilobase DNA fragment as judged by Western blot (immunoblot) analysis. The order of the individual genes within the cloned DNA fragment was determined by deletion mutagenesis and subcloning of various restriction fragments. Three RNAs, transcribed from the same DNA strand, were identified within the MBRP-coding region: one large RNA of approximately 5.9 kilobases, presumably coding for all four MBRP components, and two minor RNAs, coding for MBRP-71 and MBRP-60. The two minor RNAs seemed to be transcribed from promoters within the large transcription unit. Attempts to make insertional inactivations of the mrp genes with an internal 600-base-pair DNA fragment of the MBRP-coding region as a target were unsuccessful, presumably because such insertions are lethal.

Correlation between the rate of exoprotein synthesis and the amount of the multiprotein complex on membrane-bound ribosomes (MBRP-complex) in Staphylococcus aureus

The membrane-bound ribosome protein (MBRP)-complex of Staphylococcus aureus was studied using antibodies to its individual components. The four polypeptides of the complex were firmly held together, and none were present in large excess. The membrane-bound fraction of the MBRP-complex was accessible to trypsin only after removal of the membrane-bound ribosomes; it also remained associated with the membrane-bound ribosomes even after solubilization of the membranes with Triton X-100. Furthermore, the amount of MBRP-complex in the membrane was proportional to the rate of exoprotein synthesis. These results strongly suggest a role for the MBRP-complex in protein secretion.

Clonidine in neuroleptic-induced akathisia

Six hospitalized patients with neuroleptic-induced akathisia were treated with clonidine under single-blind conditions. Akathisia and anxiety at maximum clonidine dose were significantly lower than at baseline, although it was difficult to differentiate specific therapeutic effects from sedation.

Detection of a membrane-associated protein on detached membrane ribosomes in Staphylococcus aureus

Membrane ribosomes from Staphylococcus aureus which were detached from the membrane by extraction with the nonionic detergent Triton X-100 retained a protein (MBRP) with a molecular weight of 60 000, which was absent from cytoplasmic ribosomes. MBRP was detected and quantified by immunological methods. When membrane ribosomes were dissociated into 50S and 30S subunits, MBRP remained associated with the 50S particle. MBRP was found both on membrane ribosomes and in the cytoplasm in roughly equal amounts. When added to Triton X-100-solubilized protoplasts, antibodies to MBRP produced immunoprecipitates which contained a complex of MBRP and three other proteins with molecular weights of 71 000, 46 000 and 41 000. Four proteins with the same molecular weights as those of the MBRP complex were found associated with membrane ribosomes. The proteins of molecular weight 71 000, 60 000, 46 000 and 41 000 seemed to be present in stoichiometrically equivalent amounts in the complex.