scholarly journals Ketamine and neuroticism: a double-hit hypothesis of internalizing disorders

2020 ◽  
Vol 3 ◽  
Author(s):  
N. McNaughton ◽  
P. Glue
Keyword(s):  
Low Dose ◽  
Internalizing Disorders ◽  
Neural System ◽  
The Other ◽  
Hyperactivity Disorder ◽  
Speed Of Response ◽  
Symptom Ratings ◽  
Double Hit ◽  
Primary Action ◽  
Neural Dysfunction

Abstract Psychiatric disorders can often be viewed as extremes of personality traits. The primary action of drugs that ameliorate these disorders may, thus, be to alter the patient’s position on a relevant trait dimension. Here, we suggest that interactions between such trait dimensions may also be important for disorder. Internalizing disorders show important differences in terms of range of activity and speed of response of medications. Established antidepressant and anxiolytic medications are slow in onset and have differing effects across different internalizing disorders. In contrast, low-dose ketamine is rapidly effective and improves symptom ratings in all internalizing disorders. To account for this, we propose a “double hit” model for internalizing disorders: generation (and maintenance) require two distinct forms of neural dysfunction to coincide. One hit, sensitive to ketamine, is disorder-general: dysfunction of a neural system linked to high levels of the personality trait of neuroticism. The other hit is disorder-specific: dysfunction of one of a set of disorder-specific neural modules, each with its own particular pattern of sensitivity to conventional drugs. Our hypothesis applies only to internalizing disorders. So, we predict that ketamine will be effective in simple phobia and (perhaps partially) in anorexia nervosa, but would make no such prediction about other disorders where neuroticism might also be important secondarily (e.g. attention deficit hyperactivity disorder and schizophrenia).

Dynamical behavior of simplified FitzHugh–Nagumo neural system with time delay driven by Lévy noise

2021 ◽  
pp. 2150240
Author(s):  
Weida Qiu ◽  
Yongfeng Guo ◽  
Xiuxian Yu
Keyword(s):  
Time Delay ◽  
First Passage Time ◽  
Dynamical Behavior ◽  
Passage Time ◽  
Neural System ◽  
The Other ◽  
Lévy Noise ◽  
First Passage ◽  
Levy Noise ◽  
System With Time Delay

In this paper, the dynamical behavior of the FitzHugh–Nagumo (FHN) neural system with time delay driven by Lévy noise is studied from two aspects: the mean first-passage time (MFPT) and the probability density function (PDF) of the first-passage time (FPT). Using the Janicki–Weron algorithm to generate the Lévy noise, and through the order-4 Runge–Kutta algorithm to simulate the FHN system response, the time that the system needs from one stable state to the other one is tracked in the process. Using the MATLAB software to simulate the process above 20,000 times and recording the PFTs, the PDF of the FPT and the MFPT is obtained. Finally, the effects of the Lévy noise and time-delay on the FPT are discussed. It is found that the increase of both time-delay feedback intensity and Lévy noise intensity can promote the transition of the particle from the resting state to the excited state. However, the two parameters produce the opposite effects in the other direction.

Low-dose heparin prophylaxis of postoperative venous thrombosis: preparations and costs

1972 ◽  
Vol 10 (25) ◽  
pp. 100-100
Keyword(s):  
Venous Thrombosis ◽  
Low Dose ◽  
The Other ◽  
Actual Cost ◽  
Correct Figure ◽  
Dose Heparin ◽  
Perioperative Course ◽  
Low Dose Heparin ◽  
Heparin Prophylaxis

Our article (November 10, p. 89) gave the basic NHS cost of a 7-day perioperative course (5000 i.u. 12-hourly) as 75 to 90p. MIMS gave the wrong price and in fact Weddel’s heparin costs the same as the other brands, and 75p. is the correct figure. It is worth noting that in the case of heparin, which is almost entirely used in hospitals, the actual cost is up to 25% less than the ‘basic NHS cost’, because most hospitals buy large quantities at special contract prices. The opposite is true for drugs dispensed by retail pharmacists, where the actual cost exceeds the basic NHS cost because it includes a dispensing fee and container allowance.

Research on the Educational Implications of Attention Deficit Hyperactivity Disorder

1993 ◽  
Vol 60 (2) ◽  
pp. 143-153 ◽  
Author(s):  
Sydney S. Zentall
Keyword(s):  
Academic Achievement ◽  
Attention Deficit Hyperactivity Disorder ◽  
Attention Deficit ◽  
The Other ◽  
Cognitive Disability ◽  
Academic Problems ◽  
Hyperactivity Disorder ◽  
Educational Implications ◽  
Students With Adhd

This article summarizes the major academic problems of students with attention deficit hyperactivity disorder (ADHD) and addresses the extent to which these problems are secondary to ADHD, rather than a part of a co-occurring learning or cognitive disability. The article delineates the academic problems of students with ADHD in relation to their primary characteristics—how one influences the nature of the other. Treatment implications are discussed to indicate how educators might modify classroom settings to enhance the academic achievement of students with ADHD.

Other Health Impairment (OHI) Disabilities Category and an In-Depth Look at the Most Common Neurobiological Condition for Students

2022 ◽  
pp. 55-68
Author(s):  
Tammy Reutzel Guthrie
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Kidney Disease ◽  
General Education ◽  
Sickle Cell Anemia ◽  
Health Problem ◽  
Educational Environment ◽  
The Other ◽  
Health Impairment ◽  
Hyperactivity Disorder ◽  
Other Health Impairment

The other health impairment (OHI) disability category refers to a condition that causes limited strength, vitality, or alertness, including heightened alertness to environmental stimuli that results in limited alertness with respect to the educational environment due to a chronic or acute health problem and adversely affects a child's educational performance. This disability category, as explored in this chapter, may include one or a combined type of attention-deficit hyperactivity disorder, asthma, diabetes, epilepsy, a heart condition, kidney disease, sickle cell anemia, and Tourette's syndrome. As a result of the child's other health impairment, as described above, the child is prevented from receiving reasonable educational benefit from general education.

scholarly journals A-31 Trails-X Trail-Level Performance Using the Profile Variability Index

2019 ◽  
Vol 34 (6) ◽  
pp. 890-890
Author(s):  
J Greene ◽  
M Messer ◽  
D Hartman ◽  
C Reynolds
Keyword(s):  
The Other ◽  
Hyperactivity Disorder ◽  
Standardization Sample ◽  
Significant Difference ◽  
Trail Making ◽  
New Type ◽  
Variability Index ◽  
The Mean ◽  
Low Performance ◽  
Level Performance

Abstract Objective The Trails-X is a new type of trail-making test that emphasizes executive function and does not require either literacy or numeracy. The purpose of this study was to examine performance variability across trails. Method Participants were the Trails-X standardization sample and individuals with traumatic brain injury (TBI), learning disabilities (LD), intellectual disabilities (ID), attention-deficit hyperactivity disorder (ADHD), and dementia. Trail-level performance was assessed via the mean Matrix, Connected Circles, and Time to Discontinue scores across trails. The Profile Variability Index (PVI) was calculated (Plake, Reynolds, & Gutkin, 1981) and clinical groups and standardization samples were compared via a one-way ANOVA. Results Across all trails, the mean Matrix score was 6 (possible range = 1-12) for the standardization sample and as low as 3 for the dementia and ID samples. The mean Connected Circles score was 16 (possible range = 0-22) and as low as 12 for the dementia sample. The mean Time to Discontinue score was 39 seconds (possible range = 1-75) and as high as 55 for the dementia sample. There was a statistically significant difference on the PVI score (F(5,845) = 6.921, p = .000). The dementia (M = 4.77) and ID (M = 5.11) samples had significantly lower (p < .05) PVI scores than the other samples, which were not significantly different from each other. Conclusions The dementia and ID samples were characterized by consistently low performance while the other samples were characterized by moderate amounts of variability, indicating that some variability across trails should be expected within less impaired individuals.

scholarly journals Sex and Informant Effects on Diagnostic Comorbidity in an Adolescent Community Sample

2005 ◽  
Vol 50 (8) ◽  
pp. 479-489 ◽  
Author(s):  
Elisa Romano ◽  
Richard E Tremblay ◽  
Frank Vitaro ◽  
Mark Zoccolillo ◽  
Linda Pagani
Keyword(s):  
Adolescent Girls ◽  
Depressive Disorders ◽  
Community Sample ◽  
Internalizing Disorders ◽  
Externalizing Disorders ◽  
Diagnostic Interview ◽  
Adolescent Boys ◽  
Hyperactivity Disorder ◽  
Informant Effects ◽  
Oppositional Disorder

Objective: To investigate sex and informant effects on comorbidity rates for anxiety disorders, depressive disorders, attention-deficit hyperactivity disorder (ADHD), and conduct–oppositional disorder (CD–ODD) in an adolescent community sample. Method: The Diagnostic Interview Schedule for Children-2.25 (DISC-2.25) was administered to 1201 adolescents and their mothers. Results: The highest comorbidity risk found was between ADHD and CD–ODD, with odds ratios (ORs) of 17.6 for adolescent reports and 12.0 for mother reports. The second-highest comorbidity risk, with ORs of 13.2 for adolescent reports and 11.0 for mother reports, was between anxiety and depressive disorders. There was not much overlap between internalizing and externalizing disorders. Adolescent girls had higher rates of coexisting anxiety and depressive disorders, whereas adolescent boys had higher rates of coexisting ADHD and CD–ODD. There was partial support for the hypothesis that adolescent-reported comorbidity rates would exceed mother-reported rates. Conclusions: There is a greater cooccurrence of within-category, compared with between-category, disorders. Adolescent girls are more likely to have coexisting internalizing disorders, while adolescent boys are more likely to have coexisting externalizing disorders. Mothers tend to report more externalizing disorders (that is, ADHD), while adolescents generally report more internalizing disorders.

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