Biomedical subjects

Anil Malhotra

Publications and source records attributed to Anil Malhotra.

4 recordsLinked to original sources

PubMed2006

Emotion-based decision-making in healthy subjects: short-term effects of reducing dopamine levels.

INTRODUCTION: Converging evidences from animal and human studies suggest that addiction is associated with dopaminergic dysfunction in brain reward circuits. So far, it is unclear what aspects of addictive behaviors are related to a dopaminergic dysfunction. DISCUSSION: We hypothesize that a decrease in dopaminergic activity impairs emotion-based decision-making. To demonstrate this hypothesis, we investigated the effects of a decrease in dopaminergic activity on the performance of an emotion-based decision-making task, the Iowa gambling task (IGT), in 11 healthy human subjects. MATERIALS AND METHODS: We used a double-blind, placebo-controlled, within-subject design to examine the effect of a mixture containing the branched-chain amino acids (BCAA) valine, isoleucine and leucine on prolactin, IGT performance, perceptual competency and visual aspects of visuospatial working memory, visual attention and working memory, and verbal memory. The expectancy-valence model was used to determine the relative contributions of distinct IGT components (attention to past outcomes, relative weight of wins and losses, and choice strategies) in the decision-making process. OBSERVATIONS AND RESULTS: Compared to placebo, the BCAA mixture increased prolactin levels and impaired IGT performance. BCAA administration interfered with a particular component process of decision-making related to attention to more recent events as compared to more distant events. There were no differences between placebo and BCAA conditions for other aspects of cognition. Our results suggest a direct link between a reduced dopaminergic activity and poor emotion-based decision-making characterized by shortsightedness, and thus difficulties resisting short-term reward, despite long-term negative consequences. These findings have implications for behavioral and pharmacological interventions targeting impaired emotion-based decision-making in addictive disorders.

Amino Acids, Branched-Chain↗

PubMed2006

Comparative study of neuropsychological correlates in schizophrenia with onset in childhood, adolescence and adulthood.

Childhood onset schizophrenia (COS) patients have marked neuropsychological deficits in areas of attention, working memory and executive functions. Similar deficits have been found in studies on Adolescent onset (AdOS) and Adult onset schizophrenia (AOS). In this study we compared the neuropsychological profile of COS with AdOS and AOS to test the hypothesis that earlier the onset greater is the severity of illness and greater are the neuropsychological deficits. A sample of 15 patients of COS was compared with 20 patients each of AdOS and AOS group. Assessment of neuropsychological profile was done using standard neuropsychological battery for Indian population. Nahor Benson Test and Bender Visual Motor Gestalt Test were used to assess perceptuomotor functioning. COS patients showed significantly greater deficits on scales of IQ, memory and perceptuomotor skills as compared to AdOS that in turn had greater deficits than AOS. The persistence of differences across the three groups inspite of controlling for education and age suggest that these deficits may have been present even before the onset of illness and was not the result of poor academic achievements. These findings also point towards a brain damage in schizophrenia that occurs on a continuum of severity with COS being the most virulent, AOS being the least and AdOS falling in between these two extremes.

Adolescent↗

PubMed2003

The future of pharmacotherapy for schizophrenia.

Although enormous progress has been made in the treatment of schizophrenia, and the use of existing pharmacologic agents can have a dramatic effect on the short- and long-term management of the disorder, enormous challenges and unmet needs continue to exist. Despite the introduction of a second generation of antipsychotic medications, many patients continue to derive inadequate benefits from available agents. Negative symptoms and cognitive dysfunction, and decrements in psychosocial and vocational functioning, often continue to persist despite our best available treatments. Medication adherence remains a constant challenge and has not been dramatically improved by the new-generation antipsychotic drugs. Since all currently marketed antipsychotic agents possess some degree of dopamine antagonist effects, the role of other neurotransmitters in the primary antipsychotic activity remains largely unclear. It is possible that different domains of disease effects might benefit from different specific classes of medications, yet research in this area is not highly developed. The promise of further discoveries in genetics leading to new treatment targets and better predictors of treatment response (both therapeutic and adverse) is enormously exciting, but these developments will require years of additional research. The field must balance the need to make the most informed and thorough use of available agents with a sense of both excitement and patience as we work toward other approaches.

Journal Article↗

PubMed1984

Non-organic chronic intractable pain: a comparative study.

This report compares patients with non-organic chronic intractable (NOCI) pain with those having chronic pain associated with diagnosed physical illness though it was insufficient to explain the severity and nature of pain. Samples were selected after strict screening procedures. The results reveal that NOCI pain is more often seen in those who are younger, unmarried, with higher education and belonging to a professional group of occupation. Chronic pain associated with physical illness is reported more by elderly, married, those with lesser education and housewives. However, only slight differences were noticeable in the clinical characteristics of pain. Thus there are two distinct groups of chronic pain patients. These differences, along with less predominance of low back pain and high number of whole body pain in the samples suggest cultural differences in localisation and presentation of chronic pain.

Adolescent↗