Papers by Rajiv Radhakrishnan
The Journal of Clinical Psychiatry, 2016
The Lancet Psychiatry, 2016
The American journal of psychiatry, 2016
The American journal of psychiatry, 2015
Annual Review of Medicine, 2014
Marijuana is becoming legal in an increasing number of states for both medical and recreational u... more Marijuana is becoming legal in an increasing number of states for both medical and recreational use. Considerable controversy exists regarding the public health impact of these changes. The evidence for the legitimate medical use of marijuana or cannabinoids is limited to a few indications, notably HIV/AIDS cachexia, nausea/vomiting related to chemotherapy, neuropathic pain, and spasticity in multiple sclerosis. Although cannabinoids show therapeutic promise in other areas, robust clinical evidence is still lacking. The relationship between legalization and prevalence is still unknown. Although states where marijuana use is legal have higher rates of use than nonlegal states, these higher rates were generally found even prior to legalization. As states continue to proceed with legalization for both medical and recreational use, certain public health issues have become increasingly relevant, including the effects of acute marijuana intoxication on driving abilities, unintentional ingestion of marijuana products by children, the relationship between marijuana and opioid use, and whether there will be an increase in health problems related to marijuana use, such as dependence/addiction, psychosis, and pulmonary disorders. In light of this rapidly shifting legal landscape, more research is urgently needed to better understand the impact of legalization on public health. Expected final online publication date for the Annual Review of Medicine Volume 67 is January 14, 2016. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.
Indian journal of physiology and pharmacology
Depression has been linked to altered cardiac autonomic regulation. Previous studies have been in... more Depression has been linked to altered cardiac autonomic regulation. Previous studies have been inconsistent in terms of measurement of heart rate variability (HRV), selection of depressed patients with cardiac disorders and not controlling for co-morbid conditions such as substance use and anxiety disorders. The objective of this study is to compare the effect of posture on spectral measures of HRV in drug naive healthy patients with major depression with age and gender matched healthy controls. Spectral measures of HRV in supine position and with active standing were obtained (using Task force recommendations). Repeated measure ANOVA revealed an attenuated response in HRV parameters (HF normalized units & LH/HF ratio) to active standing in depressed subjects compared to healthy controls. We conclude that there is an impaired parasympathetic modulation in response to physiological maneuver (orthostatic challenge) in drug naive subjects with major depression (co-morbid medical or psy...
The Journal of Clinical Psychiatry, 2014
Psychiatric hospital readmissions correlate with illness severity, drug selection, and compliance... more Psychiatric hospital readmissions correlate with illness severity, drug selection, and compliance with treatment in the outpatient setting. The risk factors for psychiatric rehospitalization have been mainly assessed in databases lacking information regarding somatic comorbidity and anthropometric variables, such as body mass index (BMI), which are known to predict readmissions in nonpsychiatric settings. To determine independent predictors of 1-year readmission occurring among unselected adults consecutively admitted for treatment of severe mental illness to an academic, freestanding psychiatric hospital in New York City from August 2010 through January 2011. After identifying univariate correlates of readmission, we used logistic regression with backward elimination to identify independent predictors of readmissions within 1 year after the index psychiatric hospitalization. Among 224 (23.7%) of 945 readmitted patients, psychiatric readmission was significantly associated with age (P = .0029), length of stay (P = .036), schizophrenia/schizoaffective disorder (P < . 0001), dementia (P = .027), major depressive disorder (P = .0006), treatment with atypical antipsychotic drugs (P = .0054), electroconvulsive therapy (P < .0001), and BMI (P = .0079), but not with physical comorbidities and routine laboratory data.The independent predictors of readmission were higher BMI (median = 28.5 kg/ m2; odds ratio [OR] = 3.6; Cl, 1.2-10.6), a diagnosis of schizophrenia/schizoaffective disorder (OR = 2.2; Cl, 1.5-3.4), clozapine treatment (OR = 2.8; CI, 1.1-6.9), no electroconvulsive therapy (OR = 0.13; Cl, 0.02-0.45), and shorter length of stay (median = 18 days; OR = 0.08; Cl, 0.01-0.42). Body mass index was identified, for the first time, as an independent predictor of psychiatric rehospitalization. Enhanced outpatient treatment programs for overweight and obese psychiatric patients might influence readmission rates and should be explored in prospective studies.
Neurosurgery, 2012
Knowledge of the properties of white matter fiber tracts isa crucial and necessary step toward a ... more Knowledge of the properties of white matter fiber tracts isa crucial and necessary step toward a precise understanding of the functional architecture of the living human brain. Previously, this knowledge was severely limited, as it was difficult to visualize these structures or measure their functions in vivo. The HCP has recently generated considerable interest because of its potential to explore connectivity and its relationship with genetics and behavior. For neuroscientists and the lay public alike, the ability to assess, measure, and explore this wealth of layered information concerning how the brain is wired is a much sought after prize.The navigation of the human connectome and the discovery of how it is affected through genetics, and in a range of neurological and psychiatric diseases, have far reaching implications. From a range of ongoing connectomics related activities, the systematic characterization of brain connectedness and the resulting functional aspects of such connectivity will not only realize the work of Ramón y Cajal and others, but will also greatly expand our understanding of the brain, the mind, and what it is to be truly human. The similarities and differences that mark normal diversity will help us to understand variation among people and set the stage to chart genetic influences on typical brain development and decline during aging. What is more, an understanding of how brains might become disordered will shed light on autism, schizophrenia, Alzheimer’s, and other diseases that exact a tremendous and terrible social and economic toll.
The Primary Care Companion to the Journal of Clinical Psychiatry, 2013
Indian Journal of Psychiatry, 2009
Antipsychotic drugs are commonly used in the treatment of the behavioral and psychological sympto... more Antipsychotic drugs are commonly used in the treatment of the behavioral and psychological symptoms of dementia (BPSD). We present a qualitative review of the data on the efficacy and safety of antipsychotic drugs for BPSD. We more specifically examine safety issues with an especial focus on recent research. We examine two safety studies in detail to provide readers with a critical perspective. Typical and atypical antipsychotic drugs both attenuate the severity of BPSD; however, both categories of drugs increase the risk of cerebrovascular and other adverse events, as well as the risk of death. The risk appears greater with the typical drugs, with higher doses, and during the initial weeks of treatment. The risk probably persists for as long as a year after the initiation of treatment. Both drug- and patient-related factors appear to mediate this increase in risk. Antipsychotic drugs should be considered for BPSD only if there is a specific need, or if other treatments have failed; decision-making should be individualized and documented after a risk-benefit analysis. Atypical antipsychotics appear safer than the typical drugs. The lowest effective dose should be used.
The Journal of Ect, Oct 1, 2009
Biological psychiatry, 2016
Some of the most compelling evidence supporting an association between cannabinoid agonists and p... more Some of the most compelling evidence supporting an association between cannabinoid agonists and psychosis comes from controlled laboratory studies in humans. Randomized, double-blind, placebo-controlled, crossover laboratory studies demonstrate that cannabinoid agonists, including phytocannabinoids and synthetic cannabinoids, produce a wide range of positive, negative, and cognitive symptoms and psychophysiologic deficits in healthy human subjects that resemble the phenomenology of schizophrenia. These effects are time locked to drug administration, are dose related, and are transient and rarely necessitate intervention. The magnitude of effects is similar to the effects of ketamine but qualitatively distinct from other psychotomimetic drugs, including ketamine, amphetamine, and salvinorin A. Cannabinoid agonists have also been shown to transiently exacerbate symptoms in individuals with schizophrenia in laboratory studies. Patients with schizophrenia are more vulnerable than health...
Asian Journal of Psychiatry, 2015
Asian Indians represent a significant portion of the largest growing race of Asians in the past d... more Asian Indians represent a significant portion of the largest growing race of Asians in the past decade in the United States. This selective review examines major cultural themes related to first- and second-generation Asian Indians living in the United States as they impact psychological and psychiatric dysfunction in this population. Specifically, we review the impact of Asian Indian culture on mental health, discuss the impact of acculturation and ethnic identity development on the mental health of Indian-Americans, and focus on typical mental health problems of Asian Indian adolescents, women and elderly in America. Finally, we provide a brief overview of empirically-supported treatment approaches and cultural considerations for additional treatments relevant to this population. This review is intended to provide an important foundation for more systematic empirically-driven investigation into better understanding how Asian Indian cultural themes impact mental health for Indian-Americans, and how to develop effective treatments for these issues in this cultural group.
Biological Psychiatry, 2015
Several lines of evidence suggest the presence of abnormalities in the endocannabinoid (eCB) syst... more Several lines of evidence suggest the presence of abnormalities in the endocannabinoid (eCB) system in schizophrenia (SCZ). However, there are limited in vivo measures of the eCB system in SCZ. Twenty five male SCZ subjects (SCZs) (18 antipsychotic treated and 7 antipsychotic free) were compared with 18 age-matched male healthy control subjects (HCs). Subjects underwent one positron emission tomography scan each with the cannabinoid receptor-1 (CB1R) selective radiotracer [(11)C]OMAR on the high resolution research tomography scanner. Regional volume of distribution (VT) values were determined using kinetic modeling of positron emission tomography data as a measure of CB1R availability. Group differences in mean composite [(11)C]OMAR VT values were compared between SCZs and HCs. Exploratory comparisons of CB1R availability within 15 brain regions were also conducted. All analyses were covaried for age and body mass index. SCZs showed significantly (p = .02) lower composite [(11)C]OMAR VT relative to HCs (~12% difference, effect size d = .73). [(11)C]OMAR VT was significantly (all ps < .05) lower in SCZs in the amygdala, caudate, posterior cingulate cortex, hippocampus, hypothalamus, and insula. Composite [11]OMAR VT was HCs > antipsychotic treated SZCs > antipsychotic free SZCs. Furthermore, composite [(11)C]OMAR VT was greater in HCs than SCZ smokers (n = 11) and SCZ nonsmokers (n = 14). CB1R availability is lower in male SCZ subjects compared with HCs. Furthermore, antipsychotics and tobacco use may increase CB1R availability in this population. The findings of the study provide further evidence supporting the hypothesis that alterations in the eCB system might contribute to the pathophysiology of SCZ.
The Psychiatric quarterly, Jan 8, 2015
Cognitive remediation (CR) has been found to improve cognitive performance among adults with schi... more Cognitive remediation (CR) has been found to improve cognitive performance among adults with schizophrenia in randomized controlled trials (RCTs). However, improvements in cognitive performance are often observed in the control groups of RCTs as well. There has been no comprehensive examination of change in control groups for CR, which may inform trial methodology and improve our understanding of measured outcomes for cognitive remediation. In this meta-analysis, we calculated pre-post change in cognitive test performance within control groups of RCTs in 32 CR trials (n = 794 participants) published between 1970 and 2011, and examined the association between pre-post change and sample size, duration of treatment, type of control group, and participants' age, intelligence, duration of illness, and psychiatric symptoms. Results showed that control groups in CR trials showed small effect size changes (Cohen's d = 0.12 ± 0.16) in cognitive test performance over the trial duratio...
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Papers by Rajiv Radhakrishnan