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Chittaranjan Andrade

Publications and source records attributed to Chittaranjan Andrade.

At least 19 recordsLinked to original sources
PubMed2004

Antidepressant-withdrawal mania:a critical review and synthesis of the literature.

BACKGROUND: Hypomania or mania have rarely been reported to develop shortly after the discontinuation of an antidepressant drug. The true incidence of this discontinuation syndrome is unknown because it may be underreported as a consequence of underrecognition or misattribution. This article examines the possible etiology, nosology, mechanisms, and other aspects of the syndrome. DATA SOURCES AND STUDY SELECTION: A PubMed search was conducted in May 2003 and repeated in January 2004 using the search terms antidepressant and mania. Relevant articles containing adequate descriptions for presentation were retrieved, and their reference lists were hand-searched for further pertinent material. Hand-searches of the indexes of leading psychiatry journals were also performed for the years 1998-2003. Twenty-three articles were identified for review. CONCLUSIONS: Antidepressant-withdrawal hypomania or mania may occur rarely with almost any antidepressant drug after sudden withdrawal, tapered discontinuation, or even merely a decrease in dose. The syndrome may be self-limiting, may abate with the reinstitution of the antidepressant drug, or may require specific anti-manic treatments; mood stabilizers do not necessarily protect against the syndrome. The true incidence of the syndrome is unknown. Narrow and broad diagnostic criteria are proposed for the syndrome, and a synthesis of literature is provided.

Antidepressive Agents↗
PubMed2003

ECS seizure threshold: normal variations, and kindling effects of subconvulsive stimuli.

BACKGROUND: The efficacy and adverse effects of electroconvulsive therapy are generally believed to depend upon the extent to which an administered stimulus is suprathreshold. The seizure threshold is therefore an important biologic marker. We sought to examine the variability of the electroconvulsive shock (ECS) seizure threshold in rats, and to identify factors influencing the threshold, to guide future research using animal models. MATERIALS AND METHODS: We administered once-daily subconvulsive stimuli to Wistar rats beginning at a charge of either 1 mC (n = 25) or 5 mC (n = 25) and titrated the dose upward in 1-mC steps until the baseline seizure threshold was identified. Two weeks later, we divided each group into two subgroups and administered stimuli that were either at or 2 mC below the baseline threshold, and titrated the dose upward, again in 1-mC steps once daily, until the final threshold was identified. RESULTS: The mean baseline seizure threshold was 3.8 mC when upward titration was begun at 1 mC, and 6.7 mC when upward titration was begun at 5 mC (p < 0.001). Two weeks later, titration from baseline-subthreshold stimuli was associated with a lower final threshold in the 5-mC group, while titration from baseline-threshold stimuli was associated with a higher final threshold in the 1-mC group (p < 0.006). CONCLUSIONS: The ECS seizure threshold ranged from 3 to 7 mC in this sample of rats; since the twofold variation is very small relative to clinical contexts, it is unlikely that ECS research needs to be threshold-based. The administration of low-dose, once-daily subconvulsive stimuli significantly lowered the seizure threshold; while this kindling effect wore off within 2 weeks, thresholds otherwise identified remained stable at the 2-week time point.

Animals↗
PubMed2003

Confirmation of whole-brain kindling with repeated subthreshold electroconvulsive shocks: a controlled study.

BACKGROUND: Repeated, subconvulsive electroconvulsive shock (ECS) stimuli, administered a day apart, lower the ECS seizure threshold in rats. It is not known, however, whether this kindling results from the repeated subconvulsive stimulation or from the stress induced by the experimental procedures. MATERIALS AND METHODS: Adult, male Wistar rats were randomized to receive a 3-mC ECS stimulus (n = 20), a 30-V (0.3-s) footpad shock (n = 20), or sham ECS and sham footpad shock (n = 20). All procedures were conducted once daily for 3 consecutive days. On the fourth day, all rats received a 3-mC ECS stimulus. RESULTS: At the end of the experiment, 85% of the rats in the ECS group but only 35% of the rats in each of the other two groups had experienced a seizure with the 3-mC stimulus (p < 0.001). CONCLUSION: The lowering of the ECS seizure threshold by repeated, once-daily subconvulsive stimuli is caused by the subconvulsive stimulation itself, not by experimental stress.

Animals↗
PubMed2003

Spectral EEG effects of electroconvulsive shock stimulus parameters: the development of a rationale for the optimization of the ECT stimulus.

BACKGROUND: Electroconvulsive therapy (ECT) stimulus parameters, such as pulse amplitude, pulse width, pulse frequency, and stimulus duration, differently influence seizure threshold and, possibly, other neurobiological effects of ECT. We examined the influence of these parameters on the EEG power spectrum in an animal model. METHODS: Adult, male, Wistar rats (n=54) were randomized to receive one of five differently constituted (approximately) 30-mC electroconvulsive shock (ECS) stimuli administered once on alternate days for a total of three ECS. A single-lead, unipolar EEG recording was obtained before, during, and immediately after each ECS seizure. EEG power was computed in eight frequency bands from 2 to 40 Hz. Greater ictal EEG power, greater postictal EEG suppression, and greater interictal EEG power, especially in lower frequency bands, were a priori defined as proxies of seizure efficacy. RESULTS: Motor and EEG seizure duration and a proxy for seizure generalization did not differ significantly across the five stimulus groups. Despite equivalent charge, the five stimuli varied widely in their effects on the EEG proxies of seizure efficacy. The narrow (0.6 milliseconds) pulse width, high (100 Hz) pulse frequency combination was best associated with EEG proxies of seizure efficacy; with this combination, a longer stimulus train duration appeared superior to a greater pulse amplitude. The wide (2 milliseconds) pulse and low (30 Hz) frequency combination was least associated with EEG proxies of efficacy. Stimulus "on" time, number of pulses delivered, and the rate of delivery of charge were not associated with the EEG proxies; the former finding questions the validity of dosing ECT in units of charge. CONCLUSIONS: These findings suggest a rationale for optimizing stimulus parameter choices during ECT and provide a framework for the evaluation of electrical aspects of the ECT stimulus.

Animals↗
PubMed2003

Pharmacological treatment of severe psychiatric disorders in the developing world : lessons from India.

Severe psychiatric disorders (schizophrenia, bipolar disorder and major depressive disorder) cause much morbidity and disability in developing countries. Most of the evidence on the efficacy and effectiveness of drug treatments for these disorders is based on trials conducted in Western countries. Cultural, biological and health system factors may profoundly influence the applicability of such evidence in developing countries. Attitudes towards, and concepts about, psychiatric disorders vary across cultures, and these may influence the acceptability of drug treatments. Genetic and environmental factors may lead to variations in the pharmacodynamics and pharmacokinetics of psychotropic drugs across ethnic groups. This may explain why lower doses of psychotropic drugs tend to be used for non-Caucasian patients. There is a dearth of mental health professionals and care facilities in developing countries, especially in rural areas. Epidemiological studies show that, despite this lack of services, the outcome of schizophrenia is favourable in developing countries. This suggests that cultural, genetic or environmental factors may play as much of a role in influencing outcome as access to antipsychotic treatment. Regional drug policies may influence the availability and cost of psychotropic drugs. In particular, the Indian experience, where drugs are manufactured by several local pharmaceutical firms, thus bringing their cost down, may represent a unique deregulated drug industry. However, the impending impact of the Trade-Related Aspects of Intellectual Property Rights (TRIPS) agreement, with the strict enforcement of patent laws, will almost certainly lead to a rise in drug costs in the coming years. This may influence the choice and cost effectiveness of various drugs. The implications of these cross-cultural variations for policy and practice are the need to ensure a reliable supply of affordable psychotropic drugs in developing countries, trained healthcare professionals to use these drugs rationally, a concerted advocacy campaign to exclude drugs for severe psychiatric disorders from patent protection, and the development of psychosocial programmes to improve global outcomes.

Central Nervous System Agents↗