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Biomedical subjects

N Dantchev

Publications and source records attributed to N Dantchev.

12 recordsLinked to original sources
PubMed1998

The measurement of retardation in depression.

The description of clinical features helps to distinguish between depressive illness and nondepressive psychic pain and enables the clinician to decide whether prescription of an antidepressant is beneficial. Psychomotor retardation is probably a central feature of depression, and this review discusses the methods available for measuring it. The Salpêtrière Retardation Rating Scale (SRRS) specifically measures psychomotor retardation; the scale and applications are described. Means of measuring motor and speech activity and an experimental approach for understanding the process underlying psychomotor retardation are reviewed. Comparison of the SRRS and other rating scale scores demonstrates that retardation is related to depression severity and therapeutic change and is a good criterion for prediction of therapeutic effect. The SRRS has been used to show that selective antidepressants target specific clinical dimensions of depression depending on the patient subgroup treated. Measures of motor and speech activity are sensitive to therapeutic response. Choice Reaction Time and Simple Reaction Time tasks are particularly suited for examining psychomotor retardation because they test the decision process while avoiding motivation and attention interference. Psychomotor retardation is a constant and probably central feature of depression. Means available for measuring it can be used to assess the effects of antidepressants on specific clinical dimensions.

Adrenergic Uptake Inhibitors↗
PubMed1994

Circadian pattern of motor activity in major depressed patients undergoing antidepressant therapy: relationship between actigraphic measures and clinical course.

The 24-hour motor activity pattern was evaluated in 26 inpatients with major depression at treatment onset and after 4 weeks of antidepressant therapy. Clinical state, depression, and psychomotor retardation, as well as motor activity level and circadian rhythm, were simultaneously assessed. Treatment responders and nonresponders were also considered. Diurnal hypoactivity and reduced 24-hour rhythm amplitude were found at treatment onset. Activity level increased significantly on discharge. The rest-activity cycle for each depressed patient fit a cosine function of 24-hour periodicity. Data tended to show no phase shift but a large intragroup phase variability. Preliminary findings of a negative correlation between basic activity level and clinical improvement, and a trend toward responders having a lower activity level than nonresponders, suggest that activity could be used to predict therapeutic response.

Adult↗
PubMed1992

Long-term treatment with different calcium- and calmodulin-antagonists induces changes in rat brain alpha-adrenoceptors.

1. The binding characteristics (Bmax and Kd) of the alpha-adrenoceptor radioligand [3H] WB4101 in crude membrane fraction (fraction P2) from cerebral cortex were studied after 13-day oral treatment of male Wistar rats with the Ca(2+)-antagonists nifedipine (20 mg/kg), verapamil (50 mg/kg), flunarizine (10 mg/kg) and with the calmodulin-antagonist trifluoperazine (TFP) (3 mg/kg). 2. A significant reduction of the binding sites (Bmax) for [3H] WB4101 was established after the three Ca(2+)-antagonists as well as after TFP treatment. 3. Different changes in the affinity constant (Kd) of brain adrenoceptors were observed depending on the type of the Ca2+ or CaM-antagonist used: nifedipine did not change the Kd value, verapamil and TFP decreased whereas flunarizine increased the Kd value. 4. Relationships between Ca ions and alpha-adrenoceptor functions are suggested.

Administration, Oral↗
PubMedDate not supplied

[Weight gain and antipsychotic drug treatment].

Like the classical neuroleptic drugs, most of the new antipsychotic agents can cause weight gain in patients receiving long-term treatment. However, it remains difficult to rank the different compounds according to their propensity to cause this unwanted side-effect. Recent data suggest that weight gain appears to be essentially related to an increase in appetite in these patients. Thus, it is a fact that the patients' diet represents the main predictive factor for weight gain, independently of the antipsychotic compound prescribed. In contrast to the other and often more disabling side-effects of these treatments, overweight can be effectively prevented by simple hygienic and dietetic measures. It would therefore be advisable to discuss the possibility of this side-effect of antipsychotic treatment with the patient, and to suggest appropriate preventive measures, as part of the therapeutic partnership.

Antipsychotic Agents↗
PubMedDate not supplied

[Significance of studies of motor activity in depression].

Actometry is a technique that enables continuous monitoring of spontaneous motor activity. This technique can be applied to the study of depression either by studying qualitative motor activity patterns or by measuring quantitative motor parameters. We present here the results of a quantitative actometric analysis. 13 depressive in-patients were evaluated both clinically by depression scales and by actometry before and after trimipramine treatment. Correlation analysis was made between actometric and clinical rating scores at different moments of the treatment. Some actometric parameters appear to be specific indices of depression and psychomotor retardation. Future prospects for the use of actometric techniques in depression are discussed.

Arousal↗
PubMedDate not supplied

[Charcot and hysteria].

Charcot's work on hysteria has always been controversial. All his attitudes, whether on the theory of the ovary, the hysteroepileptic seizure or the use of hypnosis, have always been charicatured, misunderstood and separated from the wider context of his overall approach. Rereading Charcot's works shows that he developed his approach progressively over a period of more than 20 years before coming to his psychological model of hysteria. This model explains the formation of the symptom and the hysterical conversion via a mechanism of being ignorant of the motor representation. This concept has never been disproven and remains the only theory explaining the formation of the hysteria symptom. Based on Charcot's fundamental contribution, Freud and Janet further developed their work on the psychopathology of hysteria.

History, 19th Century↗
PubMedDate not supplied

[Decision trees in psychiatric therapy].

The main objective of decision analysis is to offer a theoretical representation of choices made in an environment of uncertainty. This technique is currently under development in a great variety of fields, particularly in medicine, where aid in decision making is the topic of much research. Psychiatry, in turn, is very much concerned by these new developments which could be of particular interest to therapeutics-an area where the large number of studies and date are in great contrast with the lack of consensus concerning the various solutions proposed to patients. Decision analysis utilizes different techniques among which are decision trees. The technique of decision trees goes far beyond a simple graphic representation of reasoning in the form of a chart. Its basic principles is to measure the uncertainty associated with decision making in the hopes of better understanding the rationale of decisions while optimizing the gain versus cost ratio. The goal is to calculate, within a series of decisions, the weight of their importance expressed in terms of usefulness or unpleasantness. In psychiatric therapeutics, only three studies have been published which incorporate the technique of decision trees. Two of these deal with treating depression (Schulberg et al., 1989; Koenig et al., 1993) while the third deals with schizophrenia (Hatcher, 1995). The limits of these techniques are, on one hand, due to their feasibility in that their complexity renders them inapplicable when a great number of variables have to be taken into account or when the amount of necessary data is still insufficient. Moreover, the use of these techniques remains relatively restricted as their expansion depends upon their acceptance by clinical physicians. Also, their use raises questions as to what extent it is possible to rationalize decisions in psychiatry. From a larger perspective, one must consider that these techniques may eventually furnish certain elements which could be integrated to help further the field of decision-making representations for clinical use. These decision-making techniques are still in the experimental stages and remains difficult to apply to clinical practice. However they appear to be of a great interest, not only in communicating knowledge both in teaching and training, but in research as well. They allow us to view the results of epidemiological studies and clinical research from a more global perspective; to make evident the grey areas of our science and to determine new priorities in research.

Decision Trees↗
PubMedDate not supplied

[Deficit in selective attention and its evolution in depression].

Selective attention was measured in 34 depressed patients and 34 controls using a computerized version of the Stroop test, that included a manipulation of the stimulus onset asynchrony (SCA) in order to explore the efficacy of cognitive inhibition as a function of depression and of clinical amelioration of degression after therapy. Clinical tests included a measure of psychomotor slowing [Echelle de Ralentissement de Widlöcher (ERD), the Hamilton (Psychiatric Rating Scale for Depression (HAMD), and the Brief Psychiatric Rating Scale (BPRS)]. Selective attention was measured with the Stroop test, which includes four measures: Word, Color, Color-Word, and Color-Word minus Color, or interference. All of these measures were deficient in the depressed patients, particularly Stroop interference. Even when additional time was given to inhibit the Stroop distractor in the SOA condition, depressed subjects still showed significantly inferior performance. After four weeks of anti-depressive treatment, fifteen of the patients were retested, and showed significant improvement on all the Stroop measures, particularly on Stroop interference. The improvement in performance on the attentional measures was comparable in magnitude to that seen on the clinical scales, and suggests that the interference measure can be a sensitive indicator of clinical status in depressed patients.

Adult↗