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Biomedical subjects

R M Post

Publications and source records attributed to R M Post.

At least 433 records · Page 24Linked to original sources

d-Amphetamine: effects on memory in a depressed population.

The effect of intravenous d-amphetamine on memory functions in a group of depressed patients was examined in a double-blind placebo-controlled study. Active drug administration resulted in an increase in verbal free recall but no change in cued recall, suggesting specific effects on memory processes. The level of psychological processing of the presented stimulus was shown to interact with drug-induced facilitation of recall. Improvement in memory of more shallowly processed material under amphetamine related significantly to subjects' base-line indices of noradrenergic function. Drug-induced changes in mood did not correlate with improvement in cognitive functioning. The interrelationships between biochemical determinants of mood and memory are discussed in light of these findings.

Bipolar Disorder↗

Effects of a dopamine agonist piribedil in depressed patients: relationship of pretreatment homovanillic acid to antidepressant response.

Piribedil, a compound that stimulates dopamine receptors in a relatively specific fashion, was administered to 11 hospitalized depressed patients. The dopamine agonist significantly decreased rapid eye movement (REM) sleep and percent REM sleep and increased REM latency. Piribedil decreased the probenecid-induced accumulation of the dopamine metabolite homovanillic acid (HVA) in CSF. A range of mild to moderate antidepressant effects was noted; one patient worsened and one developed recurrent manic episodes. The degree of improvement in depression was negatively correlated with pretreatment values of HVA in CSF (r = -.66, P less than .05). These data suggest that the heterogeneity of clinical response may be related to biological differences in depressed patients and that those with low initial dopaminergic function respond best to increased dopamine receptor stimulation.

Adult↗

Cerebrospinal fluid norepinephrine in affective illness.

The authors measured cerebrospinal fluid norepinephrine concentrations in manic, depressive, and neurological control patients with and without probenecid administration. Baseline and probenecid norepinephrine values were significantly higher in manic than in depressed patients, who did not differ significantly from the neurological patients. Depressed patients with high levels of anxiety had higher levels of norepinephrine than those with low anxiety. These data suggest that alterations in mood or motor activity may be associated with changes in central norepinephrine metabolism in man.

Anxiety↗

Immunoglobulins and viral antibodies in psychiatric patients.

The serum and CSF of 66 patients with functional psychoses were tested for immunoglobulins and antibodies to measles, HSV-I, CMV, and rubella viruses. Ten surgical and 80 neurological patients were controls. There were no significant findings in the serum, consistent with most previous studied. In the CSF 6 of 17 multiple admission schizophrenic patients had definite elevations of IgG or measles antibody and differed significantly from the surgical controls. Immunologically this group resembled the seriously ill neurological patients. No previous study has been made of immunoglobulins or viral antibodies in the CSF of psychiatric patients. It is concluded that further work is warranted in a search for biological subgroups of schizophrenia.

Adolescent↗

Kindling as a model for alcohol withdrawal syndromes.

Periodic brain stimulation, particularly in the limbic system, at stimulus intensities initially too low to produce any behavioural or EEG effects, progressively produces EEG changes, motor automatisms, and eventually convulsions, an effect called kindling. Data are presented and reviewed that suggest that the severity of alcohol withdrawal symptoms progressively increases over years of alcohol abuse in a stepwise fashion similar to the kindling process. The model is presented that the limbic system hyperirritability which accompanies each alcohol withdrawal serves over time to kindle increasingly widespread subcortical structures. These long-term changes in neuronal excitability might relate to the progression of alcohol withdrawal symptoms from tremor to seizures and delirium tremens, as well as the alcoholic personality changes between episodes of withdrawal.

Adolescent↗

Dopamine-beta-hydroxylase in the cerebrospinal fluid of psychiatric patients.

The activity of dopamine-beta-hydroxylase (DBH) in cerebrospinal fluid (CSF) from 59 psychiatric patients has been analyzed by a highly sensitive radio-enzymatic assay. There was no sex difference in DBH, but there was a significant positive correlation with age. Probenecid administration had no effect on CSF DBH. DBH in CSF correlated positively (r = 0.60) with the plasma enzyme. Among patients hospitalized for major depressive disorder, unipolar or bipolar, schizo-affective disorder, schizophrenia, alcoholism, or personality disorders there were no significant between-group differences. Among the patients with bipolar affective disorder, DBH activity from manic patients was significantly lower than that from depressed or euthymic patients. The results are discussed with reference to the theory that the amount of DBH in CSF may serve as an indicator of central noradrenergic activity.

Adolescent↗

Intravenous naloxone administration in schizophrenia and affective illness.

Fourteen schizophrenic patients and five patients with affective disorders were given naloxone (0.4 to 10 milligrams) or placebo intravenously in a double-blind fashion. Physicians' ratings of hallucinations, mannerisms and posturing, conceptual disorganization, psychosis, and mood did not change significantly. A single item, unusual thought content, improved significantly on the naloxone day compared to the placebo day. There was no improvement in mood in affectively ill patients rated either by themselves or by physicians. Naloxone did not markedly improve any patient studied, which suggests that the acute blockade of opiate receptors is not associated with global improvement in psychotic symptomatology.

Adolescent↗

Alterations in motor activity, sleep, and biochemistry in a cycling manic-depressive patient.

Biochemical and electrophysiological factors were studied longitudinally in a rapidly cycling manic-depressive patient. Slow changes in mood, motor activity, sleep, and urinary norepinephrine levels during the course of each depressed and manic episode are reported, as well as rapid alterations in many variables at the time of mood switch. Urinary concentrations of norepinephrine and its metabolite, 3-methoxy-4-hydroxyphenyl glycol (MHPG) were significantly lower in depression than in mania; norepinephrine but not MHPG excretion increased prior to the switch. We postulate that the slow behavioral and biological changes preceding switches in this patient are an important manifestation of the cyclic process in manic-depressive illness.

Adult↗

Cyclic AMP in cerebrospinal fluid of manic and depressive patients.

Cyclic 3',5'-adenosine monophosphate (c-AMP) was measured in cerebrospinal fluid (CSF) of manic and depressive patients with and without probenecid administration both before and during treatment with various psychotropic drugs. Oral probenecid (100 mg/kg) produced substantial c-AMP accumulations in CSF suggesting a probenecid-sensitive transport mechanism for c-AMP. Baseline and probenecid-induced accumulations of c-AMP were not significantly different in manic and depressed patients, while baseline levels in depressed patients were higher than those in neurological controls. Imipramine, amitriptyline, lithium, tryptophan, and electroconvulsant therapies did not significantly alter levels or accumulations of c-AMP in CSF of depressed patients.

Administration, Oral↗

Slow and rapid psychobiological alterations in a manic-depressive patient: clinical phenomenology.

A distinctive pattern of clinical change during eight affective episodes is reported in a rapidly cycling manic-depressive patient. After a rapid switch to near maximal intensity of affective symptoms, slow changes in symptomatology were documented by significant slopes and correlation coefficients over the course of each episode. Decreases in depression, anxiety, drowsiness, helplessness/hopelessness, anger, and sadness preceded the switches into mania; decreases in mania, euphoria, seeking others, and talking preceded the switches into depression. Psychologically important events appeared to regularly precede rapid mood switches. It is suggested that the consistent, slow clinical changes which occur during affective episodes may reflect part of an underlying rhthmic biological process and that environment events may be capable of triggering a final common pathway for the mood switch during a vulnerable period.

Adult↗