PubMed Health⌕ Search

Biomedical subjects

F M Jacobsen

Publications and source records attributed to F M Jacobsen.

At least 37 records · Page 2Linked to original sources

Comparative anxiogenic, neuroendocrine, and other physiologic effects of m-chlorophenylpiperazine given intravenously or orally to healthy volunteers.

The serotonin agonist m-chlorophenylpiperazine (m-CPP) had greater anxiogenic and other mood and cognitive effects when administered intravenously (0.1 mg/kg) rather than orally (0.5 mg/kg) to healthy subjects. Nonetheless, similar elevations in peak plasma cortisol and prolactin concentrations were obtained with the two dosage regimens, and temperature elevations were greater after oral m-CPP. Plateau phase plasma concentrations of m-CPP at the times of the maximum neuroendocrine responses to intravenous and oral m-CPP were similar. Since all rodent and nonhuman primate studies have used parenterally administered m-CPP, and previous clinical investigations using intravenous rather than oral m-CPP have yielded somewhat discrepant results, our normative data should be useful for comparing results across different human studies and across species.

Administration, Oral↗

Evidence for a decline with age in behavioral responsivity to the serotonin agonist, m-chlorophenylpiperazine, in healthy human subjects.

The functional significance of alterations in brain serotonin (5HT) associated with normal aging in both animals and humans is largely unknown. Using the effects of the 5HT agonist, m-chlorophenylpiperazine (m-CPP), as a measure of central serotonergic responsivity, we compared the behavioral and neuroendocrine responses of older normal volunteers (mean age +/- SD = 62.4 +/- 4.12) to those of younger normal volunteers (mean age +/- SD = 31.6 +/- 5.52). When m-CPP was administered intravenously, older subjects showed decreased behavioral responses but similar neuroendocrine responses, compared to younger subjects. The decreased behavioral responsivity was unrelated to pharmaco-kinetic differences between the groups, since m-CPP plasma levels were similar in both groups. This report is the first in vivo study in humans to demonstrate decreased behavioral responsivity with age following serotonergic stimulation, and may indicate a functionally less responsive 5HT subsystem in older subjects.

Adult↗

Atenolol in seasonal affective disorder: a test of the melatonin hypothesis.

To test the hypothesis that the antidepressant effects of bright light in seasonal affective disorder are mediated by the suppression of melatonin, 19 patients with this disorder were given atenolol, which suppresses melatonin secretion, and placebo in a double-blind crossover study. No difference in antidepressant efficacy was found between drug and placebo in the sample as a whole, which argues against the melatonin hypothesis of phototherapy. However, in three of the patients atenolol provided repeated, marked, and sustained relief of symptoms, suggesting that it may be useful in treating the winter depressive symptoms of some patients with seasonal affective disorder.

Adult↗

Neuroendocrine response to 5-hydroxytryptophan in seasonal affective disorder.

A double-blind random-ordered comparison of the effects of placebo and 5-hydroxytryptophan (200 mg, orally) in ten depressed patients with seasonal affective disorder (SAD) and ten controls disclosed slightly but significantly higher basal levels of serum prolactin and a trend toward higher basal levels of serum cortisol in the patients with SAD compared with controls. After administration of 5-HTP, the cortisol level significantly increased and the prolactin level significantly decreased in both patients and controls. No differences in the melatonin level, growth hormone level, blood pressure, or pulse rate and no side effects were noted between patients and controls in the two study conditions; the timing of basal and 5-hydroxytryptophan-stimulated hormonal secretions was similar for both groups. These results are discussed with reference to current hypotheses of the cause of SAD.

5-Hydroxytryptophan↗

No mood-altering effects found after treatment of normal subjects with bright light in the morning.

Studies have shown that depressed patients with seasonal affective disorder (SAD) respond to treatment with bright artificial light. In this study 2 hours of bright artificial light administered in the morning for 1 week did not alter mood in 11 normal subjects. This finding suggests that the mood-enhancing effect of light for SAD patients is not necessarily generalizable to other populations.

Affect↗

Ethnocultural identification in psychotherapy.

Ethnoculturally translocated individuals, members of minority groups, and patients in cross-cultural psychotherapy frequently experience disturbances of their ethnocultural identities. During psychotherapy these patients often attribute ethnocultural qualities to their therapists in a process called ethnocultural identification. This process may be used to foster a therapeutic identification in which the therapist reflects pieces of the patient's conflicted ethnocultural identity. Cases are presented here illustrating the use of ethnocultural identification as an auxiliary therapeutic tool to facilitate coping with changing cultural values and transitional experiences, and to promote the integration of the ethnocultural self into a consolidated sense of identity.

Acculturation↗

Morning versus midday phototherapy of seasonal affective disorder.

Sixteen depressed patients with seasonal affective disorder participated in a double-blind crossover study comparing the antidepressant effects of 2 hours of early morning and 2 hours of early afternoon therapy with bright light. They responded equally well to both treatments. These results suggest that the antidepressant effects of phototherapy in seasonal affective disorder do not depend on its capacity to extend day length (photoperiod) and are not likely to be due to a shift in the timing of circadian rhythms. These findings have practical implications for the administration of phototherapy in the treatment of seasonal affective disorder.

Circadian Rhythm↗

Eye versus skin phototherapy of seasonal affective disorder.

In winter, depressed patients with seasonal affective disorder respond to treatment with bright artificial light (phototherapy). The authors found that the antidepressant effects of phototherapy were much greater for 10 patients when light was applied to the eyes than when it was applied to the skin, suggesting that its effects may be mediated by the eyes. The identification of a probable anatomical route of entry is clinically relevant and an important clue for further investigations of the mechanism of phototherapy. However, patients' expectations nearly always predicted the outcome, leaving open the possibility that expectations were responsible for their responses.

Attitude to Health↗

Seasonal affective disorder: a review of the syndrome and its public health implications.

Seasonal affective disorder (SAD) is a disturbance of mood and behavior which resembles some seasonal changes seen in lower mammals. Like these animal seasonal changes, SAD is thought to be related to decreased sunlight during winter months. [SAD has been successfully treated with exposure to bright artificial light of higher intensity than is usually present in the home or workplace. Many people not suffering from SAD may nonetheless have seasonal changes which could be helped by environmental light supplementation. Lighting standards in the home and workplace should be re-evaluated on the basis of new knowledge of the psychobiological effects of light.] We review the literature on SAD and discuss its public health implications in the context of a typical case presentation.

Adult↗

Phototherapy of seasonal affective disorder. Time of day and suppression of melatonin are not critical for antidepressant effects.

Seasonal affective disorder is characterized by recurring cycles of fall-winter depression and spring-summer hypomania (or euthymia). In winter, depressed patients with seasonal affective disorder respond to daily treatments with five to six hours of bright artificial light in two to three days. They relapse two to three days after light is withdrawn. In this study carefully controlled experimental conditions were used to determine whether phototherapy acts via a photoperiodic mechanism in which the timing of light is critical for its therapeutic effect. Photoperiodism is a common regulatory mechanism in animal seasonal rhythms and depends for its effect on light-induced changes in the pattern of nocturnal melatonin secretion. The results reported herein of "skeleton photoperiod" experiments indicate that the efficacy of phototherapy may not depend on its timing or its effect on melatonin secretion.

Circadian Rhythm↗

Melatonin in seasonal affective disorder and phototherapy.

In several studies we have found that treatment with bright environmental light, capable of suppressing human melatonin, reverses the winter depressive symptoms of patients with seasonal affective disorder (SAD), whereas light too dim to suppress human melatonin is therapeutically ineffective. This finding, as well as the central importance of melatonin as a hormonal mediator of photoperiodic changes on seasonal rhythms in animals, led us to test the hypothesis that melatonin mediates the effects of shortening days on the winter symptoms of SAD and that the modification of melatonin secretion by bright light mediates its antidepressant effects. We partially reversed the antidepressant effects of phototherapy in 8 SAD patients by oral melatonin administration, but in another study of 19 SAD patients we failed to find any therapeutic difference between the beta-adrenergic blocker, atenolol, which inhibits melatonin secretion, and placebo. In a third study of 7 SAD patients we showed that the anti-depressant effects of phototherapy were not photoperiodic and appeared to be independent of melatonin suppression. There is some preliminary evidence that melatonin secretion may be abnormal in SAD. We conclude that while melatonin may play some role in the symptoms of SAD and the effects of phototherapy, it cannot by itself account for these phenomena.

Animals↗