Biomedical subjects

Alan D Ogilvie

Publications and source records attributed to Alan D Ogilvie.

6 recordsLinked to original sources

PubMed2006

Heartbeat perception in depression.

Alterations in bodily awareness have been implicated in depression but there has been little detailed empirical characterisation of the degree and accuracy of body perception in the disorder. The present study examined the objective accuracy of heartbeat perception (using the Schandry mental tracking task) and the subjective degree of bodily focus (using the Bodily Consciousness Questionnaire; BCQ) in healthy control volunteers, a moderately depressed community sample, and a more severely depressed clinic sample (n=18 in each group). The community sample showed less accurate heartbeat perception than the control group as expected. Counter to prediction, however, the more severely depressed clinic sample performed better than the community depressed sample and equivalently to control volunteers on the Schandry task. There were no group differences on subjective bodily awareness. Implications for theories of depression are discussed.

Adult↗

PubMed2005

The subjective and cognitive effects of acute phenylalanine and tyrosine depletion in patients recovered from depression.

Although there is evidence for the involvement of dopamine (DA) in unipolar depression, no published study has yet used the technique of acute phenylalanine and tyrosine depletion (APTD), a dietary intervention that selectively lowers DA synthesis, in order to investigate the role of DA in mood disturbance. Tyrosine and phenylalanine depleted and placebo amino acid drinks were administered to 20 patients recovered from depression in a double-blind, placebo-controlled, crossover design. Measures included subjective effects, Hamilton Depression Rating Scale scores, and a comprehensive battery of well-validated computerized cognitive tests. APTD induced a substantial reduction in the ratio of plasma tyrosine and phenylalanine to large neutral amino acids. However, relapse of depressive symptoms was not seen. Although performance on most cognitive tests was unaffected, there was a selective effect on decision-making, with APTD causing participants to bet significantly less. In conclusion, These results suggest a specific role for the involvement of DA in reward/punishment processing in humans. While APTD did not induce relapse in any participant, it did cause patients recovered from depression to show lowered sensitivity to reward in a gambling game. It is hypothesized that tests involving reward/punishment processing are preferentially affected by DA depletion, and that a more complete account of depression is likely to result from considering the roles played by serotonin, noradrenaline, and DA in mediating the various cognitive and clinical symptoms, including anhedonia.

Adult↗

PubMed2005

The burden on informal caregivers of people with bipolar disorder.

Caregivers of people with bipolar disorder may experience a different quality of burden than is seen with other illnesses. A better understanding of their concerns is necessary to improve the training of professionals working with this population. Conceptualizing caregiver burden in a conventional medical framework may not focus enough on issues important to caregivers, or on cultural and social issues. Perceptions of caregivers about bipolar disorder have important effects on levels of burden experienced. It is important to distinguish between caregivers' experience of this subjective burden and objective burden as externally appraised. Caregivers' previous experiences of health services may influence their beliefs about the illness. Caregiver burden is associated with depression, which affects patient recovery by adding stress to the living environment. The objective burden on caregivers of patients with bipolar disorder is significantly higher than for those with unipolar depression. Caregivers of bipolar patients have high levels of expressed emotion, including critical, hostile, or over-involved attitudes. Several measures have been developed to assess the care burden of patients with depressive disorders, but may be inappropriate for patients with bipolar disorder because of its cyclical nature and the stresses arising from manic and hypomanic episodes. Inter-episode symptoms pose another potential of burden in patients with bipolar disorder. Subsyndromal depressive symptoms are common in this phase of the illness, resulting in severe and widespread impairment of function. Despite the importance of assessing caregiver burden in bipolar disorder, relevant literature is scarce. The specific effects of mania and inter-episode symptoms have not been adequately addressed, and there is a lack of existing measures to assess burden adequately, causing uncertainty regarding how best to structure family interventions to optimally alleviate burden. The relatively few studies into caregiver burden in bipolar disorder may largely reflect experiences in the US Veterans Affairs health service, but the findings may be limited in their generalizability. Nevertheless, available data suggest that caregiver burden is high and largely neglected in bipolar disorder. Clinically effective, well-targeted and practically viable interventions are needed. However, services cannot be enhanced on a rational basis without an improved understanding and capacity to measure and target caregiver burden the impact of any change in services be evaluated.

Affect↗

PubMed2005

The effect of bosentan on matrix metalloproteinase-9 levels in patients with systemic sclerosis-induced pulmonary hypertension.

OBJECTIVE: Systemic sclerosis (SSc) is an autoimmune disease that can potentially involve all tissues and organs of the human body. Based on the extent of the disease and organ involvement, different subsets of patients and organ involvement, different subsets of patients have been identified and several classifications proposed have been identified and several classifications proposed aiming to better stratify affected patients. The occurrence aiming to better stratify affected patients. The occurrence of pulmonary arterial hypertension (PAH), characterized of pulmonary arterial hypertension (PAH), characterized by altered tissue remodelling of the entire vessel wall, is the most severe complication that influences prognosis and survival. The molecular basis underlying the vascular damage is not yet known, but a family of enzymes named matrix metalloproteinases (MMPs), with a proteolytic activity towards several extra-cellular matrix (ECM) components, is likely to be involved. Recently, a dual inhibitor of endothelin-1, bosentan, has been successfully evaluated in clinical trials in PAH patients. RESEARCH DESIGN AND METHOD: The aim of this study is to investigate the expression of MMP-2 and MMP-9 in the serum of different subsets of SSc patients, and in patients treated with bosentan. Thirty-five Caucasian patients with SSc were enrolled in the study, 12 of whom were found to have isolated PAH assessed by Doppler echocardiography. Eight patients fully met the inclusion criteria and were eligible for therapy with bosentan given at the dosage of 62.5 mg twice daily for 4 weeks followed by 125 mg twice daily for 50 weeks(15). The remaining patients (4/12) initiated bosentan therapy for a few weeks and, therefore, were considered at the baseline level only. Serum samples were analysed by gelatine zymography. RESULTS: The results suggest that MMP-9 but not MMP-2 is differently expressed according to the degree of organ involvement. In particular, MMP-9 serum levels are significantly decreased in PAH with respect to other subsets of SSc patients. Moreover, in bosentan-treated patients, after 12 months of therapy MMP-9 significantly (p < 0.05) increased and correlated with an improved clinical outcome, as measured by the '6-minutes walking' test. CONCLUSIONS: This is the first time that MMP-9 serum levels are reported to be down-regulated in PAH patients and up-regulated following bosentan treatment. Whether MMP-9 has a pathogenetic role in the vascular damage observed in PAH patients or it is a marker of bosentan effectiveness is not yet known. However, MMP-9 may be an important molecule that needs further investigation in SSc patients to better define its role.

Adult↗

PubMed2004

Categorical and dimensional reports of experienced affect to emotion-inducing pictures in depression.

Self-reported affect to positive and negative emotional pictures was contrasted in people with major depressive disorder (MDD) and never-depressed control participants (n = 25 in each group). The results revealed significant differences in response to positive images (reduced arousal, less pleasant valence, decreased happiness, increased sadness) in MDD but no clear group differences in response to negative stimuli. Extending earlier findings of reduced responsiveness to positive, but not negative, stimuli in MDD (D. M. Sloan, M. E. Strauss, S. W. Quirk, & M. Satajovik, 1997; D. M. Sloan, M. E. Strauss, & K. L. Wisner, 2001), the data indicate that blunted response to positive stimuli is found when both categorical and dimensional ratings are elicited. Further, the data replicate earlier findings of elevated sadness reports to positive stimuli (J. Rottenberg, K. L. Kasch, J. J. Gross, & I. H. Gotlib, 2002), which may reflect broader difficulties in regulating emotions in MDD.

Affect↗

PubMed2004

Neuropsychological processing associated with recovery from depression after stereotactic subcaudate tractotomy.

OBJECTIVE: The authors compared patients who underwent stereotactic subcaudate tractotomy for depression, who were still depressed or recovered from depression, to identify therapeutic mechanisms. METHOD: Ten depressed and eight recovered psychosurgery patients, along with nine never-depressed subjects and nine who had recovered from depression with medication, completed the Iowa Gambling Task, a measure of decision making in the face of feedback. Psychosurgery patients also completed general neuropsychological testing. RESULTS: Recovered psychosurgery patients exhibited insensitivity to negative feedback on the Iowa Gambling Task compared to the other three groups. This difference between the groups remained when general neuropsychological performance was covaried out. CONCLUSIONS: These findings suggest acquired relative insensitivity to negative information as a specific mechanism mediating the antidepressant effect of stereotactic subcaudate tractotomy. Such insensitivity is not secondary to deficits in general neuropsychological functioning and is not a function of recovery from depression per se.

Adult↗