Differentiating 'clinical' and 'non-clinical' depression

OBJECTIVE

There has been increasing concern about extensions to the definition of 'clinical' depression, but little evident investigation as to how clinical and non-clinical depressive states might best be differentiated. This review considers the potential of many candidate symptom and non-symptom parameters.

METHOD

We overview representative concerns and theories about the nature of psychiatric disorders before reviewing the potential utility of candidate parameters for differentiating clinical and non-clinical depressive states.

RESULTS

While we detail limitations to all candidate parameters designed to distinguish between clinical and non-clinical depression, their actual utility may only be able to be judged by empirical testing across appropriate comparison groups.

CONCLUSION

We argue for initial comparisons being made between prototypically defined categorical (i.e. psychotic, melancholic and bipolar) depressive disease states and residual non-melancholic clinical depressive states, before considering how each of those two clinical subsets might differ from non-clinical depressive mood states.

Cleaving depressive diseases from depressive disorders and non-clinical states

OBJECTIVE

We sought to determine whether putative depressive diseases could be differentiated categorically from clinical depressive disorders and non-clinical mood states.

METHOD

We interviewed volunteers who reported or denied any lifetime depressive mood state and analyzed data from the former group reporting on their 'most severe' depressive episode. We employed latent class analysis (LCA) to determine whether a two-class solution was supported and the contribution of individual variables to class allocations.

RESULTS

All variables were significant predictors of class allocation. LCA-assigned Class I participants reported more depressive symptoms, had more distressing episodes and more lasting consequences, were more likely to view their depression as 'like a disease', and as being both disproportionately more severe and persistent in relation to any antecedent stressor. Validation involved comparison of LCA assignment with DSM-IV diagnosis for their most severe depressive episode. Of those assigned to Class I, 89% had a DSM diagnosis of melancholic, psychotic or bipolar depression. Class II had all those failing to meet criteria for a depressive episode and the majority of those with a non-melancholic depressive condition.

CONCLUSION

Despite not including individual depressive symptoms, study variables strongly differentiated putative depressive diseases from a composite of clinical depressive conditions and subclinical depressive states.

Is essential fatty acid status in late pregnancy predictive of post-natal depression?

OBJECTIVE

We tested the hypothesis that abnormal levels of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) during late pregnancy are associated with antenatal and post-natal depression.

METHOD

We interviewed a sample of more than 900 women in late pregnancy. We assessed whether they met criteria for depression on a standardized measure of post-natal depression [the Edinburgh Post-natal Depression Scale (EPDS)] and met DSM-IV criteria for major depression and/or were in receipt of antidepressant medication. Blood was collected at that time to generate data on nine PUFA variables. Sample members were re-interviewed post-natally to determine depressive experience in the 3 months following the birth of their baby.

RESULTS

Univariate associations were demonstrated between pre-natal depression categorized using DSM criteria and measures of blood fatty acids including total omega-3, the ratio of omega-6 to omega-3, docosahexaenoic acid (DHA) omega-3 and DHA plus eicosapentaenoic acid (EPA) omega-3. Such associations were not found post-natally, but different associations were quantified between EPDS-diagnosed depression and total omega-6, total omega-3 and EPA omega-3. In multivariate analyses, slight associations were maintained between EPDS and lower omega-3, lower EPA and higher omega-6 when neuroticism, stress during pregnancy, a lifetime episode of depression and older age were included in the analysis.

CONCLUSION

Findings in such a large sample indicate that PUFA status in late pregnancy is only slightly linked with the risk of post-natal depression when depression was quantified by the EPDS. There were no associations between post-natal depression diagnosed by DSM criteria and any fatty acid variables.

Computational hemodynamics analysis of intracranial aneurysms treated with flow diverters: correlation with clinical outcomes

BACKGROUND AND PURPOSE

Recent studies have shown promising results regarding intracranial aneurysms treated with flow diverters. However, these have had adverse effects, including delayed aneurysm occlusion, posttreatment symptoms, and rupture. The hemodynamic profiles of aneurysms treated with flow diverters were analyzed to determine the ones associated with successful and failed treatments.

MATERIALS AND METHODS

Patient-specific computational fluid dynamics were used to simulate hemodynamic profiles, including the presence of jet flow, energy loss, volume flow, and wall shear stress in 4 successful occlusions of aneurysms and 4 failed cases after flow-diverter deployment. In these 4 failed cases, hemodynamic profiles were examined again after a hypothetic second intervention. This involved replacing the failed flow diverter with a hypothetic optimally deployed flow diverter or simulated placement of a second flow diverter within the first (double hypothetic optimally deployed).

RESULTS

Where successful occlusions were achieved, a marked obliteration of jet flow was observed. Flow entering the aneurysm sac was diverted via the center of the flow diverter and joined smoothly with the continuation of flow leaving the aneurysm sac into the parent arteries. These observations were supplemented by a reduction in the other hemodynamic profiles. Aneurysm neck geometry might influence the efficacy of the flow diverter.

CONCLUSIONS

Hemodynamic indices, as calculated by using computational fluid dynamics techniques, have close correlation with flow-diverter treatment outcome. Computational fluid dynamics could be potentially useful as a planning tool for neurointerventionists by simulating an optimized flow-diverter deployment strategy before the procedure and evaluating posttreatment outcome.

The superiority of antidepressant medication to cognitive behavior therapy in melancholic depressed patients: a 12-week single-blind randomized study

OBJECTIVE

To pursue the previously long-standing but formally untested clinical view that melancholia is preferentially responsive to antidepressant medication in comparison with psychotherapy [specifically Cognitive Behavior Therapy (CBT)]. Second, to determine whether a broader action antidepressant medication sequencing regimen is superior to a Selective Serotonin Reuptake Inhibitor (SSRI) alone.

METHOD

We sought to recruit a large sample of participants with melancholic depression for a 12-week trial but inclusion criteria compromised recruitment and testing the second hypothesis. The first hypothesis was evaluated by comparing 18 participants receiving antidepressant medication to 11 receiving CBT. Primary study measures were the Hamilton Rating Scale for Depression (HAM-D) and the Hamilton Endogenous Subscale (HES), rated blindly, while several secondary measures also evaluated outcome.

RESULTS

Participants receiving medication had a superior 12-week outcome to those receiving CBT, with significant differences present on primary measures as early as 4 weeks. At trial conclusion, the percentage improvement in HAM-D scores was 61.1% vs. 34.4%, respectively [Number Needed to Treat (NNT) = 3.7] and with those in receipt of medication returning non-significantly higher HAM-D responder (66.6% vs. 36.4%, NNT = 2.8) and remission (66.7% vs. 45.4%, NNT = 4.7) rates.

CONCLUSION

As the sample size was small and participants evidenced only moderate levels of depression severity, the study risked being underpowered and idiosyncratic. Despite the small sample, the superiority of antidepressant medication to CBT in those with a melancholic depression was distinctive in this pilot study.

The 'real world' utility of a web-based bipolar disorder screening measure

OBJECTIVE

To determine whether those completing a self-report bipolar self-test measure and identified as having a likely bipolar disorder judged the self-test as useful and had a subsequent superior illness course.

METHOD

We invited those completing the web-based Mood Swings Questionnaire (or MSQ) to provide contact details and contribute to a 3-month study evaluating their responses to being identified as having a likely bipolar disorder, any subsequent action taken and the impact of such actions on their illness trajectory.

RESULTS

We analysed data received from 665 participants screening 'positive' on the MSQ and completing baseline and 3-month follow-up data. High rates of satisfaction with the MSQ were quantified, with respondents viewing the measure as informative, validating and/or motivating. Of those receiving a confirmed bipolar diagnosis, such clarification occurred on average 12 years after their first depressive episode. Most implemented self-management strategies irrespective of whether seeking formal diagnostic clarification or not. Participants improved on depressive, quality of life and overall functioning measures over the study period, but with results indicating (via analysis of three sample subsets differing by the degree of 'actions taken') that those who took assertive action and had the diagnosis confirmed had the most superior outcome.

CONCLUSION

This is the first study to formally evaluate the clinical impact of a self-report bipolar disorder screening measure. High acceptance and superior outcomes quantified for those acting assertively in response to such a new diagnosis argue for its 'real world' utility.

Systematic review of international evidence on the effectiveness and costs of paediatric home care for children and young people who are ill

Promoting 'care closer to home' for ill children is a policy and practice objective internationally. Progress towards this goal is hampered by a perceived lack of evidence on effectiveness and costs. The aim of the work reported here was to establish the strength of current international evidence on the effectiveness and costs of paediatric home care by updating and extending an earlier systematic review. A systematic review following Centre for Reviews and Dissemination guidelines involved updating electronic searches, and extending them to cover paediatric home care for short-term acute conditions. Twenty-one databases were searched from 1990 to April 2007. Hand searching was also carried out. Pairs of team members, guided by an algorithm, selected randomized controlled trials (RCTs), other comparative studies and studies including health economics data. A third reviewer resolved any disagreements. The quality of RCTs was assessed, but a 'best-evidence' approach was taken overall. Data were extracted into specifically designed spreadsheets and a second team member checked all data. Narrative synthesis was used throughout. This paper reports findings from RCTs and studies with health economics data. In total, 16 570 publications were identified after de-duplication. Eleven new RCTs (reported in 17 papers) and 20 papers with health economics data were included and reviewed. Evidence on costs and effectiveness of paediatric home care has not grown substantially since the previous review, but this updated review adds weight to the conclusion that it can deliver equivalent clinical outcomes for children and not impose a greater burden on families. Indeed, in some cases, there is evidence of reduced burden and costs for families compared with hospital care. There is also growing evidence, albeit based on weaker evidence, that paediatric home care may reduce costs for health services, particularly for children with complex and long-term needs.

Imaging vascular function for early stage clinical trials using dynamic contrast-enhanced magnetic resonance imaging

Many therapeutic approaches to cancer affect the tumour vasculature, either indirectly or as a direct target. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has become an important means of investigating this action, both pre-clinically and in early stage clinical trials. For such trials, it is essential that the measurement process (i.e. image acquisition and analysis) can be performed effectively and with consistency among contributing centres. As the technique continues to develop in order to provide potential improvements in sensitivity and physiological relevance, there is considerable scope for between-centre variation in techniques. A workshop was convened by the Imaging Committee of the Experimental Cancer Medicine Centres (ECMC) to review the current status of DCE-MRI and to provide recommendations on how the technique can best be used for early stage trials. This review and the consequent recommendations are summarised here. Key Points • Tumour vascular function is key to tumour development and treatment • Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can assess tumour vascular function • Thus DCE-MRI with pharmacokinetic models can assess novel treatments • Many recent developments are advancing the accuracy of and information from DCE-MRI • Establishing common methodology across multiple centres is challenging and requires accepted guidelines.

Is context everything to the definition of clinical depression? A test of the Horwitz and Wakefield postulate

BACKGROUND

In arguing for the need to distinguish clinical depression from sadness, Horwitz and Wakefield argued for weighting consideration to nuances of life event stressors. Their definition of clinical depression corresponds to the concept of endogenous depression or melancholia, while their model would position reactive (or context specific) non-melancholic depressive disorders more as manifestations of 'sadness' rather than as clinical depression.

METHOD

We test their postulate by examining the extent to which 141 clinically diagnosed melancholic and non-melancholic depressed patients reported episodes as being preceded by a life event stressor or not--and the salience of any life stressor to episode onset and severity.

RESULTS

While melancholic patients were more likely than non-melancholic patients to report episodes coming 'out of the blue' and to be more severe than might be expected from the severity of antecedent stressors, differences were more ones of degree and not absolute. Such context variables appeared, however, to differentiate melancholic and non-melancholic patients more consistently than depression symptom variables. As depression severity and impairment levels did not differ across the melancholic and non-melancholic patients, findings were unlikely to be artefacts of such factors.

CONCLUSIONS

The study finds some support for the Horwitz and Wakefield hypothesis of clinical (or, at least melancholic) depression requiring independence of context or an antecedent stressor, but with precision likely to be compromised by nuances intrinsic to assessment of life event stressors and their contribution to depression onset, difficulties in defining valid 'melancholic' and 'non-melancholic' depressive sub-groups and the parsimony of the hypothesis.

Mood effects of the amino acids tryptophan and tyrosine: 'Food for Thought' III

OBJECTIVE

Reflecting increased scientific interest in any nutritional contribution to the onset and treatment of mood disorders, we overview research into two neurotransmitter precursors - the amino acids tryptophan and tyrosine - particularly examining whether any deficiency increases risk to depression and whether those amino acids have any antidepressant properties.

METHOD

The theoretical relevance of the two amino acids was overviewed by considering published risk and intervention studies, technical papers and reviews.

RESULTS

There is some limited evidence, suggesting that depressed patients, especially those with a melancholic depression, have decreased tryptophan levels. Whether such findings reflect a causal contribution or are a consequence of a depressed state remains an open question. There is a small database supporting tryptophan preparations as benefitting depressed mood states. There is no clear evidence as to whether tyrosine deficiency contributes to depression, while the only randomized double-blind study examining tyrosine supplementation did not show antidepressant benefit.

CONCLUSION

Acute tryptophan depletion continues to provide a research tool for investigating the relevance of serotonin to depression onset. There is limited evidence that tryptophan loading is effective as a treatment for depression through its action of increasing serotonin production. Most clinical studies are dated, involve small sample sizes and/or were not placebo controlled. The development of the new serotonin reuptake inhibitor drugs seemingly signalled an end to pursuing such means of promoting increased serotonin as a treatment for depression. The evidence for tyrosine loading promoting catecholamine production as a possible treatment for depression appears even less promising, and depletion studies less informative.

'D' for depression: any role for vitamin D? 'Food for Thought' II

OBJECTIVE

While there has long been interest in any nutritional contribution to the onset and treatment of mood disorders, there has been increasing scientific evaluation of several candidate nutritional and dietary factors in recent years. In this paper, we overview research into any vitamin D insufficiency and deficiency contribution to depression.

METHOD

The relevant literature was reviewed.

RESULTS

Cross-sectional studies have identified associations between depression and low vitamin D levels, but studies have failed to clarify whether vitamin D deficiency is an antecedent cause, correlate or consequence of depression. While vitamin D deficiency and insufficiency have been linked with seasonal affective disorder, suggested associations have not been rigorously tested. There has been insufficient research to establish whether and when vitamin D supplementation should be considered as an augmentation strategy with antidepressant drugs.

CONCLUSION

There is currently insufficient evidence to argue strongly for vitamin D supplementation in patients with depression, but such a strategy is worthy of consideration in depressed patients whose lifestyle and geographical residence may indicate a risk of vitamin D insufficiency--or where low vitamin D levels have been quantified.