Kerrie Eyers

Bio: Kerrie Eyers is an academic researcher from University of New South Wales. The author has contributed to research in topics: Melancholia & Referral. The author has an hindex of 13, co-authored 25 publications receiving 1214 citations. Previous affiliations of Kerrie Eyers include Black Dog Institute.

Cognitive function in depression: a distinct pattern of frontal impairment in melancholia?

Abstract: Background Although depressed patients demonstrate impaired performance on a range of neuropsychological tests, there is little research that examines either frontal cognitive deficits or possible differences in test performance between melancholic and non-melancholic subtypes. Methods Depressed subjects were administered a broad neuropsychological battery. In an overall analysis, 77 depressed subjects were compared with 28 controls. In a second set of analyses, the depressed sample was divided into melancholic and non-melancholic subsets according to DSM-III-R, the CORE system and the Newcastle scale. These depressed subsets were contrasted to controls and with each other using ANCOVA controlling for age, IQ, simple reaction time and Hamilton Depression scores where appropriate. Results The total depressed sample was impaired on most mnemonic tasks, simple reaction time and Trails B. Similar findings applied to DSM-III-R melancholic and non-melancholic subjects. When defined by the CORE and Newcastle (narrower definitions of melancholia), melancholic patients were additionally impaired on WCST (perseverative response) and (for Newcastle) digit symbol substitution. In contrast, the cognitive performance of the CORE and Newcastle-defined non-melancholic patients was largely unimpaired. Conclusions Using narrower definitions of melancholia, i.e. CORE and (in particular) Newcastle, melancholic patients were impaired on mnemonic tasks and tasks of selective attention, and set-shifting while non-melancholic subjects were largely unimpaired in their cognitive performance. These differences may be due to impairment of specific neuroanatomical regions in narrowly defined melancholic patients, in particular the anterior cingulate.

Defining melancholia: properties of a refined sign-based measure.

Abstract: We hypothesised that psychomotor disturbance is specific to the melancholic subtype of depression and capable of defining melancholia more precisely than symptom-based criteria sets. We studied 413 depressed patients, and examined the utility of a refined, operationally driven set of clinician-rated signs, principally against a set of historically accepted symptoms of endogeneity. We specified items defining psychomotor disturbance generally as well as those weighted either to agitation or to retardation. We demonstrated the system's capacity to differentiate 'melancholic' and 'non-melancholic' depression (and the comparable success of DSM-III-R and Newcastle criteria systems) by reference to several patient, illness and treatment response variables, to an independent measure of psychomotor disturbance (reaction time) and to a biological marker (the dexamethasone suppression test).

Prognosis of depression in the elderly. A comparison with younger patients.

Abstract: The prognosis of depression in the elderly was investigated in a mixed-age sample of 242 consecutive referrals, with DSM-III defined unipolar major depressive episode, to a specialist unit for mood disorders. Subjects were followed up at about 1 and 3.8 years. There was no significant difference in outcome between younger (under 40 years), middle aged (40-59 years) and older (60 years or more) depressed patients. For the 61 elderly subjects with depression, prognosis improved with time, with 25% having a lasting recovery at the first and 41% at the second follow-up. Early onset, recurrence, and poor premorbid personality were associated with a worse prognosis. Three (5%) elderly depressives had committed suicide and seven (11%) had died from natural causes by the second follow-up. Despite some methodological limitations, our findings suggest a more optimistic outlook and the need for longer, more assertive treatment for elderly, depressed patients.

Classifying depression by mental state signs.

Abstract: The possibility that separation of a categorical depressive disease ('melancholia') from remaining depressive disorders can be improved by assessment of mental state signs was examined in patients treated by representative Sydney psychiatrists and patients referred to a specialised mood disorders unit. A set of signs, principally assessing retardation, was derived within the two samples by principal-components and latent-class analyses. Scores were significantly correlated with clinical, DSM-III, and RDC diagnoses, and appeared independent of severity, suggesting that melancholia can be defined phenomenologically. Scores were also associated with several 'validating' factors. Comparative analyses of a refined list of melancholia symptoms suggested that ratings of defined signs are likely to have greater capacity than symptom ratings to differentiate melancholia from residual depressive disorders.

Major Depressive Disorder Is Associated With Broad Impairments on Neuropsychological Measures of Executive Function: A Meta-Analysis and Review

Abstract: Cognitive impairments are now widely acknowledged as an important aspect of major depressive disorder (MDD), and it has been proposed that executive function (EF) may be particularly impaired in patients with MDD. However, the existence and nature of EF impairments associated with depression remain strongly debated. Although many studies have found significant deficits associated with MDD on neuropsychological measures of EF, others have not, potentially due to low statistical power, task impurity, and diverse patient samples, and there have been no recent, comprehensive, meta-analyses investigating EF in patients with MDD. The current meta-analysis uses random-effects models to synthesize 113 previous research studies that compared participants with MDD to healthy control participants on at least one neuropsychological measure of EF. Results of the meta-analysis demonstrate that MDD is reliably associated with impaired performance on neuropsychological measures of EF, with effect sizes ranging from 0.32 to 0.97. Although patients with MDD also have slower processing speed, motor slowing alone cannot account for these results. In addition, some evidence suggests that deficits on neuropsychological measures of EF are greater in patients with more severe current depression symptoms, and those taking psychotropic medications, whereas evidence for effects of age was weaker. The results are consistent with the theory that MDD is associated with broad impairment in multiple aspects of EF. Implications for treatment of MDD and theories of EF are discussed. Future research is needed to establish the specificity and causal link between MDD and EF impairments.

Cognitive deficits in depression: possible implications for functional neuropathology.

Abstract: Background While depression is known to involve a disturbance of mood, movement and cognition, its associated cognitive deficits are frequently viewed as simple epiphenomena of the disorder. Aims To review the status of cognitive deficits in depression and their putative neurobiological underpinnings. Method Selective computerised review of the literature examining cognitive deficits in depression and their brain correlates. Results Recent studies report both mnemonic deficits and the presence of executive impairment — possibly selective for set-shifting tasks — in depression. Many studies suggest that these occur independent of age, depression severity and subtype, task ‘difficulty’, motivation and response bias: some persist upon clinical ‘ recovery’. Conclusions Mnemonic and executive deficits do no appear to be epiphenomena of depressive disorder. A focus on the interactions between motivation, affect and cognitive function may allow greater understanding of the interplay between key aspects of the dorsal and ventral aspects of the prefrontal cortex in depression.