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Magnetic resonance imaging in late-life depression: vascular and glucocorticoid cascade hypotheses.
BACKGROUND: Late-life depression is a common and heterogeneous illness, associated with structural abnormalities in both grey and white matter. AIMS: To examine the relationship between age at onset and magnetic resonance imaging (MRI) measures of grey and white matter to establish whether they support particular hypotheses regarding the anatomy and aetiology of network disruption in late-life depression. METHOD: We studied 36 participants with late-life depression. Grey matter was examined using T(1)-weighted MRI and analysed using voxel-based morphometry. The hippocampus was automatically segmented and volume and shape analysis performed. White matter was examined using diffusion tensor imaging and analysed using tract-based spatial statistics. RESULTS: Later age at onset was significantly associated with reduced fractional anisotropy of widespread tracts, in particular the anterior thalamic radiation and superior longitudinal fasciculus. Earlier age at onset was associated with reduced hippocampal volume normalised to whole brain size bilaterally. However, no significant correlations were detected using hippocampal shape analysis or voxel-based morphometry. CONCLUSIONS: Overall, the results were compatible with the vascular hypothesis, and provided some support for the glucocorticoid cascade hypothesis.
Clinical amyloid imaging in Alzheimer's disease.
BACKGROUND: The hypothesis that amyloid deposition is the leading cause of Alzheimer's disease (AD) is supported by findings in transgenic animal models and forms the basis of clinical trials of anti-amyloid agents. According to this theory, amyloid deposition causes severe damage to neurons many years before onset of dementia via a cascade of several downstream effects. This hypothesis has, however, not yet been directly tested in human beings because of the very limited possibility of diagnosing amyloid deposition in vivo, which until recently required either brain biopsy or PET imaging with an on-site cyclotron and radiochemistry laboratory. Moreover, a clinical diagnosis of AD requires that patients have dementia, at which stage any effective treatment aimed at reducing amyloid deposition will probably be too late. RECENT DEVELOPMENTS: The amyloid imaging tracers flutemetamol, florbetapir, and florbetaben labelled with (18)F have been developed for PET; they can be produced commercially at central cyclotron sites and subsequently delivered to clinical PET scanning facilities. These tracers are currently undergoing formal clinical trials to establish whether they can be used to accurately image fibrillary amyloid and to distinguish patients with AD from normal controls and those with other diseases that cause dementia. They might also be used as biomarkers to predict development of AD before onset of dementia and to assess the effect of anti-amyloid therapy. Negative amyloid scans indicate absence of AD with a high level of accuracy, but healthy elderly volunteers might have positive amyloid scans, so their predictive value in isolation is less clear. Close association of in-vivo amyloid imaging results with post-mortem histopathological findings was shown with florbetapir in a phase 3 study. WHERE NEXT?: Therapeutic studies of anti-amyloid agents that include amyloid tracers as biomarkers are expected to be useful for drug development and to clarify the relation between amyloid removal and clinical effects. Once the (18)F tracers become available for diagnostic use, large-scale longitudinal studies will be needed to clarify their prognostic and diagnostic power in relation to age, risk factors, and AD subtypes. Ultimately, these tracers will hopefully clarify the pathophysiological role of amyloid in AD and contribute to development of new treatments.
Wake-up call for British psychiatry.
The recent drive within the UK National Health Service to improve psychosocial care for people with mental illness is both understandable and welcome: evidence-based psychological and social interventions are extremely important in managing psychiatric illness. Nevertheless, the accompanying downgrading of medical aspects of care has resulted in services that often are better suited to offering non-specific psychosocial support, rather than thorough, broad-based diagnostic assessment leading to specific treatments to optimise well-being and functioning. In part, these changes have been politically driven, but they could not have occurred without the collusion, or at least the acquiescence, of psychiatrists. This creeping devaluation of medicine disadvantages patients and is very damaging to both the standing and the understanding of psychiatry in the minds of the public, fellow professionals and the medical students who will be responsible for the specialty's future. On the 200th birthday of psychiatry, it is fitting to reconsider the specialty's core values and renew efforts to use psychiatric skills for the maximum benefit of patients.
Memory impairment in out-of-hospital cardiac arrest survivors is associated with global reduction in brain volume, not focal hippocampal injury.
BACKGROUND AND PURPOSE: More than 30% of out-of-hospital cardiac arrest (OHCA) survivors suffer significant memory impairment. The hippocampus may be vulnerable to hypoxic injury during cardiac arrest. The purpose of this study was to determine whether selective hippocampal injury is the substrate for this memory impairment. METHODS: Seventeen OHCA survivors and 12 patients with uncomplicated myocardial infarction were studied. OHCA survivors were divided into those with impaired and intact memory. Memory was assessed by use of the Rivermead Behavioural Memory Test and Doors and People Test. MRI was used to determine intracranial, whole-brain, amygdala-hippocampal complex, and temporal lobe volumes. Brain structure was also examined by statistical parametric mapping. RESULTS: Left amygdala-hippocampal volume was reduced in memory-impaired OHCA victims compared with control subjects (mean 3. 93 cm(3) and 95% CI 3.50 to 4.36 cm(3) versus mean 4.65 cm(3) and 95% CI 4.37 to 4.93 cm(3); P=0.002). Left temporal lobe and whole-brain volumes were also reduced. There were no differences in amygdala-hippocampal volume indexed against ipsilateral temporal lobe volume. Significant correlations were observed between total brain volume and Rivermead Behavioural Memory Test (r=0.56, P<0.05) and Doors and People Test (r=0.67, P<0.01) scores in OHCA survivors. Both recall and recognition were compromised in memory-impaired subjects. Statistical parametric mapping did not detect focal brain abnormalities in these subjects. Global cerebral atrophy was confirmed by qualitative assessment. CONCLUSIONS: Memory impairment in OHCA survivors is associated with global cerebral atrophy, not selective hippocampal damage. Rehabilitation protocols need to account for the global nature of the brain injury.
Reduced in vivo binding to the serotonin transporter in the cerebral cortex of MDMA ('ecstasy') users.
BACKGROUND: The use of MDMA ('ecstasy') is common among young people in Western countries. Animal models of MDMA toxicity suggest a loss of serotonergic neurons, and potentially implicate in the development of significant psychiatric morbidity in humans. AIMS: To test whether long-term use of MDMA can produce abnormalities in cerebral serotonin, but not dopamine, transporter binding measured by single photon emission computed tomography (SPECT). METHOD: Ten male regular ecstasy users and 10 well-matched controls recruited from the same community sources participated in SPECT with the serotonin transporter (SERT) ligand [123I] beta-CIT. Dopamine transporter binding was determined from scans acquired 23 hours after injection of the tracer. RESULTS: Ecstasy users showed a cortical reduction of SERT binding, particularly prominent in primary sensory-motor cortex, with normal dopamine transporter binding in lenticular nuclei. CONCLUSIONS: This cross-sectional association study provides suggestive evidence for specific, at least temporary, serotonergic neurotoxicity of MDMA in humans.
The effect of anxiety induction on the regional uptake of 99mTc-exametazime in simple phobia as shown by single photon emission tomography (SPET).
Ten patients suffering from DSM-III-R simple phobia were studied under two conditions: (a) while listening to a 4 min relaxation tape, and (b) while listening to a 4 min audio tape describing exposure to the phobic stimulus. During each condition, subjects were injected with 99mTc-Exametazime, a marker of regional cerebral blood flow. Subjective and psychophysiological measures indicated a marked effect of the anxiety induction procedure. Ratio analysis of the SPET data revealed reductions in tracer uptake largely confined to posterior cerebral regions bilaterally. Analysis of brain regions of interest normalised to the whole brain slice showed reductions confined to right temporal/occipital regions. In general there was no clear association between subjective and physiological variables and changes in regional uptake of tracer as a consequence of the anxiety induction procedure. The changes in tracer uptake were dissimilar to those previously reported for other cognitive activation paradigms, providing some reassurance that those functional brain changes were not artefacts of non-specific changes in state anxiety. These posterior brain changes may reflect alterations in activation of the GABA/benzodiazepine complex.
Does idiopathic parkinsonism in Aberdeen follow intrauterine influenza?
A study is presented which fails to replicate a recent report that peak years of birth of patients later developing Parkinson's disease are related to the influenza pandemics of the period 1890-1930. The years of birth of a whole population cohort of 243 patients suffering from Parkinson's disease examined in Aberdeen in 1983 and reexamined in 1986/7 were compared with deaths due to influenza in the City of Aberdeen in the years 1900-1930. Although a significant peak of Parkinson births (compared with the age profile of the Aberdeen population in 1983) occurred in 1902, there appeared to be no systematic relationship between Parkinson births and influenza deaths. In addition, no season of birth effect could be detected in a comparison with 232 matched controls. The presence of peaks of birth years, for whatever aetiological reason, is of significance to epidemiological studies in that prevalence estimates may be influenced by the year of study relative to these mini-cohorts.
Exploring the pattern and neural correlates of neuropsychological impairment in late-life depression.
BACKGROUND: Neuropsychological impairment is a key feature of late-life depression, with deficits observed across multiple domains. However, it is unclear whether deficits in multiple domains represent relatively independent processes with specific neural correlates or whether they can be explained by cognitive deficits in executive function or processing speed. METHOD: We examined group differences across five domains (episodic memory; executive function; language skills; processing speed; visuospatial skills) in a sample of 36 depressed participants and 25 control participants, all aged ≥ 60 years. The influence of executive function and processing speed deficits on other neuropsychological domains was also investigated. Magnetic resonance imaging correlates of executive function, processing speed and episodic memory were explored in the late-life depression group. RESULTS: Relative to controls, the late-life depression group performed significantly worse in the domains of executive function, processing speed, episodic memory and language skills. Impairments in executive function or processing speed were sufficient to explain differences in episodic memory and language skills. Executive function was correlated with anisotropy of the anterior thalamic radiation and uncinate fasciculus; processing speed was correlated with anisotropy of genu of the corpus callosum. Episodic memory was correlated with anisotropy of the anterior thalamic radiation, the genu and body of the corpus callosum and the fornix. CONCLUSIONS: Executive function and processing speed appear to represent important cognitive deficits in late-life depression, which contribute to deficits in other domains, and are related to reductions in anisotropy in frontal tracts.
Evidence-based guidelines for treating bipolar disorder: revised second edition--recommendations from the British Association for Psychopharmacology.
The British Association for Psychopharmacology guidelines specify the scope and target of treatment for bipolar disorder. The second version, like the first, is based explicitly on the available evidence and presented, like previous Clinical Practice guidelines, as recommendations to aid clinical decision making for practitioners: they may also serve as a source of information for patients and carers. The recommendations are presented together with a more detailed but selective qualitative review of the available evidence. A consensus meeting, involving experts in bipolar disorder and its treatment, reviewed key areas and considered the strength of evidence and clinical implications. The guidelines were drawn up after extensive feedback from participants and interested parties. The strength of supporting evidence was rated. The guidelines cover the diagnosis of bipolar disorder, clinical management, and strategies for the use of medicines in treatment of episodes, relapse prevention and stopping treatment.
White matter hyperintensities in late life depression: a systematic review.
BACKGROUND: White matter hyperintensities in MRI scans are age related but appear to be more prevalent in depressed patients. They may be more pronounced in late onset depression. This finding, if confirmed, would potentially illuminate the heterogeneity of depression in elderly subjects. METHODS: We conducted a systematic literature search of studies investigating white matter changes in late life depression, identifying 98 studies. The 30 remaining eligible studies were scrutinised for the presence and severity measures of periventricular and deep white matter changes in late life, late onset and, if available, early onset depression as well as in controls. Comparisons between groups were entered into random effects meta-analyses using odds ratios and Cohen's d, as appropriate. Correlations with potential confounders, such as age difference between groups, were explored. RESULTS: Late life depression and, to a greater extent, late onset depression in late life were characterised by more frequent and intense white matter abnormalities. In particular, the odds of having white matter changes were over 4 for late compared with early onset depression. Similarly, on severity scales, late onset depression had scores of 0.7-0.8 standard deviations above early onset patients. CONCLUSIONS: Significant differences between early and late onset depression suggest different aetiological mechanisms, in accordance with a theory of "cerebrovascular" depression of late onset. Greater duration of depressive symptoms, signs and treatment does not appear to have a measurable impact on white matter signal in MRI scans.
Left dorso-lateral repetitive transcranial magnetic stimulation affects cortical excitability and functional connectivity, but does not impair cognition in major depression.
PURPOSE: Transcranial magnetic stimulation (TMS) has been used for over a decade to investigate cortical function. More recently, it has been employed to treat conditions such as major depression. This study was designed to explore the effects of differential treatment parameters, such as stimulation frequency. In addition, the data were examined to determine whether a change in connectivity occurred following TMS. METHOD: Fifteen patients with major depression were entered into a combined imaging and treatment experiment with single photon emission computed tomography (SPECT) and repetitive transcranial magnetic stimulation (rTMS) over left dorso-lateral prefrontal cortex (DLPFC). Brain perfusion during a verbal fluency task was compared between pre- and poststimulation conditions. Patients were then treated with 80% of motor threshold for a total of 10 days, using 5000 stimuli at 5, 10 or 20 Hz. Tests of cortical excitability and neuropsychological tests were done throughout the trial. FINDINGS: Patients generally improved with treatment. There was no perceptible difference between stimulation frequencies, which may have reflected low study power. An increase in rostral anterior cingulate activation after the treatment day was associated with increased functional connectivity in the dorso-lateral frontal loop on the left and the limbic loop on both sides. No noticeable deterioration in neuropsychological function was observed. CONCLUSION: TMS at the stimulation frequencies used seems to be safe over a course of 5000 stimuli. It appears to have an activating effect in anterior limbic structures and increase functional connectivity in the neuroanatomical networks under the stimulation coil within an hour of stimulation.
Cerebral perfusion in chronic fatigue syndrome and depression.
BACKGROUND: Patients with chronic fatigue syndrome (CFS) and depressive illness share many, but not all, features. AIMS: To test the hypothesis that patients with CFS have abnormal cerebral perfusion, that differs from that in patients with depressive illness. METHOD: We recruited 30 patients with CFS who were not depressed, 12 depressed patients and 15 healthy volunteers. Regional cerebral perfusion at rest was assessed using region of interest (ROI) and voxel-based statistical parametric mapping (SPM) techniques. RESULTS: On SPM analysis there was increased perfusion in the right thalamus, pallidum and putamen in patients with CFS and in those with depressive illness. CFS patients also had increased perfusion in the left thalamus. Depressed patients differed from those with CFS in having relatively less perfusion of the left prefrontal cortex. The results were similar on ROI analysis. CONCLUSIONS: Abnormal cerebral perfusion patterns in CFS subjects who are not depressed are similar but not identical to those in patients with depressive illness. Thalamic overactivity may be a correlate of increased attention to activity in CFS and depression; reduced prefrontal perfusion in depression may be associated with the greater neuropsychological deficits in that disorder.
Executive function and uptake of 99mTc-exametazime shown by single photon emission tomography after oral idazoxan in probable Alzheimer-type dementia.
Preliminary reports suggest improved executive function in patients with lobar dementia after treatment with single doses of the alpha 2 adrenoceptor antagonist, idazoxan. The potential for use in probable Alzheimer-type dementia prompted the present study. Fifteen patients with probable Alzheimer-type dementia were examined twice with neuropsychological measures and 14 also with single photon emission tomography (SPET) after a single double blind oral administration of 40 mg idazoxan or placebo in a balanced cross-over design. Brain perfusion maps were spatially transformed into standard stereotactic space and compared pixel-by-pixel. A parametric analysis was used to examine the relationship between the drug effect, verbal fluency and brain perfusion. Two to 3 h after idazoxan, measures of reaction time, Stroop test, category fluency and anxiety were unchanged. Verbal fluency (letter) and spatial working memory were impaired and performance on the Tower of London test in a sub-set of patients showed a trend to impairment in the idazoxan condition. Idazoxan produced a modest relative activation in left thalamus and inferior occipital cortex: decreases occurred in inferior anterior cingulate and left insular cortex. There were significant correlations on both days between measures of fluency and brain perfusion in left lateral prefrontal cortex. The reduced performance with idazoxan was directly correlated with reduced perfusion in left lateral prefrontal cortex, supporting an important interaction between drug and task performance. The imaging component of the study therefore suggested that activation of frontal networks is necessary for performing fluency tasks in Alzheimer-type dementia. Brain networks involving prefrontal cortex are the locus for the primary cognitive effects of noradrenergic drugs. The direction of the effect of any dose of agonist or antagonist may depend critically upon the age and pathology of the experimental subjects and the relationship between performance, noradrenergic drive and task difficulty.
Single photon emission computed tomography in long-term survivors of adult brain tumours.
Sixteen patients with primary brain tumours were examined on average eight years after treatment with surgery or whole brain irradiation using standard clinical assessment, CT, a neuropsychological test battery, and single photon emission CT (SPECT) with 99mTc-exametazime. Seventeen lesions were discovered on inspection of SPECT images, 11 with x-ray CT. Quantitative assessment of tracer uptake compared with 16 matched healthy volunteers was consistent with the presence of lesions. Measurement of uptake in brain regions of the hemisphere not containing the primary tumour still showed significant reductions in patients. This may be due to remote direct effects of the tumour or, more likely, to the whole brain irradiation received. Psychometric performance on most tests was significantly impaired in the patient group and was correlated with abnormalities of tracer uptake to relevant brain regions.
Primary care management of patients who self-harm.
Self-harm is best defined as 'any act of self-poisoning or self-injury carried out by an individual irrespective of motivation'. With a 10.5% lifetime risk, self-reported self-harm is common in the community. Self-harm can occur at any age but is most common in young people. Prior self-harm is the key risk factor both for repeated self-harm and also for subsequent suicide. The presence of depressive symptoms predicts repeated self-harm, as does any history of psychiatric illness. Assessment of self-harm (actual or planned) should include: details of preplanning; final acts; the event itself; what happened afterwards; as well as broader psychosocial risk factors. Patients should be asked to reflect on the episode to consider whether they regret it, or whether they are likely to repeat it. Patients should be screened for depression, anxiety, psychosis and history of self-harm. Physical illness and substance misuse increase risk. Referral to secondary care community mental health teams should be considered for patients who present in primary care with a history of self-harm and a risk of repetition. Patients with continuing thoughts or serious intent of self-harm, where supportive or protective factors cannot be identified, may need urgent referral to secondary care. Prediction of further episodes of self-harm is difficult. Some clinicians may find the use of standardised rating scales, such as the SAD PERSONS scale, a useful way to identify patients who warrant referral and further assessment. The GP should provide long-term continuity of care, and maintain a holistic awareness of a patient's life events enabling discussion of the patient's emotional problems at an early stage with the aim of intervening before a crisis.
Identifying patients at risk of perinatal mood disorders.
Perinatal mental illness influences obstetric outcomes, mother-baby interactions and longer term emotional and cognitive development of the child. Psychiatric disorders have consistently been found to be one of the leading causes of maternal deaths, often through suicide. Postnatal depression and puerperal psychosis are two disorders most commonly associated with the perinatal period. The most efficient strategy to identify patients at risk relies on focussing on clinically vulnerable subgroups: enquiries about depressive symptoms should be made at the usual screening visits. Attention should be paid to any sign of poor self-care, avoidance of eye contact, overactivity or underactivity, or abnormalities in the rate of speech. Particular care should be taken to ask about suicidal ideation and thoughts of harming others, including the baby. One of the most important risk factors is a previous history of depression. The degree of risk is directly correlated with severity of past episodes. Both antenatal and postnatal depression are being increasingly recognised in men. Puerperal psychosis is rare (1 to 2 per 1,000). Sixty per cent of women with puerperal psychosis already have a diagnosis of bipolar disorder or schizoaffective disorder. Women with a personal history of postpartum psychosis or bipolar affective disorder should be considered as high risk for postpartum psychosis. All pregnant women who are identified as being at high risk should have a shared care plan for their late pregnancy and early postnatal psychiatric management. Women with current mood disorder of mild or moderate severity who have a first-degree relative with a history of bipolar disorder or postpartum psychosis should be referred for psychiatric assessment.
The influence of ApoE4 on clinical progression of dementia: a meta-analysis.
OBJECTIVE: ApoE4 is a risk factor for the development of Alzheimer's disease, and has a functional role suggesting its importance in the neuropathology of dementia. We present a meta-analysis to investigate whether ApoE4 also affects the clinical progression of dementia in terms of cognitive decline or mortality. METHODS: We searched Medline, Embase and PsychINFO from 1990 until April 2009, for case control or cohort studies which investigated the effect of ApoE4 on progression of dementia. We identified 427 studies; 17 were suitable for inclusion. In total, there were 1733 participants with dementia at baseline, of whom 975 were heterozygous or homozygous for ApoE4. RESULTS: There was no significant difference in cognitive decline (random-model effect size = 0.02; 95% C.-I.: -0.09 to 0.14; p = 0.67) or mortality (random-model pooled odds ratio = 0.74; 95% C.-I.: 0.36 to 1.53; p = 0.41) based on the presence of ApoE4. There was no significant heterogeneity between studies using cognitive decline as an outcome. In meta-regressions of cognitive decline, duration of symptoms, age, gender and frequency of participants with ApoE4 in the samples did not contribute to outcome. CONCLUSION: Different ApoE alleles do not modify the speed of clinical progression of dementia in a way that would be detectable in a sample of 1700 patients.
A hierarchy of happiness? Mokken scaling analysis of the Oxford Happiness Inventory
The items of the Oxford Happiness Inventory (OHI), a self-report assessment of happiness, are subjected to an analysis for hierarchy among its items. By using Mokken scaling analyses we can assess whether items can reliably be ordered between persons as severity indicators on a latent trait; in this case, a latent trait of Happiness. OHI item-level data from 1024 participants were entered into the Mokken Scaling Procedure (MSP) seeking reliable scales with H > 0.30. 12 OHI items formed a reliable and statistically significant hierarchy. However, the MSP values indicate a 'weak' scale. The 'most difficult' (happiest) item on the scale is 'feeling energetic' and the 'least difficult' (least happy) is 'I have fun'. Items in the scale are consistent with what is already known about both happiness and low mood. The reduction in the OHI's items from 29 to 12 in the Mokken scale may have utility making it more accessible to participants as well as identifying items with reliably different levels of 'difficulty'. © 2010 Elsevier Ltd. All rights reserved.
Managing bipolar disorder in primary care.
Bipolar disorder is relatively common, at least twice as common as schizophrenia, and eminently treatable. It is also perfectly suited to the well established outpatient model practised in general practice and psychiatry. All GP practices should include people with a diagnosis of bipolar disorder on their case register of people with severe mental illness. It is not possible to exclude a bipolar diagnosis categorically if there are only symptoms of depression. Most patients will have had a (hypo)manic episode by their 30s. The lifetime prevalence of bipolar affective disorder proper is 1%, with a further 1.2% presenting with milder hypomanic symptoms (so-called bipolar II disorder). Relaxing diagnostic symptom criteria increases the frequency of depressed patients who develop symptoms of mania for any length of time to 50%. The lifetime course of the illness tends to be dominated by depressive episodes: half the time is estimated to be spent in the euthymic (well) state, 12% in a manic state and 38% in a depressed state. Any depressed patient should be asked about periods in the past when (s)he has been elated in mood, found it unnecessary to sleep, talked a lot, spent excessive amounts of money etc. Treatment for bipolar disorder has to be divided into: treatment of mania, treatment of bipolar depression and prophylaxis of mood swings in either direction. Antidepressant treatments are unlikely to help manic symptoms, at worst they can precipitate or aggravate them. Antimanic treatments are unlikely to help symptoms of depression but an exception to this rule would be a genuine mood stabiliser, such as lithium. Patients with bipolar disorder should have an annual physical health review. This will include monitoring for weight gain, lipid levels, plasma glucose levels, smoking status and alcohol use, as well as blood pressure.