Depression, intellectual impairment, and Parkinson disease

Effects of hormone replacement therapy and aging on cognition: evidence for executive dysfunction

The present study was designed to explore whether the frontal lobe hypothesis of cognitive aging may be extended to describe the cognitive effects associated with estrogen use in postmenopausal women. Postmenopausal estrogen-only users, estrogen + progesterone users, and non-users (60-80 years old), as well as young, regularly cycling women (18-30 years old) completed an item and source memory task. Since source memory is thought to rely more on executive processes than item memory, we hypothesized that aging and estrogen effects would be greater for source memory than for item memory. Neuropsychological tests explored whether the effects of aging and estrogen use were revealed on other tests of frontal lobe function. Results from the experimental task revealed greater aging and estrogen effects for source memory than for item memory, and neuropsychological results revealed aging and estrogen effects on a subset of tests of executive function. Women on estrogen + progesterone therapy did not outperform non-users, suggesting that the addition of progesterone to hormone therapy may mitigate the benefits induced by estrogen use alone. Overall, findings support the hypothesis that estrogen use may temper age-related cognitive decline by helping to maintain functions subserved by the frontal lobes.

Use it or lose it? SES mitigates age-related decline in a recency/recognition task

An important goal of aging research is to determine factors leading to individual differences that might compensate for some of the deleterious effects of aging on cognition. To determine whether socio-economic status (SES) plays a role in mitigating age-related decrements in the recollection of contextual details, we categorized older participants into low- and high-SES groups. Event-related potentials (ERPs) and behavioral data were recorded in a picture memory task involving recency and recognition judgments. Young, old-low and old-high SES groups did not differ in recognition performance. However, on recency judgments, old-low subjects performed at chance, whereas old-high subjects did not differ significantly from young adults. Consistent with their preserved recency performance, a long-duration frontal negativity was significantly larger for recency compared to recognition trials in the ERPs of the old-high SES group only. These data suggest that older adults with higher SES levels can use strategies to compensate for the adverse effects of aging in complex source memory tasks by recruiting additional neural resources apparently not required by the young.

Frontal functions in depressed and nondepressed Parkinson's disease patients: impact of severity stages

Severity of Parkinson's disease (PD) and frontal impairment are positively correlated. Testing frontal functions in depressed/nondepressed PD patients with different severity stages may reveal whether depression leads to this impairment. We aimed to relate severity of PD to frontal functional impairment and to test if negative stimuli/depressive symptoms interfered with frontal tasks. The Stroop test and the Emotional Stroop test were performed by 46 PD patients, 18 of whom were depressed. The Hoehn and Yahr scale assessed severity of the disease. We calculated the difference in seconds for each Stroop card and the interference index (C/D) between depressed and nondepressed patients sharing the same severity of disease. The differences among the groups (depressed and nondepressed) according to the severity of the disease (mild and moderate) were compared using the Mann-Whitney test. The depressed patients had a poorer performance on the test than the nondepressed PD patients, although the difference was not statistically significant. In conclusion, there is a clinically relevant but not statistically significant difference on the performance of frontal tasks between depressed and nondepressed PD patients. Neither depression nor the severity of the disease were determinant to the poorer performance on the Stroop and the Emotional Stroop tests.

What is the evidence for a premorbid parkinsonian personality: a systematic review

Rigid and introverted personality type has been suggested as possibly associated with risk of Parkinson's disease (PD). However, to be a risk, the measurement of personality must precede the onset of PD, more than simply reported as personality in PD cases. Several reviews have been published examining the literature base for this suggestion; however, the issue of "premorbid" personality measurement was not emphasized. MEDLINE, EMBASE, and PSYCHINFO databases were searched for existing systematic reviews or meta-analyses, and none were found that fulfilled this criterion. The databases were searched systematically for primary research articles. Articles without robust methodology were excluded based on published quality scoring criteria. No articles met all selection criteria. Four articles met most selection criteria and three of them reported significant differences in personality features said to be present before PD onset and between PD cases and controls. PD cases were more introverted, cautious, socially alert, and tense than controls. Although the instruments used to characterize personality varied widely across studies, the general descriptions of PD patients included nervous, cautious, rigid, and conventional. There do appear to be parkinsonian characteristics, but these studies were all retrospective. To confirm that personality traits precede PD onset and are a risk for this condition, prospective research is required. Even then, the term "premorbid" is difficult to define due to the unknown latent period before onset of PD. Additional research would involve correlating personality characteristics to activities or changes in the brain.

Depression symptoms in movement disorders: Comparing Parkinson's disease, dystonia, and essential tremor

Depression is common in Parkinson's disease (PD) and affects 30 to 50% of all patients. In contrast to the wealth of research on depression in PD, little is known about the occurrence of depression in other movement disorders. The primary objective of the current study was to determine whether the high prevalence of depression symptoms seen in PD is also found in other movement disorders, by directly comparing rates of specific depression symptoms and depression severity across PD, dystonia, and essential tremor (ET). Three hundred and fifty-four patients with PD, 83 patients with dystonia, and 53 patients with ET completed the Beck Depression Inventory (BDI). We found no significant between-groups differences for depression severity, frequency, or endorsement of specific depression symptoms. Forty-eight percent of PD patients, 37.3% of dystonia patients, and 34% of ET patients were found to be at least mildly depressed (BDI score of 10 or higher). The most commonly endorsed symptoms were fatigability, difficulty with work, anhedonia, and sleep disturbance. Clinicians should be aware that depression is a frequent problem in dystonia and ET, in addition to PD, and inquire about depression symptoms in these patients so that they can be appropriately treated.

Depressivität und Depression bei der Parkinson-Erkrankung

Zusammenfassung: Ein erheblicher Anteil an Patienten mit einer idiopathischen Parkinson-Erkrankung (PD) entwickelt im Verlauf eine sekundäre Depression. Die Prävalenzraten schwanken erheblich, da die Diagnosestellung aufgrund von Symptomüberschneidungen zwischen neurologischer Grunderkrankung und Major Depression (MD) erschwert ist. Dies führt zu Problemen bei der therapeutischen Indikationsstellung sowie zu einer eingeschränkten Interpretierbarkeit neuropsychologischer und neurophysiologischer Studien. Ein weiterer Aspekt bezieht sich auf Gemeinsamkeiten und Unterschiede zwischen sekundärer und primärer Depression. Entgegen dem klinischen Eindruck einer PD-spezifischen Depression erbrachten psychometrische Verfahren zur Depressionsdiagnostik diesbezüglich bisher nur unbefriedigende Ergebnisse. Ziele dieses Überblicksartikels: 1. Charakterisierung depressiver Syndrome bei der PD, 2. Überblick über den Forschungsstand zur Neuropathologie und Neuropsychologie, 3. Gegenüberstellung klinisch- und/oder neuropsychologischer Gemeinsamkeiten/Unterschiede zwischen sekundärer und primärer MD und 4. Konsequenzen für Forschung und Differenzialdiagnostik.

Testing the limits of cognitive plasticity in older adults: application to attentional control

Laboratory based training studies suggest that older adults can benefit from training in tasks that tap control aspects of attention. This was further explored in the present study in which older and younger adults completed an adaptive and individualized dual-task training program. The testing-the-limits approach was used [Lindenberger, U., & Baltes, P. B. (1995). Testing-the-limits and experimental simulation: Two methods to explicate the role of learning in development. Human Development, 38, 349-360.] in order to gain insight into how attentional control can be improved in older adults. Results indicated substantial improvement in overlapping task performance in both younger and older participants suggesting the availability of cognitive plasticity in both age groups. Improvement was equivalent among age groups in response speed and performance variability but larger in response accuracy for older adults. The results suggest that time-sharing skills can be substantially improved in older adults.

Cognitive, Affective, and Psychiatric Features of Parkinson's Disease

Nonmotor symptoms, including cognitive deterioration and dementia, depression and apathy, and psychosis, are common in Parkinson's disease. Their presence is associated with a tremendous burden for the patient and family members. This article reviews the pathophysiololgy, risks, impact, major features, diagnosis, and treatment of these symptoms in Parkinson's disease.

Depression predicts the pattern of cognitive impairment in early Parkinson's disease

OBJECTIVE

To estimate the pattern of cognitive impairment in early Parkinson's disease (PD) associated with depression. Also, the prediction of potentially relevant demographic/clinical factors in early PD on cognitive functioning was tested.

METHOD

The study comprised 80 consecutive early PD patients (16 with major depression (PDMD), 10 PD patients with dysthimic disorder (PDDD), and 54 nondepressed PD patients (PDND)). Thirty_seven healthy subjects matched for age, gender and education were also included in the study. The cognitive evaluation included the comprehensive classical neuropsychological battery and the Cambridge Neuropsychological Test Automated Battery (CANTAB).

RESULTS

The two different patterns of cognitive impairment in early PD patients were obtained even when the confounding influences of general cognitive abilities and motor slowness were taken in account. One pattern was common to all PD patients either they were depressed or not, and it is conceived etiologically as dysexecutive. The PDDD group presented only the quantitative increment of the common deficit observed in PD. The second pattern was present in PDMD patients, involved episodic/working memory and language deficits alongside with background executive impairment. Depression was extensively associated with the cognitive dysfunction in early PD, whereas severity of the disease, age at onset and treatment were less favorable as predictors.

CONCLUSIONS

This study provides evidence that the pattern of cognitive impairment in early PD may be predicted by depression severity. Therefore, the recognition and treatment of depressive disorder in early PD is important.

Phenomenology and management of cognitive and behavioral disorders in Parkinson's disease. Rise and logic of dementia in Parkinson's disease

An overview of studies on the issue of dementia in Parkinson's disease shows that, over time, there has been an evolution in the perception of the magnitude of the problem and of its nature. Dementia seems today to be part of the disease. This change in the understanding of the disease can be accounted for by various methodological problems and by difficulties, on one hand, in the definition of dementia and its differentiation from other conditions, and, on the other hand, in the diagnosis of the disease itself in individual cases. Optimal therapeutic strategies are also examined, either based on cholinesterase inhibitors or antiparkinsonian drugs and symptomatic measures.

Aging effects on the ERP correlates of involuntary attentional capture in speech sound analysis

In an auditory oddball paradigm, 16 old and 16 young adults were asked to ignore binaurally presented disyllabic speech sounds and to watch a silent movie while event-related potentials (ERPs) were recorded. Four types of phonetic deviants occurred on, respectively: (1) the Stressed-First syllable, (2) the Unstressed-First syllable, (3) the Stressed-Second syllable and (4) the Unstressed-Second syllable. The nature of the phonetic change was the same across the four deviants. A P3a was seen only for deviant 3 in the elderly while observed for deviants 1 and 3 in the young. The mismatch negativities (MMNs) to deviants 1 and 2 were reduced compared with those to the other two deviants in both age groups. It is concluded that the ability to use salient prosody to involuntarily capture attention for speech sounds is preserved in normal aging. The lack of P3a response to deviant 1 in the elderly may result from the combined effects of backward masking and age-related temporal encoding inefficiency as indicated by reduced MMNs for the elderly.

The quality of care delivered to Parkinson's disease patients in the U.S. Pacific Northwest Veterans Health System

Background

Parkinson's disease (PD) is the second most common chronic neurological disorder of the elderly. Despite the fact that a comprehensive review of general health care in the United States showed that the quality of care delivered to patients usually falls below professional standards, there is limited data on the quality of care for patients with PD.

Methods

Using the administrative database, the Pacific Northwest Veterans Health Administration (VHA) Data Warehouse, a population of PD patients with encounters from 10/1/98-12/31/04 were identified. A random sample of 350 patient charts underwent further review for diagnostic evaluation. All patients whose records revealed a physician diagnosis of definite or possible Idiopathic Parkinson's (IPD) disease (n = 150) were included in a medical chart review to evaluate adherence to five evidence-based quality of care indicators.

Results

For those care indicators with good inter-rater reliability, 16.6% of care received by PD patients was adherent for annual depression screening, 23.4% of care was adherent for annual fall screening and, 67.3% of care was adherent for management of urinary incontinence. Patients receiving specialty care were more likely to be adherent with fall screening than those not receiving specialty care OR = 2.3, 95%CI = 1.2–4.2, but less likely to be adherent with management of urinary incontinence, OR = 0.3, 95%CI = 0.1–0.8. Patients receiving care outside the VA system were more likely to be adherent with depression screening OR = 2.4, 95%CI = >1.0–5.5 and fall screening OR = 2.2, 95%CI = 1.1–4.4.

Conclusion

We found very low rates of adherence for annual screening for depression and falls for PD patients but reasonable adherence rates for management of urinary incontinence. Interestingly, receiving concurrent specialty care did not necessarily result in higher adherence for all care indicators suggesting some coordination and role responsibility confusion. The increased adherence in PD patients receiving care outside the VA system suggests that patients with outside care may demand better care within the VA system.

Recognizing depression in patients with Parkinson’s disease: accuracy and specificity of two depression rating scale

This study aimed to find cut-off scores for the Montgomery-Asberg rating scale (MADRS) and the Beck depression inventory (BDI) that can relate to specific clinical diagnoses of depression in Parkinson´s disease (PD). Mild and moderate PD patients (n=46) were evaluated for depression according to the DSM IV criteria. All patients were assessed with the MADRS and the BDI. A "receiver operating characteristics" (ROC) curve was obtained and the sensibility, specificity, positive and the negative predictive values were calculated for different cut-off scores of the MADRS and the BDI. The Kappa statistic was calculated for different cut-off scores to assess the agreement between the clinical judgment and both scales. Depression was present in 18 patients. MADRS cut-off scores of 6 and 10 showed Kappa 0.5 and 0.56, respectively. Specificity of cut-off score of 6 was 78.6% and of cut-off score of 10 was 96.4%. Kappa agreement of BDI cut-off scores of 10 and 18 were 0.36 and 0.62, respectively. Specificity was 60.7% for 10 and 92.9% for 18. Both rating scales show similar accuracy within the ROC curves (84.3% for MADRS and 79.7% for BDI). The MADRS and the BDI show a good accuracy and correlation to the clinical diagnosis when a cut-off score of 10 is used to MADRS and a cut-off score of 18 is used to BDI to recognize depression in mild to moderate PD patients. This may help clinicians to recognize depression in PD.

Imaging in Parkinson's disease: the role of monoamines in behavior

Positron emission tomography (PET) and single photon emission computed tomography (SPECT) can measure striatal dopamine (DA) terminal function in vivo as reflected by DA storage capacity and transporter binding. In Parkinson's disease (PD) posterior dorsal putamen DA terminals are initially targeted, the anterior putamen and head of caudate subsequently becoming affected. In contrast, dopaminergic function in pallidal, amygdala, and cingulate regions is upregulated in early PD and only later becomes reduced. Rigidity and bradykinesia in PD have been shown to correlate with loss of putamen dopaminergic function, whereas performance on executive and working memory tasks correlates with integrity of caudate dopaminergic terminals. 11C-RTI32 PET, a marker of noradrenergic and dopaminergic transporter binding, can be used to assess noradrenergic along with dopaminergic terminal function. Serotonergic transporter binding can be assessed with 11C-DASB PET and 123I-beta CIT SPECT, whereas HT1A binding can be measured with 11C-WAY100635 PET. With these modalities, the relationship between mood, noradrenergic and serotonergic function can be examined in PD. The functional effects of focal DA replacement on DA storage capacity and patterns of brain activation via implantation of fetal midbrain cells or glial derived neurotrophic factor (GDNF) infusion into putamen of PD patients has been examined with PET. Both approaches lead to consistently increased levels of putamen 18F-dopa uptake, and cell implantation can restore levels of frontal activation. Clinical outcome, however, has proved to be variable and off-medication dyskinesias are an unwanted side effect in transplanted cases. Dopamine release after pharmacological challenges or during behavioral tasks can be assessed indirectly by studying changes in receptor availability to PET radioligands. Stereotyped sequential movements are associated with striatal DA release, and this increases with more complex behaviors and the presence of financial incentives, which also increase frontal DA levels. Parkinson patients release less putamen DA than healthy control subjects during stereotyped finger movements. Interestingly, those PD patients who develop a dopa dependency syndrome, craving their medication, generate significantly greater levels of ventral striatal DA compared with similarly disabled patients without such a psychological dependency. In the future, functional imaging is likely to throw light on the roles of peptide transmission in regulating mood and behavior as non-peptide analogue ligands become available. Novel markers of amyloid plaque load will also help clarify the etiology of dementia in PD.

Reduced Suppression or Labile Memory? Mechanisms of Inefficient Filtering of Irrelevant Information in Older Adults

Cognitive aging theories emphasize the decrease in efficiency of inhibitory processes and attention control in normal aging, which, in turn, may result in reduction of working memory function. Accordingly, some of these age-related changes may be due to faster sensory memory decay or to inefficient filtering of irrelevant sensory information (sensory gating). Here, event-related brain potentials and the event-related optical signal were recorded in younger and older adults passively listening to tone trains. To determine whether age differentially affects decay of sensory memory templates over short intervals, trains were separated by delays of either 1 or 5 sec. To determine whether age affects the suppression of responses to unattended repeated stimuli, we evaluated the brain activity elicited by successive train stimuli. Some trains started with a shorter-duration stimulus (deviant trains). Results showed that both electrical and optical responses to tones were more persistent with repeated stimulation in older adults than in younger adults, whereas the effects of delay were similar in the two groups. A mismatch negativity (MMN) was elicited by the first stimulus in deviant trains. This MMN was larger for 1- than 5-sec delay, but did not differ across groups. These data suggest that age-related changes in sensory processing are likely due to inefficient filtering of repeated information, rather than to faster sensory memory decay. This inefficient filtering may be due to, or interact with, reduced attention control. Furthermore, it may increase the noise levels in the information processing system and thus contribute to problems with working memory and speed of processing.

A systematic review of depression and mental illness preceding Parkinson's disease

Depression has been reported in several studies to be more common in Parkinson's disease (PD) patients than in the general population, and there may be overlap in the pathophysiology of the two conditions. Anxiety and other mental disorders have also been examined for possible association with PD because of their effects on the brain. MEDLINE, EMBASE and PSYCHINFO databases were searched systematically for existing systematic reviews or meta-analyses and primary research articles. Past studies and reviews have focused on co-morbidity of depression or mental disorders and PD, but as yet there have been no systematic reviews of the evidence that these conditions precede PD. Articles without robust methodology were excluded by specified criteria, based on published quality scoring criteria. Three cohort studies, one nested case-control study, and 10 case-control studies are included in the current systematic review. Premorbid depression was significantly more common in PD patients than in those without a diagnosis of PD in five of six case-control studies and three cohort studies. Premorbid anxiety may also be associated with PD although the evidence was not as strong. A few studies have looked at dementia as a co-morbid or sequel, but never as a predictor of PD.

Factors associated with depression in Parkinson's disease: a cross-sectional study in a Polish population

OBJECTIVE

The aim of this study was to assess the prevalence and factors influencing depression in PD patients in a cross-sectional outpatient clinic - based Polish patients sample.

MATERIALS AND METHODS

One hundred consecutive PD patients were included in this study; 35 of them fulfilled DSM-IV criteria for Major Depression and its severity was assessed with Montgomery-Asberg Depression Rating Scale (MADRS). A structured interview and a neurological examination, including Hoehn and Yahr scale (H-Y), Schwab-England disability scale, II, III, IV parts of Unified Parkinson's Disease Rating Scale (UPDRS), and Mini-Mental State Examination (MMSE) were performed. The parameters obtained were analysed between the depressed and non-depressed PD patients.

RESULTS

The prevalence of depression in PD in Polish population was established at the level of 35%. PD patients with depression scored significantly higher in all UPDRS scales (except for the subscale of clinical fluctuation) and in H-Y scale. PD with depression was also associated with longer PD duration, higher doses of L-dopa equivalents, patients' age, general impairment of daily living in Schwab and England disability scale, lower MMSE and higher clinical fluctuations. However, those six differences were insignificant.

CONCLUSIONS

Depression prevalence rate among PD patients in Polish population is slightly lower than in most of other published studies. This may result from strict selection criteria, use of specific outcome measures and restricted criteria for depression that were applied.

Marker for a preclinical diagnosis of Parkinson's disease as a basis for neuroprotection

Neuroprotective therapy is a pivotal aim in the treatment of the relentlessly progressive disorder Parkinson's disease. However, more than 60% of the dopaminergic neurons of the substantia nigra have already degenerated, when the diagnosis may be established. At this "advanced stage" neuroprotective strategies will - if at all - only have limited effect. It is, therefore, essential to establish markers to identify subjects at risk before motor manifestation. A number of such "premotor" signs have been discovered and investigated lately. Such signs include a genetic vulnerability and hyperechogenicity of the substantia nigra as well as premotor symptoms like olfactory and autonomic dysfunction, depression, REM sleep behaviour disorder, visual and neuropsychological impairment. Moreover, first signs of affection of the substantia nigra like PET and SPECT abnormalities and slight motor signs can be included, as they may be detected before a definite diagnosis can be made. Although most of these signs and symptoms are unspecific if singularly evaluated a combination of these features may indeed be valuable to detect a subgroup of the population at risk for PD. However, future studies are necessary to establish the predictive value of these "markers" singularly and in combination.

Effect of repetitive TMS and fluoxetine on cognitive function in patients with Parkinson's disease and concurrent depression

Previous studies show that cognitive functions are more impaired in patients with Parkinson's disease (PD) and depression than in nondepressed PD patients. We compared the cognitive effects of two types of antidepressant treatments in PD patients: fluoxetine (20 mg/day) versus repetitive transcranial magnetic stimulation (rTMS, 15 Hz, 110% above motor threshold, 10 daily sessions) of the left dorsolateral prefrontal cortex. Twenty-five patients with PD and depression were randomly assigned either to Group 1 (active rTMS and placebo medication) or to Group 2 (sham rTMS and fluoxetine). A neuropsychological battery was assessed by a rater blind to treatment arm at baseline and 2 and 8 weeks after treatment. Patients in both groups had a significant improvement of Stroop (colored words and interference card) and Hooper and Wisconsin (perseverative errors) test performances after both treatments. Furthermore, there were no adverse effects after either rTMS or fluoxetine in any neuropsychological test of the cognitive test battery. The results show that rTMS could improve some aspects of cognition in PD patients similar to that of fluoxetine. The mechanisms for this cognitive improvement are unclear, but it is in the context of mood improvement.

Factors affecting the quality of life of patients with idiopathic Parkinson's disease-a cross-sectional study in an outpatient clinic attendees

PURPOSE

To determine the factors associated with poor quality of life (QoL) in patients with idiopathic Parkinson's disease (PD) in a clinic-based sample.

SCOPE

One hundred patients were included in this study. To assess the quality of life the Parkinson's Disease Questionnaire (PDQ-39) was used. A structured questionnaire interview and a complete neurological examination, including the Hoehn and Yahr scale (H-Y), the Schwab and England disability scale, II, III, IV parts of the unified Parkinson's disease rating scale (UPDRS part II, III, IV), Montgomery-Asberg depression rating scale (MADRS) and the Mini-Mental state examination (MMSE) were performed.

RESULTS AND CONCLUSIONS

The most important predictive factor was MADRS score, followed by clinical fluctuations as measured by UPDRS part IVB and the H-Y stage of disease, which account for 79% of the variance of QoL scores. Therefore, recognition of depression should become an important part of treatment of PD.

On why the elderly have normal semantic retrieval but deficient episodic encoding: a study of left inferior frontal ERP activity

Age-related left inferior prefrontal cortex (LIPFC) blood flow reductions during semantic retrieval are associated with reduced subsequent episodic recognition memory performance but are inconsistent with age-invariant semantic retrieval performance. Therefore, we compared brain activity in young and elderly persons during low- and high-selection versions of a semantic task using ERPs recorded at 62 scalp locations. In an early interval (400-800 ms), both age groups showed more negativity over left inferior frontal scalp while performing the high- compared to the low-selection task. This early semantic selection-related negativity was associated with age-equivalent accuracy and reaction time on the semantic tasks. Further, in the early time interval, the ERPs of the young were more negative than those of the elderly. In addition, only the young showed a late selection-related negativity (1,200--1,400 ms). These age-related differences in left frontal ERP activity were associated with significant decrements in subsequent recognition for the elderly. Moreover, additional analyses revealed that larger amounts of negativity over left inferior frontal scalp locations during semantic retrieval were correlated with enhanced subsequent episodic recognition in both groups. In sum, the data suggest that (1) semantic retrieval and episodic encoding processes overlap temporally in similar brain regions, most likely including the LIPFC, and (2) the failure to recruit these regions in the service of episodic encoding underlies the age-related deficit in episodic memory.

Delusions and hallucinations are associated with worse outcome in Alzheimer disease

BACKGROUND

Delusions and hallucinations are common in Alzheimer disease (AD) and there are conflicting reports regarding their ability to predict cognitive decline, functional decline, and institutionalization. According to all previous literature, they are not associated with mortality.

OBJECTIVE

To examine whether the presence of delusions or hallucinations has predictive value for important outcomes in AD.

DESIGN, SETTING, AND PARTICIPANTS

A total of 456 patients with AD at early stages (mean Folstein Mini-Mental State Examination [MMSE] score of 21 of 30 at entry) were recruited and followed up semiannually for up to 14 years (mean, 4.5 years) in 5 university-based AD centers in the United States and Europe. Using the Columbia University Scale for Psychopathology in AD (administered every 6 months, for a total of 3266 visit-assessments, average of 7.2 per patient), the presence of delusions and hallucinations was extracted and examined as time-dependent predictors in Cox models. The models controlled for cohort effect, recruitment center, informant status, sex, age, education, a comorbidity index, baseline cognitive and baseline functional performance, behavioral symptoms, and use of neuroleptics and cholinesterase inhibitors.

MAIN OUTCOME MEASURES

Cognitive (Columbia MMSE score of < or =20/57 [approximate Folstein MMSE score of < or =10/30]), functional (Blessed Dementia Rating Scale [parts I and II] score of > or =10), institutionalization equivalent index, and death.

RESULTS

During the full course of follow-up, 38% of patients reached the cognitive, 41% the functional, 54% the institutionalization, and 49% the mortality end point. Delusions were noted for 34% of patients at baseline and 70% at any evaluation. Their presence was associated with increased risk for cognitive (risk ratio [RR], 1.50; 95% confidence interval [CI], 1.07-2.08) and functional decline (RR, 1.41; 95% CI, 1.02-1.94). Hallucinations were present in 7% of patients at initial visit and in 33% at any visit. Their presence was associated with increased risk for cognitive decline (RR, 1.62; 95% CI, 1.06-2.47), functional decline (RR, 2.25; 95% CI, 1.54-2.27), institutionalization (RR, 1.60; 95% CI, 1.13-2.28), and death (RR, 1.49; 95% CI, 1.03-2.14).

CONCLUSIONS

Delusions and hallucinations are very common in AD and predict cognitive and functional decline. Presence of hallucinations is also associated with institutionalization and mortality.

The effect of depression on motor function and disease severity of Parkinson's disease

OBJECTIVES

Approximately 40% of patients with Parkinson's disease (PD) experience symptoms of depression. Our aim was to evaluate the effect of depression on disease severity, motor function and other phenotypic characteristics of PD.

PATIENTS AND METHODS

We studied 32 PD patients with major depression (PD-D) according to the DSM-IV criteria and 32 PD patients with no depression (PD-C) matched for gender, age of onset and duration.

RESULTS

Major depression in PD patients was associated with increased disease severity, poorer motor function and worse performance in the activities of daily living as measured by UPDRS scores. Furthermore, there was an association of depression with the severity of bradykinesia and axial rigidity.

CONCLUSIONS

Depression in PD can have a profound negative impact on a patient's sense of wellbeing and motor functioning. Therefore, PD patients should be routinely and carefully screened for the presence of depression and appropriate management should be considered. Larger studies on the subject are warranted.

Mood disorders in the medically ill: scientific review and recommendations

OBJECTIVE

The purpose of this review is to assess the relationship between mood disorders and development, course, and associated morbidity and mortality of selected medical illnesses, review evidence for treatment, and determine needs in clinical practice and research.

DATA SOURCES

Data were culled from the 2002 Depression and Bipolar Support Alliance Conference proceedings and a literature review addressing prevalence, risk factors, diagnosis, and treatment. This review also considered the experience of primary and specialty care providers, policy analysts, and patient advocates. The review and recommendations reflect the expert opinion of the authors.

STUDY SELECTION/DATA EXTRACTION

Reviews of epidemiology and mechanistic studies were included, as were open-label and randomized, controlled trials on treatment of depression in patients with medical comorbidities. Data on study design, population, and results were extracted for review of evidence that includes tables of prevalence and pharmacological treatment. The effect of depression and bipolar disorder on selected medical comorbidities was assessed, and recommendations for practice, research, and policy were developed.

CONCLUSIONS

A growing body of evidence suggests that biological mechanisms underlie a bidirectional link between mood disorders and many medical illnesses. In addition, there is evidence to suggest that mood disorders affect the course of medical illnesses. Further prospective studies are warranted.

Motor signs during the course of Alzheimer disease

BACKGROUND

Motor signs (MOSIs) are common in Alzheimer disease (AD) and may be associated with rates of cognitive decline, mortality, and cost of care.

OBJECTIVE

To describe the progression and identify predictors of individual MOSIs in AD.

METHODS

A cohort of 474 patients with AD at early stages was followed semiannually for up to 13.1 years (mean 3.6 years) in five centers in Europe and the United States. MOSIs were rated using a standardized portion of the Unified Parkinson's Disease Rating Scale. Overall, 3,030 visits/assessments of MOSIs (average 6.4/patient) were performed. Prevalence and incidence rates were calculated, and cumulative risk graphs were plotted for individual non-drug-induced MOSI domains. Rates of change over time taking into account potential covariates were also estimated. With use of each MOSI domain as outcome in Cox models, predictors of MOSI incidence were identified.

RESULTS

At least one MOSI was detected in 13% of patients at first examination and in 36% for the last evaluation. Total MOSI score increased at an annual rate of 3% of total possible score. Rates of annual change for speech/facial expression (4%), rigidity (2.45%), posture/gait (3.9%), and bradykinesia (3.75%) were of similar magnitude, and their occurrence increased from first (3 to 6%) to last (22 to 29%) evaluation. Tremor was less frequent throughout the course of the disease (4% at first and 7% at last evaluation) and worsened less (0.75% increase/year).

CONCLUSIONS

Most motor signs occur frequently and progress rapidly in Alzheimer disease. Tremor is an exception in that it occurs less frequently and advances at slower rates.

Depression in Parkinson's disease is related to a genetic polymorphism of the cannabinoid receptor gene (CNR1)

Depression is a common symptom in Parkinson's disease (PD) and it is present in up to 40% of the patients. The cause of depression in PD is thought to be related to disturbance of monoamine neurotransmission. The endogenous cannabinoid system mediates different brain processes that play a role in the control of behaviour and emotions. Cannabinoid function may be altered in neuropsychiatry diseases, directly or through interactions with monoamine, GABA and glutamate systems. For this reason, we have investigated whether there is a genetic risk factor for depression in PD linked to the polymorphisms of CB1 receptor gene. Depression was more frequent in patients with PD than in controls with osteoarthritis. The presence of depression did not correlate with the stage of the disease but it was more frequent in patients with pure akinetic syndrome than in those with tremoric or mixed type PD. The CB1 receptor gene polymorphism (AAT)n is considered to modify the transcription of the gene and, therefore, it may have functional relevance. We analysed the length of the polymorphic triplet (AAT)n of the gene that encodes CB1 (CNR1) receptor in 89 subjects (48 PD patients and 41 controls). In patients with PD, the presence of two long alleles, with more than 16 repeated AAT trinucleotides in the CNR1 gene, was associated with a reduced prevalence of depression (Fisher's exact test: P=0.003). This association did not reach significant differences in the control group, but the number of control individuals with depression was too small to allow for statistical analysis. Since the alleles with long expansions may have functional impact in cannabinoid neurotransmission, our data suggest that the pharmacological manipulation of cannabinoid neurotransmission could open a new therapeutic approach for the treatment of depression in PD and possibly in other conditions.

Inter- and intraindividual variability in recognition memory: effects of aging and estrogen use

Traditionally, studies of cognitive aging have focused on comparing the average performance of younger and older adults, whereas variability around the mean has been attributed to task-irrelevant noise. The present study examined the hypothesis that variability in memory performance increases with age and that estrogen helps temper age-related increases in variability. Postmenopausal estrogen users, estrogen and progestin (est + prog) users, and nonusers, as well as younger women, completed 16 blocks of an item-source memory task. Older women showed greater variability than younger women on measures of dispersion and consistency. Estrogen users, but not est + prog users, performed more consistently than nonusers. Overall, age-related increases in variability differed with the type of variability measured, and estrogen use, but not est + prog use, appeared to reduce age-related increases in at least 1 form of variability.

Training effects on dual-task performance: Are there age-related differences in plasticity of attentional control?

A number of studies have suggested that attentional control skills required to perform 2 tasks concurrently become impaired with age (A. A. Hartley, 1992; J. M. McDowd & R. J. Shaw, 2000). A. A. Hartley (2001) recently observed that the age-related differences in dual-task performance were larger when the 2 tasks required similar motor responses. The present study examined the extent to which age-related deficits in dual-task performance or time sharing--in particular, dual-task performance of 2 discrimination tasks with similar motor requirements--can be moderated by training. The results indicate that, even when the 2 tasks required similar motor responses, both older and younger adults could learn to perform the tasks faster and more accurately. Moreover, the improvement in performance generalized to new task combinations involving new stimuli. Therefore, it appears that training can substantially improve dual-task processing skills in older adults.

ERP correlates of involuntary attention capture by prosodic salience in speech

This study addressed whether temporally salient (e.g., word onset) or prosodically salient (e.g., stressed syllables) information serves as a cue to capture attention in speech sound analysis. In an auditory oddball paradigm, 16 native English speakers were asked to ignore binaurally presented disyllabic speech sounds and watch a silent movie while ERPs were recorded. Four types of phonetic deviants were employed: a deviant syllable that was either stressed or unstressed and that occurred in either the first or second temporal position. The nature of the phonetic change (a change from a voiced consonant to its corresponding unvoiced consonant) was kept constant. MMNs were observed for all deviants. In contrast, the P3a was only seen when the deviance occurred on stressed syllables. The sensitivity of the P3a to the stress manipulation suggests that prosodic rather than temporal salience captures attention in unattended speech sounds.

Psychiatric aspects of Parkinson's disease--an update

In patients with Parkinson's disease (PD) disturbances of mental state constitute some of the most difficult treatment challenges of advanced disease, often limiting effective treatment of motor symptoms and leading to increased disability and poor quality of life. This article provides an update on the current knowledge of these complications and the use of old and new drugs in their management. Mental state alterations in PD include depression, anxiety, cognitive impairment, apathy, and treatment-related psychiatric symptoms. The latter range from vivid dreams and hallucinations to delusions, manic symptoms, hypersexuality, dopamine dysregulation syndrome and delirium. While some of these symptoms may be alleviated by anti-parkinsonian medication, especially if they are off-period related, treatment-related phenomena are usually exacerbated by increasing the number or dosage of antiparkinsonian drugs. Elimination of exacerbating factors and simplification of drug regimes are the first and most important steps in improvement of such symptoms. However, the advent of atypical antipsychotics such as clozapine has dramatically helped the management of treatment-related psychiatric complications in PD. In patients with dementia associated with PD cognitive functioning and behavioural problems appear to respond to cholinesterase inhibitors, such as rivastigmine or donepezil. Depression is a common problem in early as well as advanced PD, and selective serotonin reuptake inhibitors, reboxetine, and tricyclic antidepressants have been reported to be effective and well tolerated antidepressants. Randomised, controlled studies are required to assess the differential efficacy and tolerability of antidepressants in patients with PD, including the newer antidepressants with serotonergic and noradrenergic properties.

Effect of Psychiatric and Other Nonmotor Symptoms on Disability in Parkinson's Disease

OBJECTIVES

To examine the effect of depression and other nonmotor symptoms on functional ability in Parkinson's disease (PD).

DESIGN

A cross-sectional study of a convenience sample of PD patients receiving specialty care.

SETTING

The Parkinson's Disease Research, Education and Clinical Center at the Philadelphia Veterans Affairs Medical Center.

PARTICIPANTS

One hundred fourteen community-dwelling patients with idiopathic PD.

MEASUREMENTS

The Unified Parkinson's Disease Rating Scale (UPDRS); Hoehn and Yahr Stage; Mini-Mental State Examination; Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, depression module; probes for psychotic symptoms; Hamilton Depression Rating Scale; Geriatric Depression Scale-Short Form; Apathy Scale; and Epworth Sleepiness Scale. Disability was rated using the UPDRS activity of daily living (ADL) score and the Schwab and England ADL score. Multivariate analysis determined effect of depression and other nonmotor symptoms on disability.

RESULTS

The presence of psychosis, depressive disorder, increasing depression severity, age, duration of PD, cognitive impairment, apathy, sleepiness, motor impairment, and percentage of time with dyskinesias were related to greater disability in bivariate analyses. Entering these factors into two multiple regression analyses, only the increasing severity of depression and worsening cognition were associated with greater disability using the UPDRS ADL score, accounting for 37% of the variance in disability (P<.001). These two factors plus increasing severity of PD accounted for 54% of the variance in disability using the Schwab and England ADL score (P<.001).

CONCLUSION

Results support and extend previous findings that psychiatric and other nonmotor symptoms contribute significantly to disability in PD. Screening for nonmotor symptoms in PD is necessary to more fully explain functional limitations. Further study is required to determine whether identifying and treating these symptoms will improve function and quality of life.

Psychiatric comorbidity in a population of Parkinson's disease patients

Behavioural disturbances are frequently observed in Parkinson's disease (PD), including mood and anxiety disorders. The existence of a comorbidity between such psychiatric disorders in PD patients has been suggested only in a few studies. To assess the prevalence of mood and anxiety disturbances, and the rate of comorbidity of such disorders in PD. Secondary aim was to correlate the prevalence of psychiatric disorders in PD with age, sex, laterality of motor symptomatology, clinical features, severity of disease, age of onset and PD duration, and anti-parkinsonian therapy. Ninety consecutive PD outpatients, and 90 age- and sex-matched controls were included. All PD patients enrolled were non-fluctuating (21 de novo, 69 treated with levodopa or dopamine agonists). PD patients and controls with Mini Mental State Examination score <23 were excluded. Psychiatric diagnosis was performed by semistructured interview according with DSM-IV criteria and the severity of depressive and anxious symptoms was rated with clinical rating scales. Major depression was found in 21.1% PD patients vs. 3.3% controls (P < 0.01, chi-square analysis), dystimia in 18.8% PD patients vs. 4.4% controls (P < 0.05), panic disorders in 30% PD patients vs. 5.5% controls (P < 0.01). No difference in the prevalence of other anxiety disorders was observed between the two groups. The comorbidity of mood and anxiety disorders was found in 19.3% PD patients vs. 8.6% controls (P < 0.01). No correlation was reported between the prevalence of behavioural disturbances and any of the demographic, clinical or pharmacological data taken into account. Our findings might suggest the existence of a wide spectrum of psychiatric disorders in PD ranging from pure depressive disorders, comorbid depressive and anxiety disorders, and pure anxiety disorders, presumably linked to the same neurobiological substrate.

Nocturnal sleep disturbances and daytime dysfunction in patients with Parkinson's disease and in their caregivers

BACKGROUND

The role of aging, disease, medications, and mood disturbances in sleep disturbances (SD) in patients with Parkinson's disease (PD) is poorly understood, and the impact of SD on the quality of life of their caregivers (CG) largely undocumented.

OBJECTIVES

To evaluate the pattern and determinants of disturbed sleep in PD patients complaining of SD, and in their primary CG.

METHODS

A prospective evaluation of 40 non-demented patients with PD complaining of SD and 23 of their primary CG (all were spouses) was conducted using Pittsburgh Sleep Quality Index, Zung's self-rating depression and anxiety scales, Parkinson's Impact Scale (PIMS) (only for PD), and an additional sleep questionnaire.

RESULTS

Eighty-four percent of patients were 'poor sleepers' with global sleep scores (GLSc) > 5. Other abnormalities were: excessive daytime sleepiness-57.5%, excessive daytime fatigue-72.5%, depression-51.5%, anxiety-63.1%, and abnormal PIMS score-83.8%. There was no correlation between the degree of sleep dysfunction and the age, severity, duration of PD or its treatment. Several component sleep scores correlated with anxiety scores, PIMS score with depression, and, subjects with GLSc > or = 10 had higher mean anxiety index. Daytime dysfunction (97.5%) was mainly associated with reduced enthusiasm, rather than excessive sleepiness. Among CG, 40% had a GLSc > 5, 21% had depression, and 10.5% had anxiety. Their depression, anxiety and sleep scores correlated with those of their spouses.

CONCLUSIONS

PD patients with significant SD may represent a subset of patients with early, progressive degeneration of sleep centres, rather than an enhanced aging process. They are more susceptible mood disturbances, which correlate with the severity of sleep dysfunction. Sleep and mood disturbances also adversely affect the quality of life of spousal caregivers.

Aging and the Strategic Control of the Fixation Offset Effect

A study was conducted to examine potential age-related differences in the strategic control of exogenous and endogenous saccades within the context of the fixation offset effect (FOE; i.e., faster saccades when a fixation point is removed than when it is left on throughout a trial). Subjects were instructed to make rapid saccades either on the basis of a suddenly appearing peripheral visual stimulus (exogenous saccade) or in response to a tone (endogenous saccade). On half of the trials the fixation point was removed simultaneously with the occurrence of the cue stimulus. Subjects' preparatory set was varied by manipulating the proportion of saccades generated to a visual and auditory stimulus within a trial block. Young and old adults both produced FOEs, and the FOEs were strategically modulated by preparatory set. The data are discussed in terms of aging and oculomotor control.

Correlates of Generalized Anxiety and Panic Attacks in Dystonia and Parkinson Disease

OBJECTIVE

To determine prevalences of generalized anxiety, generalized anxiety disorder, panic attacks, and panic disorder in primary dystonia (n = 28) and Parkinson disease (n = 28) and to explore their clinical correlates.

BACKGROUND

We previously identified increases in Diagnostic and Statistical Manual of Mental Disorders, third edition generalized anxiety in dystonia and panic attacks in Parkinson disease.

METHOD

Structured Clinical Interview (SCID) ascertainment of Diagnostic and Statistical Manual of Mental Disorders, third edition, revised, disorders.

RESULTS

Generalized anxiety disorder was more common in dystonia while panic disorder was more common in Parkinson disease (P = 0.0018). Generalized anxiety developed more commonly after dystonia onset (i.e., secondary generalized anxiety) while panic attacks developed more commonly after Parkinson disease onset (P = 0.0132). Specific life prevalences were: generalized anxiety disorder, 7 subjects (25.0%) in dystonia versus 0 subjects (0.0%) in Parkinson disease; generalized anxiety, 11 (39.3%) versus 0 (0.0%); panic disorder, 2 (7.1%) versus 7 (25.0%); and panic attacks, 2 (7.1%) versus 9 (32.1%). Exploratory analysis in Parkinson disease indicated a relationship of panic disorder (P = 0.027) and secondary panic attacks (P = 0.0009) to motor block frequency. There were nonsignificant trends toward associations of secondary generalized anxiety with lower Mini Mental Status Examination scores (P = 0.058), and of secondary panic attacks with presence of a depressive disorder (P = 0.077). Depressive comorbidity rates are also presented.

CONCLUSIONS

These findings suggest relations of generalized anxiety with reduced pallidal inhibition of thalamofrontotemporal projections, and panic attacks with locus coeruleus dysfunction.

Depression in Parkinson's disease: clinical correlates and outcome

Depression has been shown to be more common in Parkinson's disease (PD) than in other chronic and disabling disorders. Neurochemical and functional disturbances are important etiopathogenic factors. The prevalence and clinical features associated with depression in PD remain controversial. The purpose of this study is to estimate the prevalence of depressive symptoms in our patients, as related to other clinical data, and to assess clinical outcomes of these symptoms. A series of PD patients were evaluated over a 9-year period, using the Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn and Yahr stage (HY), Schwab and England Scale (SE), Mini-Mental State Examination (MMSE), and Yesavage Geriatric Depression Scale (GDS). Presence of depressive symptoms was considered if GDS score was higher than 10: mild-moderate (MD) for GDS scores between 11 and 20 and moderate-severe (SD) for GDS scores greater than 20. Three hundred and fifty-three patients were included in this study and additional follow up information was obtained for 184 patients. MD and SD were found in 40.2 and 16.7% of PD patients, respectively. Female gender, high HY, high UPDRS total and subtotal, and low MMSE and SE scores were significantly associated with depressive symptoms. According to changes in GDS score, 34% of patients remained stable, 35% showed an improvement, and 30.9% worsened in the follow up study. Gender, age, age of onset, HY, UPDRS, and PD duration are not related to depression outcome.

Visuo-motor coordination is normal in patients with major depression

Depression and Parkinson's disease (PD) are strongly associated with each other. Similarly, deficient visuo-motor coordination (VMC) accompanies PD from its earliest clinical stages. This double association suggests that a VMC dysfunction would be found in patients with major depression. Previous reports are ambiguous on this matter. Therefore, the present study was undertaken in order to determine whether MD patients pass or fail a VMC test on which PD patients are known to be deficient.Sixty-five MD patients were tested. Fifty-four (83%) had normal VMC. VMC was found to be independent of age, disease duration, severity of depression, or treatment. A deficit was found in 12 patients (17%). In this group too, VMC capabilities did not correlate with depression, or its treatment.These results negate an effect of depression, its accompanying frontal cortical changes, or its treatment on VMC. We propose that abnormal VMC in depression indicates coexisting illness, including possible preclinical PD.

Prevalence, etiology, and treatment of depression in Parkinson's disease

Parkinson's disease (PD) is primarily a disease of elderly individuals with a peak age at onset of 55 to 66 years. It is characterized by bradykinesia, rigidity, tremor, and postural instability; and affects approximately 1 million individuals in the US and is the second most common neurodegenerative disease next to Alzheimer's disease. The motor symptoms of PD are the focus of pharmacotherapy, yet the nonmotor symptoms (e.g., dementia, psychosis, anxiety, insomnia, autonomic dysfunction, and mood disturbances) can be the most disturbing, disabling, and misunderstood aspects of the disease. Depressive symptoms occur in approximately half of PD patients and are a significant cause of functional impairment for PD patients. There is accumulating evidence suggesting that depression in PD is secondary to the underlying neuroanatomical degeneration, rather than simply a reaction to the psychosocial stress and disability. The incidence of depression is correlated with changes in central serotonergic function and neurodegeneration of specific cortical and subcortical pathways. Understanding comorbid depression in PD may therefore add to the understanding of the neuroanatomical basis of melancholia.

Cognitive reserve modulates functional brain responses during memory tasks: a PET study in healthy young and elderly subjects

Cognitive reserve (CR) is the ability of an individual to cope with advancing brain pathology so that he remains free of symptomatology. Epidemiological evidence and in vivo neurometabolic data suggest that CR may be mediated through education or IQ. The goal of this study was to investigate CR-mediated differential brain activation in 17 healthy young adults and 19 healthy elders. Using nonquantitative H(2)(15)O PET scanning, we assessed relative regional cerebral blood flow while subjects performed a serial recognition memory task under two conditions: nonmemory control (NMC), in which one shape was presented in each study trial; and titrated demand (TD), in which study list length was adjusted so that each subject recognized shapes at approximately 75% accuracy. A factor score that summarized years of education and scores on two IQ indices was used as an index of CR. Voxel-wise, multiple regression analyses were performed with TD minus NMC difference PET counts as the dependent variable and the CR variable as the independent variable of interest. We identified brain regions where regression slopes were different from zero in each separate group, and also those where regression slopes differed between the two age groups. The slopes were significantly more positive in the young in the right inferior temporal gyrus, right postcentral gyrus, and cingulate, while the elderly had a significantly more positive slope in left cuneus. Brain regions where systematic relationships between CR and brain activation differ as a function of aging are loci where compensation for aging has occurred. They may mediate differential ability to cope with brain changes in aging.

Neuropsychiatric aspects of Parkinson's disease: recent advances

Psychiatric disturbances are a common feature of Parkinson's disease (PD), which is a degenerative disorder defined by its characteristic movement abnormalities. Its management is optimal when PD is viewed as a neuropsychiatric disorder, because this encourages consideration of the motor deficits along with its psychiatric and cognitive aspects. This review addresses the diagnosis and treatment of the most common psychiatric disorders in PD, and provides an update of related clinical research, including studies on neurosurgical treatments.

Auditory selective attention in young and elderly adults: the selection of single versus conjoint features

The effects of aging on the behavioral and neurophysiological correlates of auditory selective attention were investigated when selection was between either unidimensional or multidimensional stimuli. Attentional processes were studied by recording event-related brain potentials (ERPs) from 16 young (M = 22 years) and 16 elderly adults (M = 74 years) while they detected target tones based on a single location cue or a conjunction of location and pitch cues. Performance declined from the single- to the conjoint-cue task for both age groups but more so for the elderly. The ERP data showed that both age groups used a hierarchical processing strategy to perform the conjoint-cue task, but processing of the pitch dimension took longer for the elderly than for the young. The ERP data also showed that the scalp distribution of a late aspect of the waveform was more restricted in both anterior and posterior directions for the elderly. This suggests that frontal-lobe dependent attentional processes may be less efficacious with aging.

Association of life activities with cerebral blood flow in Alzheimer disease: implications for the cognitive reserve hypothesis

BACKGROUND

Regional cerebral blood flow (CBF), a good indirect index of cerebral pathologic changes in Alzheimer disease (AD), is more severely reduced in patients with higher educational attainment and IQ when controlling for clinical severity. This has been interpreted as suggesting that cognitive reserve allows these patients to cope better with the pathologic changes in AD.

OBJECTIVE

To evaluate whether premorbid engagement in various activities may also provide cognitive reserve.

DESIGN

We evaluated intellectual, social, and physical activities in 9 patients with early AD and 16 healthy elderly controls who underwent brain H(2)(15)O positron emission tomography. In voxelwise multiple regression analyses that controlled for age and clinical severity, we investigated the association between education, estimated premorbid IQ, and activities, and CBF.

RESULTS

In accordance with previous findings, we replicated an inverse association between education and CBF and IQ and CBF in patients with AD. In addition, there was a negative correlation between previous reported activity score and CBF in patients with AD. When both education and IQ were added as covariates in the same model, a higher activity score was still associated with more prominent CBF deficits. No significant associations were detected in the controls.

CONCLUSIONS

At any given level of clinical disease severity, there is a greater degree of brain pathologic involvement in patients with AD who have more engagement in activities, even when education and IQ are taken into account. This may suggest that interindividual differences in lifestyle may affect cognitive reserve by partially mediating the relationship between brain damage and the clinical manifestation of AD.

Stimulus characteristics and task category dissociate the anterior and posterior aspects of the novelty P3

The novelty P3 is an event-related potential component that is most often elicited by environmental sounds within the "novelty oddball" paradigm. Within the context of this paradigm, it is not clear if the novelty P3 can be elicited by deviant stimuli regardless of whether they serve as target or nontarget deviants, or to what extent the physical characteristics of the stimulus contributes to the amplitude of the novelty P3. The current study examines this issue by systematically switching target and nontarget deviants between environmental sounds and tonal stimuli. Participants were 36 young adults. Auditory stimuli were 48 unique tones and 48 unique environmental sounds presented under three experimental conditions. The results showed that target and nontarget deviants elicited novelty P3s with anterior and posterior aspects. The major determinant of the extent of the anterior aspect was the degree of difference between the physical characteristics of the deviant stimuli and the standards. By contrast, the major determinant of the posterior aspect was the task relevance of the deviant stimuli.

Opposite metabolic changes in the habenula and ventral tegmental area of a genetic model of helpless behavior

Congenitally helpless rats have been selectively bred to display an immediate helpless response to stress in order to model hereditary brain differences that contribute to depression vulnerability. Differences in regional brain metabolism between congenitally helpless and non-helpless rats were investigated using quantitative cytochrome oxidase histochemistry. The results indicated that congenitally helpless rats had 64-71% elevated metabolism in the habenula and a 25% elevation in the related interpeduncular nucleus. In contrast, helpless rats had 28% reduced metabolism in the ventral tegmental area (VTA) and 14-16% reductions in the basal ganglia and basolateral and central amygdala. The opposite metabolic changes in the habenula and ventral tegmental area may be especially important for determining the congenitally helpless rat's global pattern of brain activity, which resembles the metabolic activity pattern produced by dopamine antagonism.

Depression and Parkinson's disease: a new look at an old problem

A National Institutes of Health (National Institute of Neurological Disorders and Stroke; National Institute of Mental Health; National Institute on Aging) working group meeting focused on the non-motor aspects of Parkinson's disease (PD). Below is the summary of the meeting presentations and recommendations for a research agenda on the epidemiology, assessment, circuitry, therapeutic approaches, and clinical trials of Parkinson's disease co-morbid with depression. A second summary will focus on PD and dementia.

Depression in Parkinson's disease

Depression in Parkinson's disease (PD) is a common complication, with a major impact on quality of life. Failure to recognize and treat depression can lead to premature and inappropriate discontinuation of antiparkinsonian therapies. Cited frequency for depression in PD varies between 2.7 and 70%. Methodological differences account for much of the disparity. The aetiology of depression in PD is complex, with 'tonic' (slowly changing and persistent) and 'phasic' (short-lived and fluctuating) components. Both depression and anxiety may predate the onset of the motor disorder by some years. Hedonistic homeostatic dysregulation is a cyclical mood disorder associated with excessive intake of dopaminergic therapies, inappropriate for the motor state. Negative affective symptoms occur on attempted reduction of medication, reinforcing the abnormal medication pattern. The Montgomery-Asberg Depression Rating Scale and the Hamilton Rating Scale for Depression have good diagnostic sensitivity and specificity for assessing depression in PD. There is a dearth of sizeable, placebo-controlled studies for evaluating drug treatment of depression in PD. Dopaminergic drugs have variable antidepressant properties. Selective serotonin reuptake inhibitors are currently the most commonly prescribed group of antidepressants in the depressed PD patient. Depression in the PD patient may be associated with a more rapid deterioration in cognitive and motor functions.

Comorbidity of depression with other medical diseases in the elderly

A major factor in the context of evaluating depression in the elderly is the role of medical problems. With aging there is a rapid increase in the prevalence of a number of medical disorders, including cancer, heart disease, Parkinson's disease, Alzheimer's disease, stroke, and arthritis. In this article, we hope to bring clarity to the definition of comorbidity and then discuss a number of medical disorders as they relate to depression. We evaluate medical comorbidity as a risk factor for depression as well as the converse, that is, depression as a risk factor for medical illness. Most of the disorders that we focus on occur in the elderly, with the exception of HIV infection. This review focuses exclusively on unipolar disorder. The review summarizes the current state of the art and also makes recommendations for future directions.