Depression in patients referred to a dementia clinic. A three-year prospective study

Prevalence, symptom profile, and aetiology of depression in dementia sufferers

Ninety-two consecutive attenders at a day hospital for the assessment of dementia were assessed using the CAMDEX schedule. The prevalence of depression in the 58 dementia sufferers who fulfilled the entry criteria for the study was 24.1%. The prevalence of depression was similar in patients with senile dementia of Alzheimer's type and those with vascular dementia. Patients with minimal dementia were significantly more likely to suffer from depression than those with mild or moderate dementia but there was no significant association with insight. The symptom profile of patients with minimal dementia was significantly correlated to that of patients with mild dementia and both were similar to the symptom profiles previously described amongst the elderly with functional depression. Physical illness was not associated with depression in the current sample. The implications of the findings are discussed.

Monoamine neurons in aging and Alzheimer's disease

The integrity of dopaminergic, noradrenergic and serotonergic neurons in normal aging and Alzheimer's disease is reviewed. Loss of dopaminergic innervation of the neostriatum is a prominent age-related change, which corresponds with the age-related loss of dopaminergic cell bodies from the substantia nigra. This change is regionally specific, since dopaminergic innervation of the neocortex and the neostriatum are not affected. Although there is an age-related loss of noradrenergic cell bodies from the locus coeruleus, most studies indicate normal concentrations of noradrenaline in target areas. There is also evidence for reduced serotonergic innervation of the neocortex and, less convincingly, the neostriatum. Alzheimer's disease is associated with more pronounced noradrenergic and serotonergic denervation but, unlike normal aging, dopaminergic innervation of neostriatum is intact; although dopamine neurons are probably dysfunctional in this region. Studies relating neuronal markers to the symptomatology of Alzheimer's disease indicate that dysfunction of monoamine neurons is more closely linked to non-cognitive than to cognitive changes in behavior. In addition, monoaminergic therapies have been successful in ameliorating affective and psychotic behaviors along with sleep disturbances in both Alzheimer's disease and senescence. It seems likely that monoaminergic therapies (developed as we learn more about alterations in dopamine, noradrenaline and serotonin) will continue to be necessary to treat such behavioral disturbances.

Oral 5'-methyltetrahydrofolic acid in senile organic mental disorders with depression: results of a double-blind multicenter study

5'-Methyltetrahydrofolic acid (5'-MTHF) in addition to standard psychotropic medication significantly improved clinical recovery in depressed patients with borderline or definite folate deficiency, and significantly reduced depressive symptoms in elderly normofolatemic patients after 3 weeks of treatment. In this equivalence study the effect of 5'-MTHF on depressive symptoms and cognitive status was compared to Trazodone (TRZ) in normofolatemic elderly patients with mild to moderate dementia and depression. Ninety-six patients with dementia, scoring 12-23 at the Mini Mental State Examination (MMSE) and > or = 18 at the Hamilton Depression Rating Scale (HDRS) after a 2-week placebo run-in, were randomized to receive either 5'-MTHF (50 mg/day p.o.) (47 patients) or TRZ (100 mg/day p.o.) (49 patients) in a double-blind design for 8 weeks. HDRS was assessed before, after 4 weeks and at the end of treatment; Rey's Verbal Memory (RVM) test for immediate and delayed recall was evaluated before and after treatment. After 4 weeks of treatment HDRS score was reduced from 23 +/- 5 to 20 +/- 6 in the 5'-MTHF (p < 0.05 vs baseline), and from 23 +/- 3 to 21 +/- 4 in the TRZ group (p < 0.05 vs baseline). A further significant decrease to 18 +/- 6 and 19 +/- 5 respectively was obtained at the end of the treatment period (p < 0.05 vs week 4) with 5'-MTHF and TRZ.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical and neuropathological correlates of depression in Alzheimer's disease

Depressive symptoms have been reported in patients with mild to moderate Alzheimer's disease (AD). Recent evidence suggests that a noradrenergic deficit originating from neuronal degeneration in brainstem nuclei may represent an organic correlate of these disturbances. We examined the neuropathological changes in the locus coeruleus (LC), substantia nigra (SN), basal nucleus of Meynert and cortex of 52 patients (12 male, 40 female, mean age 83.2 +/- 6.4 years) with pathologically verified AD. Fourteen patients (1 male, 13 female) showed signs of depression. The majority of these patients suffered from severe physical disability or sensory impairment and developed persistent delusions, but had less cognitive impairment. Neuronal counts in the LC were significantly lower than in the 38 patients without depression (36.9 +/- 14.0; 51.4 +/- 28.0 neuromelanin-pigmented cells per section per nucleus; F = 3.4, df = 1, 50, P = 0.04). Neuron counts were higher in the basal nucleus of Meynert in depressed AD patients and there were no differences of the neuron numbers in the SN. Depression (main effect; F = 4.5, P = 0.04) contributed significantly to the variance of neuronal counts in the LC, even when covarying for gender, age of onset, cognitive impairment and cortical Alzheimer pathology. The observed disproportionate loss of noradrenergic and cholinergic neurons in the LC and basal nucleus of Meynert may represent an important organic substrate of depression in AD.

Plasma homocysteine in vascular disease and in nonvascular dementia of depressed elderly people

Depression among elderly people with reversible cognitive loss often manifests with concomitant vascular disease and can also precede the development of nonvascular degenerative dementia. Little is known about etiological factors for reversible or irreversible dementias in older depressed people. The amino acid homocysteine (HC), which is both a vascular disease risk factor and a precursor of the excitotoxic amino acids cysteine and homocysteic acid, could play a role in the pathophysiology of such individuals. Twenty-seven depressed elderly acute inpatients by DSM-III-R criteria had significantly higher plasma homocysteine levels and lower cognitive screening test scores than did 15 depressed young adult inpatients. HC was highest in the older patients who had concomitant vascular diseases (n = 14). HC was lowest in the older depressives who had neither vascular illnesses nor dementia (n = 8), comparable to the young adult depressives. Higher HC correlated significantly with poorer cognition only in the nonvascular geriatric patients (rs = -0.53). The findings extend earlier work showing higher HC in vascular patients from general medical populations, and also suggest a possible metabolic factor in certain dementias associated with late-life depression.

Regional cerebral blood flow abnormalities in depressed patients with cognitive impairment

Depression with cognitive impairment, so called depressive pseudodementia, is commonly mistaken for a neurodegenerative dementia. Using positron emission tomography (PET) derived measures of regional cerebral blood flow (rCBF) a cohort of 33 patients with major depression was studied. Ten patients displayed significant and reversible cognitive impairment. The patterns of rCBF of these patients were compared with a cohort of equally depressed non-cognitively impaired depressed patients. In the depressed cognitively impaired patients a profile of rCBF abnormalities was identified consisting of decreases in the left anterior medial prefrontal cortex and increases in the cerebellar vermis. These changes were additional to those seen in depression alone and are distinct from those described in neurodegenerative dementia. The cognitive impairment seen in a proportion of depressed patients would seem to be associated with dysfunction of neural systems distinct from those implicated in depression alone or the neurodegenerative dementias.

Subclinical dementia: relevance of cognitive symptoms and signs

In 1971 and 1972, a representative sample of 70-year-old people (n = 392) from a population study was rated with regard to psychiatric symptoms and signs. Subjects showing evidence of dementia of any degree, including slight and questionable, were excluded (n = 18). The remaining 374 subjects were followed longitudinally for 9 years. Thirty-eight subjects developed severe dementia during this period. They were compared to those who did not with regard to 19 reported and 17 observed items concerning general psychopathology, seven reported items concerning sleep, and a global rating of mental health. Five items correlated with the development of severe dementia: number of remembered dreams per week, latency of speech, speed of speech, difficulties in finding words, and memory for recent events. A stepwise logistic regression procedure demonstrated that a low frequency of remembered dreams, a reduced memory for recent events, and difficulties in finding words made independent contributions to the prediction of dementia. There were no differences with regard to affective items. There were no differences between the subjects who developed senile dementia of the Alzheimer type and those with multi-infarct dementia. The results thus support the hypothesis that symptoms pertaining to cognitive functions are the first to appear in the development of dementia.

Primary or depressive dementia: mental status screening

In the course of interviewing a patient, several aspects of everyday functioning must be covered to provide a range of observations necessary to suggest a provisional diagnosis. First organized by Adolf Meyer, the mental status examination consists of several techniques which, in recent times, have been shortened, structured and standardized to cover maximal ground in minimal time. In this article, the most popular scales are reviewed psychometrically for their capacity to detect, as first-stage instruments, cognitive impairment suggestive of primary dementia in the context of varying prevalence rates and confounding factors like sensory impairments, sociodemographics and depressive states. Several of the measures are found adequate in some respects though not in others, but all of the better ones, when used as front line implements during clinical intake, regularly improve detection over base rates. An analytical method modelled on ROC procedures is then described contrasting two of them before newer instruments are considered which aim to improve sensitivity at relatively little cost to specificity.

Depressive symptomatology and cognitive functioning: an epidemiological survey in an elderly community sample in France

As part of a 5-year, prospective, epidemiological survey of normal and pathological ageing, this cross-sectional analysis examines the relationship between depressive symptomatology (CES-D) and cognitive functioning (MMS) in a community sample of 2792 non-institutionalized persons (age greater than or equal to 65) living in Southwest France. Of the sample, 13.4%, report depressive symptoms above the cut-off. A significant association was found between CES-D and MMS scores, but after adjusting for age, living arrangements, and especially functional limitations, the relationship remained strong only for women.

Tailoring adult psychiatric practices to the field of geriatrics

The United States' population is aging. Epidemiological surveys suggest significant rates of mental illness amongst the rapidly growing over-65 cohort. A burgeoning experience and data base related to the developing sub-discipline of geriatric psychiatry is now available. This article synthesizes key issues and concepts as an introduction to geropsychiatric practice-in particular, a) the interface between medical illness and psychiatric expression in the elderly, b) delirium, c) dementia, and d) depression-and considers their interactions. Finally, there is a brief overview of geriatric psychopharmacology, followed by clinically-oriented discussions of each of the major classes of psychotropics as applied to a geriatric population.

Potentially reversible dementia: a review

Potentially reversible dementia is reviewed with reference to diagnosis, causes and outcome. Many disorders which cause cognitive impairment, such as drug toxicity and depression, fail to meet diagnostic criteria for dementia. These tend to have the best prognosis. Studies of the neuropsychiatric syndromes associated with disorders causing potentially reversible dementias suggest that dementia is an infrequent outcome and when it does occur, few cases recover. Factors predictive of improvement are short duration of symptoms and mild degree of cognitive impairment, usually subcortical in type. It is suggested that potentially reversible cognitive impairment would be a more accurate term as many cases are due to delirium and depression. While cases of well established dementia do not require extensive investigation, all cases should have a thorough clinical assessment as in many instances dual pathology exists and all require psychosocial management.

The TRH stimulation test in Alzheimer's disease and major depression: relationship to clinical and CSF measures

A blunted thyroid-stimulating hormone (TSH) response to exogenous thyrotropin-releasing hormone (TRH) has been reported to occur consistently in patients with major depression and less consistently in patients with Alzheimer's disease (AD). In this study we compared the TSH response to TRH in a large group (n = 40) of AD patients, elderly patients with major depression (n = 17), and age-matched controls (n = 14) to further characterize how it may relate to clinical variables, baseline thyroid function tests, and cerebrospinal fluid measures. Comparisons of TRH stimulation test response across all three groups revealed that patients with major depression had lower stimulated TSH levels (delta maxTSH) (p less than 0.02) and higher (though still within normal limits) mean thyroxine (T4) levels (p less than 0.05) than the AD patients or controls. AD patients with a blunted TSH response had a significantly higher mean free T4 (FT4) level (p less than 0.03) and tended to be more severely demented (p less than 0.01) than those with a nonblunted response.

CSF monoamine metabolites and somatostatin in Alzheimer's disease and major depression

Decreased cerebrospinal fluid (CSF), somatostatinlike immunoreactivity (SLI) and alterations in the CSF monamine metabolites 3-methoxy-4-hydroxyphenylethylglycol (MHPG), 5-hydroxyindoleacetic acid (5-HIAA), and homovanillic acid (HVA) have been reported in patients with probable Alzheimer's disease (AD) and in patients with major depression. In this study, we found CSF SLI to be significantly lower in a large group of AD patients (n = 60) and in a group of age-matched patients with major depression (n = 18) as compared with normal controls (n = 12). Mean CSF, MHPG, 5-HIAA, and HVA levels were not significantly different among diagnostic groups. Within a group of "depressed" AD patients, CSF levels of 5-HIAA showed a significant positive correlation (p = 0.03) with CSF SLI; a similar relationship was found within the group of patients with major depression. Further exploration of the relationship between the somatostatin and serotonin systems may provide clues as to how neuropeptides interact with monoamine neurotransmitters and what role they have in depression.

The occurrence of different intrusive errors in patients with Alzheimer's disease, multiple cerebral infarctions, and major depression

Recent evidence suggests that specific types of intrusive errors may occur more often in the protocols of Alzheimer's disease (AD) patients than in those of patients diagnosed with other types of dementia. Using the FULD Object Memory Evaluation, we documented the occurrence of five qualitatively different types of intrusive errors for mildly and moderately impaired patients with AD and multiple cerebral infarctions (MCI). Depressed and normal elderly controls were also studied. Despite an equivalent degree of impairment on a broad array of neuropsychological measures, mildly impaired AD patients evidenced greater deficits on a measure tapping retrieval from semantic memory and demonstrated a higher occurrence of specific types of intrusive errors relative to their mildly impaired MCI counterparts. Further, both of these measures were highly correlated, suggesting that these indices may be particularly sensitive to semantic dysfunction associated with early AD.

Psychiatric symptoms in cases of clinically diagnosed Alzheimer's disease

All incident cases of clinically diagnosed Alzheimer's disease were identified through the unique record linkage system of the Mayo Clinic. Thirty-nine (32%) of the sample of 122 had a psychiatric history that preceded the onset of CDAD by at least 3 years. Twenty-five percent of the study population had had an episode of delirium within 2 years of the onset of CDAD. Eighty-four percent of the cases had psychiatric symptoms in the course of CDAD that were documented in their medical records. Specific symptom patterns included agitation, combativeness, confusion and disorientation, depression, psychosis, and wandering. These symptoms occurred more frequently in clusters than singularly.

Personality alterations in multi-infarct dementia

Multi-infarct dementia (MID) produces changes in intellectual function and in overt behavior, but alterations in demeanor have received little systematic investigation. In this study, an assessment of personality change occurring after the onset of the dementia was performed using an inventory completed by the subjects' spouses. Personality alterations in MID were compared to those occurring in a group of healthy elderly individuals. Twelve of the 18 inventory items changed more in the MID patients than in normal control subjects. Personality changes are a consistent part of the clinical syndrome of MID and occur early in the course of the disease.

Automatic memory processes in patients with dementia-Alzheimer's type (DAT)

We examined patients with Dementia-Alzheimer's Type, depression, and matched controls on tasks designed to compare automatic (monitoring frequency and modality) and effortful (free recall) processing of words and pictures. The results demonstrated that depressed patients performed poorly only when conditions required effortful processing, but DAT patients performed poorly under all conditions. There was almost no overlap in scores between DAT and elderly depressed patients on one of the measures of automatic processing suggesting that this measure may be clinically useful. The results suggest that automatic memory processes can be partially dissociated from effortful memory processes, but that both types of operations are impaired in DAT patients.

Neuropsychological deficits and CT scan changes in elderly depressives

A number of computerized tests were used to study visual attention, memory and learning in elderly depressed patients. Impairment was found in approximately 70% of depressed patients and was seen particularly in memory and in measures of latency. Depressed patients showed equivalent impairment in short-term memory but less impairment in conditional associative learning compared to a group of patients with early dementia of the Alzheimer-type (DAT), matched for age and pre-morbid IQ. With respect to qualitative differences between depression and DAT, depressed patients showed a different pattern of errors and a consistently prolonged latency of response which was independent of delay in a delayed matching-to-sample test. On recovery from depression, although improvement was seen in most test scores, performance in measures of latency and in a number of tests of memory and learning failed to reach the level seen in a group of matched control subjects and approximately 35% of patients continued to show impairment. For the depressed patients, ventricular brain ratio (VBR) correlated with measures of slowing. In addition, in the 'recovered-depressives', VBR correlated with poor performance at high levels of task difficulty. These findings are discussed with respect to previous literature on the pattern of cognitive impairment and CT scan findings in depression.

Psychiatric phenomena in Alzheimer's disease. IV: Disorders of behaviour

Out of a sample of 178 patients with AD, aggression was present in 20%, wandering in 19%, binge-eating in 10%, hyperorality in 6%, urinary incontinence in 48%, and sexual disinhibition in 7%. Behavioural abnormalities were greater in those with more severe dementia. Temporallobe atrophy correlated with aggression, and widening of the third ventricle with hyperorality. Features of the Kluver-Bucy syndrome were commonly seen, but the full syndrome occurred in only one subject. Patients with at least one feature of the Kluver-Bucy syndrome had greater temporal-lobe atropy than those without any of the features.

Cognitive impairments and depression in Parkinson's disease: a follow up study

The presence of depression and cognitive impairments was examined in seventy patients with Parkinson's disease (PD). Forty nine patients of this original cohort were re-examined between three and four years after the first evaluation. While both depressed and non-depressed patients showed a significant decline in cognitive function during the follow up period, intellectual decline was significantly more severe for the depressed group. Depressed patients also showed a faster rate of progression of motor signs (mainly tremor) than the non-depressed group. Patients that died during the follow up period showed significantly more cognitive impairments than patients who were alive at follow up. These findings suggest that either there may be two forms of PD: one with depression and rapid cognitive decline and one without depression and a gradual cognitive decline; or that the mechanisms of cognitive impairment in PD and depression may interact to produce a more rapid evolution in cognitive impairment among PD patients with a previous depression than among patients without a previous depression.

The effectiveness of services and treatment in psychogeriatrics

The future development of new psychogeriatric services in Australia may well depend upon the demonstration of their potential effectiveness and efficiency. Descriptive accounts of effective services provide ample guidelines, although formal evaluation is lacking. Examining the major psychiatric disorders of the elderly shows that most are functional. Effective acute psychiatric treatment is available for these. In dementia cases, effective therapies exist for the reduction of secondary behavioural disabilities in the sufferer and the stress on carers. Adequately resourced comprehensive psychogeriatric services would be best equipped to deliver such treatments.

A questionnaire investigation of anxiety and depression in early dementia

We report findings on a study of anxiety and depression by questionnaire in 50 patients with mild dementia and 134 control subjects using the Hospital Anxiety and Depression Scale. Thirty-eight percent of patients and 9% of controls had a possible or probable diagnosis of an anxiety disorder. Possible or probable depression was found in 28% of the patients and 3% of the controls. These rates for the patients were above those in normal populations. All patients and control subjects were tested with the Extended Scale for Dementia (ESD). Neither group showed a significant relationship between depression and ESD scores. In the control subjects there was a negative correlation (P less than .006) between anxiety and cognitive scores, one that was not found in the patients.

Instruments for the functional assessment of older patients

Structured assessment instruments are particularly useful in screening for problems that often go undetected in older patients. In addition, such instruments can provide information about conditions and abilities or limitations that are not regularly assessed in standard clinical practice. Often, their administration is delegated to other health professionals, but these tools still provide useful information to the physician. Clinicians should view assessment instruments as they would any other clinical test. They should be familiar with the strengths, weaknesses, and precision of any test used and understand how best to use the test as an adjunct to clinical practice. In addition, clinicians must learn to focus on functional status, in terms of both assessment and outcome, in their care of older patients.

Vitamin B12 and folate status in acute geropsychiatric inpatients: affective and cognitive characteristics of a vitamin nondeficient population

This chart review study examined the serum vitamin B12 and folate status of 102 geriatric patients newly admitted to a private psychiatric hospital. Only 3.7% were B12 deficient and 1.3% were folate deficient; 4% were anemic. Nevertheless, those with below-median values of both vitamins had significantly lower Mini-Mental State scores than patients higher in one or both vitamins. Patients with "organic psychosis" with a negative family history for psychiatric disorder had significantly lower B12 levels than those with a positive family history. In major depression, folate levels correlated negatively with age at onset of psychiatric illness and length of hospitalization. These data suggest that (1) biochemically interrelated vitamins such as B12 and folate may exert both a separate and a concomitant influence on affect and cognition; (2) poorer vitamin status may contribute to certain geropsychiatric disorders that begin at a later age and lack a familial predisposition.

Assessment of behavioral and affective symptoms in Alzheimer's disease

Noncognitive behavioral symptoms occurring during the prior week were studied in 34 Alzheimer's disease (AD) patients and 21 spousal control subjects via caregiver and patient interviews using the Behavioral Pathology in Alzheimer's Disease Rating Scale and the Cornell Scale for Depression in Dementia. Delusional or paranoid features were reported in 13 subjects (38%) and hallucinations in six (18%); patients with these psychoticlike symptoms had lower scores on the Folstein's Mini-Mental State Examination. Other behavioral symptoms reported in AD patients included anxiety (50%) and activity disturbances (44%). Six AD subjects (18%) and two controls (10%) showed mild to moderate symptoms of depression; AD subjects were more likely than controls to show behavioral signs and symptoms of depression, but the two groups did not differ in terms of mood-related, cyclical, or physical signs and symptoms.

Nonmedical complications of diagnostic workup for dementia [clinic conference]

Testing for patients presenting with dementias can lead to diagnosis of disorders that can contribute to cognitive dysfunction, and to improvement, stabilization, or slowed deterioration in some demented patients. However, possible benefits must be balanced against possible costs. The present recommendations for workup of patients with dementia includes some tests with only marginal benefits, and a more limited workup may be as effective. This case demonstrates how important it is to be sensitive as well to possible effects on family relationships of demented patients. When we evaluate and treat demented patients, the dependence of the demented patient on the caregiver and the emotional and physical stresses experienced by many caregivers make it important to consider the patient and caregiver as a system vulnerable to many potential risks.

Depression in late life: age of onset as marker of a subtype

Late-onset depression may be pathogenetically and prognostically distinct from early-onset, recurrent affective disorder. The authors reviewed records of 94 consecutively admitted unipolar major depressives over the age of 60 years, divided subjects into groups based on their age of onset, and examined demographic and clinical features. Late-onset elderly depressives had a lower incidence of family history of affective illness, longer hospital stay, and more residual symptoms at discharge. However, there was no demonstrable relationship between age of onset and presence of psychosis, melancholia, medical illness, symptom severity at admission, or indicators of neuropathology. Although late-onset elderly depressives did less well than those with early-onset illness, the data do not support the notion of late-onset depression as a distinct pathological process.

Structural brain CT changes and cognitive deficits in elderly depressives with and without reversible dementia ('pseudodementia')

Twenty-six elderly (greater than 60 yrs) patients with DSM-III major depression were compared to 13 patients with NINCDS/ADRDA probable Alzheimer's disease (AD), and to 31 screened normal controls. Subjects were matched on age and sex. Fifteen of the 26 depressed patients were cognitively impaired on the Mini-Mental State Examination (MMSE) upon admission, but after treatment returned to the normal range. These 15 patients were defined as having the dementia syndrome of depression (DOD). The remaining 11 depressed patients were termed depressed, cognitively normal (DCN). All subjects received standardized cranial CT scans for assessment of ventricular brain ratio (VBR) and CT attenuation numbers. Subjects also received neuropsychological evaluation. CT values for the 26 depressed patients lay between those of AD patients and normal controls. CT values for the DOD subgroup clustered near those of AD patients. Patterns of cognitive deficits and correlations of CT attenuation values with cognitive measures were also similar in AD and DOD. Most patients were reassessed at a mean of two years after initial testing; of the 11 of the 15 DOD re-examined, only one had undergone cognitive decline. By contrast, all AD patients retested had declined significantly. Episodes of DOD and DCN tended to 'breed true'. This study suggests that while patients with DOD may have underlying structural brain abnormalities, obvious short-term progression to AD does not commonly occur.

Differential responsivity of mood, behavior, and cognition to cholinergic agents in elderly neuropsychiatric populations

To evaluate the possible differential responsivity of Alzheimer patients to cholinergic agents, a series of pharmacologic challenge studies in 83 neuropsychiatric patients and controls were performed contrasting a cholinergic antagonist (scopolamine) with two cholinergic agonists (arecoline and nicotine). Alzheimer patients displayed significantly greater behavioral and cognitive responses to central cholinergic blockade at lower scopolamine doses than age-matched controls or elderly depressives. These differential changes could not be explained by group differences in the sedative, physiologic, or pharmacokinetic effects of the drug. In addition, the elderly, age-matched control subjects did reveal a profile of cognitive deficits at the highest dose (0.5 mg), which temporarily mimicked the baseline impairments found in early Alzheimer's disease. Together, these findings with scopolamine suggest an increased sensitivity to cholinergic blockade in Alzheimer's disease and demonstrate the first direct evidence of anticholinergic modelling of dementia in normal elderly subjects. To investigate further the postsynaptic cholinergic responsivity in Alzheimer's disease, patients were studied with arecoline and nicotine. While the cognitive effects of both agents were modest at best, there were significant differences in mood and behavioral responses between arecoline and nicotine in Alzheimer subjects. These behavioral changes occurred at much lower doses in the Alzheimer patients than those required in normal controls, once more supporting the notion of increased behavioral sensitivity to cholinergic agents in Alzheimer's disease. In addition, the differential mood effects between these two cholinergic agonists raise new questions about receptor selectivity in the cholinergic regulation of mood.

Cornell Scale for Depression in Dementia

The Cornell Scale for Depression in Dementia is introduced. This is a 19-item clinician-administered instrument that uses information from interviews with both the patient and a nursing staff member, a method suitable for demented patients. The scale has high interrater reliability (kw = 0.67), internal consistency (coefficient alpha: 0.84), and sensitivity. Total Cornell Scale scores correlate (0.83) with depressive subtypes of various intensity classified according to Research Diagnostic Criteria.

The screening of cognitive impairment in the elderly: a critical review of current methods

The continued appearance of new screening tests for dementia suggests both the continuing need for a valid measure of pathological cognitive change and dissatisfaction with what is currently available. A brief review of current tests is presented which focuses on the major theoretical and methodological issues which have impeded the development of adequate screening instruments. Strategies for the management of such difficulties are also indicated, with a view to guiding prospective researchers in this field and increasing the critical perspective of those currently using these instruments.

The psychiatric symptoms of Alzheimer's disease

The authors used a semistructured interview administered to primary family caregivers to assess the prevalence and nature of psychiatric pathology in 175 well-diagnosed community-residing Alzheimer's disease patients. Symptoms that are indicative of depression in the cognitively intact were virtually ubiquitous in this demented population. A variety of psychotic features were also regularly reported. The implications of these findings for the recognition and treatment of reversible psychiatric impairment are discussed.

Suspected dementia: evaluation of 323 consecutive referrals

A neurological outpatient department studied 323 consecutive referrals for suspected dementia: 135 (41.8%) were not demented. Of the patients 12.1% had diffuse cognitive disorder; 10.2% circumscribed memory disorder; 0.9% other circumscribed cognitive disorder, 14.2% psychiatric disorder, and 4.3% were judged to be normal. Of the nondemented, 44.1% had a potentially treatable cause for their cognitive symptoms; in 27.4% it was depression. The total of demented patients was 188 (58.2%): 38.8% had primary degenerative dementia; 37.2% vascular dementia including combined degenerative and vascular dementia; and 23.4% had a specific cause. Patients with specific cause were significantly younger than those with other causes of dementia. A potentially treatable cause was found in 10.7% of all demented patients, the most common being metabolic disorders, meningioma, hydrocephalus, subdural haematoma, and depressive pseudodementia.

Psychomotor slowing and subcortical-type dysfunction in depression

Elderly patients with major depression and normal controls completed the Sternberg short-term memory scanning procedure and WAIS Digit Symbol. Depressed patients demonstrated psychomotor slowing on both tasks, but normal response latency as a function of memory set size on the Sternberg procedure. While cognitive-behavioural slowing may be observed in both depressive illness and subcortical neurological disorders, a normal rate of processing information centrally appears to distinguish depression from certain of these disorders. Psychomotor slowing in the presence of normal information processing speed might be explained by a deficit in motivational state associated with depression.