Apraxia testing to distinguish early Alzheimer’s disease from psychiatric causes of cognitive impairment

Objective: Mood- and stress-related disorders commonly cause attentional and memory impairments in middle-aged individuals. In memory testing, these impairments can be mistakenly interpreted as symptoms of dementia; thus, more reliable diagnostic approaches are needed. The present work defines the discriminant accuracy of the Dementia Apraxia Test (DATE) between psychiatric conditions and early-onset Alzheimer’s disease (AD) on its own and in combination with memory tests. Method: The consecutive sample included 50–70-year-old patients referred to dementia investigations for recent cognitive and/or affective symptoms. The DATE was administered and scored as a blinded measurement, and a receiver operating curve analysis was used to define the optimal diagnostic cut-off score. Results: A total of 24 patients were diagnosed with probable AD (mean age 61 ± 4) and 23 with a psychiatric condition (mean age 57 ± 4). The AD patients showed remarkable limb apraxia, but the psychiatric patients mainly performed at a healthy level on the DATE. The test showed a total discriminant accuracy of 87% for a total sum cut-off of 47 (sensitivity 79% and specificity 96%). The limb subscale alone reached an accuracy of 91% for a cut-off of 20 (sensitivity 83% and specificity 100%). All memory tests were diagnostically less accurate, while the combination of the limb praxis subscale and a verbal episodic memory test suggested a correct diagnosis in all but one patient. Conclusions: Apraxia testing may improve the accuracy of differentiation between AD and psychiatric aetiologies. Its potential in severe and chronic psychiatric conditions should be examined in the future.publishedVersionPeer reviewe

Attentional bias towards interpersonal aggression in depression - an eye movement study

Depressed individuals exhibit an attentional bias towards mood-congruent stimuli, yet evidence for biased processing of threat-related information in human interaction remains scarce. Here, we tested whether an attentional bias towards interpersonally aggressive pictures over interpersonally neutral pictures could be observed to a greater extent in depressed participants than in control participants. Eye movements were recorded while the participants freely viewed visually matched interpersonally aggressive and neutral pictures, which were presented in pairs. Across the groups, participants spent more time looking at neutral pictures than at aggressive pictures, probably reflecting avoidance behavior. When the participants could anticipate the stimulus valence, depressed participants - but not controls - showed an early attentional bias towards interpersonally aggressive pictures, as indexed by their longer first fixation durations on aggressive pictures than on neutral pictures. Our results thus preliminarily suggest both an early attentional bias towards interpersonal aggression, which is present, in depressed participants, also when aggression contents are anticipated, and a later attentional avoidance of aggression. The early depression-related bias in information processing may have maladaptive effects on the way depressed individuals perceive and function in social interaction and can, therefore, maintain depressed mood

Effects of a short psychological intervention on social attention in depression : an eye-tracking study

Tämän tutkimuksen tavoitteena oli tutkia lyhyen psykologisen intervention vaikutusta siihen, kuinka masennuksesta kärsivien huomio jakautui aggressiota tai prososiaalista käyttäytymistä sisältävien kuvien välillä. Kaksi masentuneista osallistujista koostuvaa ryhmää osallistui kahdesti huomion kohdistamista kartoittavaan silmänliiketutkimukseen. Alkumittaus suoritettiin ennen tutkimusryhmän (n=13) terapian alkamista. Jälkimittaus suoritettiin tutkimusryhmän saatua terapiansa loppuun, ennen kontrolliryhmän (n=15) terapian alkua. Tehtävä oli molemmilla kerroilla sama molemmille ryhmille. Osallistujia pyydettiin katsomaan hiljaa kun heille esitettiin kolmekymmentä kuvaparia. Kutakin aggressiivisesta ja prososiaalisesta kuvasta koostuvaa paria esitettiin viiden sekunnin ajan. Samat näyttelijät esiintyivät samassa ympäristössä kuvaparin molemmissa kuvissa. Tarkoitus oli että vain vuorovaikutuksen luonne erottaisi kuvat toisistaan. Kokeen aikana silmänliikekamera tallensi osallistujan oikean silmän liikkeitä. Aineistosta erotettiin kuusi tarkkaavaisuuden kohdistamista eri tavoin kuvaavaa muuttujaa. Kaikilla osallistujilla diagnosoitiin masennus (ICD-10) ennen tutkimuksen alkua. Mielialasta kerättiin tietoa myös kyselylomakkeilla (BDI-II, DASS-D, DASS-A, DASS-S). Tutkimusryhmän saatua terapiansa päätökseen kaikki osallistujat täyttivät kyselylomakkeet uudelleen ja myös diagnostinen tutkimus uusittiin. Yhdeksällä osallistujalla ei enää diagnosoitu masennusta. Heistä kahdeksan oli tutkimusryhmästä. Myös kyselylomakkeiden valossa tutkimusryhmäläisten mielialaoireet olivat selvästi helpottaneet. Silmänliikemuuttujien kohdalla molemmissa ryhmissä havaittiin taipumusta katsoa ensin aggressiota sisältävää kuvaa. Muutoin havaittiin lievää taipumusta katsoa enemmän prososiaalista kuvaa. Hyvästä hoitotuloksesta huolimatta silmänliikemuuttujissa ei havaittu interventiovaikutusta.The aim of this study was to investigate the effect of a short psychological intervention on depressed participants´ allocation of attention between scenes of prosocial or aggressive behavior. Two groups of depressed individuals took twice part in an attentional bias experiment using eyetracking (ET) methodology. The first experiment took place before study group (n=13) received the therapy. The second experiment took place after study group finished their therapy and before control group (n=15) received theirs. The task was similar both times and for both groups. The participants were asked to watch silently as they were shown thirty pairs of pictures. Each pair was presented for 5s and consisted of an aggressive and prosocial picture. The setting and actors were same in both pictures, only difference being the nature of interaction. During experiment an eyetracking camera recorded eye-movements from participant´s right eye. 6 variables reflecting different aspects of attentional bias were extracted from eye-movement data. All participants were diagnosed with major depressive disorder (MDD, ICD-10) before the study. Self-measure data about participants´ mood was also collected (BDI-II, DASS-D, DASS-A, DASS-S). After the study group had finished with therapy, all participants again filled in the self-measure studies and they were also examined for MDD diagnosis again. 9 participants didn´t receive the diagnosis anymore, 8 of those from the study group. Also the mean scores in self-measure scales were significantly lower for study group. For eye-tracking variables, both groups showed a tendency to make the first fixation on the aggressive picture. Otherwise a slight preference for the prosocial picture was seen. Despite success in alleviating depression, no intervention effect was observed in attentional biases

The dementia apraxia test can detect early-onset Alzheimer's disease

OBJECTIVE: Limb apraxia is a common early sign of Alzheimer's disease (AD) and is thought to occur specifically in early-onset (before the age of 65) AD. The Dementia Apraxia Test (DATE), a test of limb and face praxis developed to support the differential diagnosis of dementia, has shown good diagnostic accuracy in detecting AD in older patients, but it has not been validated for younger age groups. We investigated how accurately DATE can detect AD in middle-aged individuals and whether apraxia is a distinctive feature in early-onset AD. METHOD: A sample of mild-stage AD patients (n = 24; Mage = 61, SD = 4) was drawn from a prospective consecutive series of individuals referred to our neurology clinic for dementia investigations. A healthy comparison group (HC) of comparable age (n = 22; Mage = 61, SD = 7), sex distribution, and education was recruited. DATE was administered as a blinded experimental measure, and a receiver operating characteristic (ROC) analysis was used to define the optimal diagnostic cutoff point. RESULTS: The DATE classified 93% of the participants correctly as AD or HC (sensitivity 0.88, specificity 1.00, area under curve 0.968). The optimal diagnostic cutoff point was higher (49 points) than in a previous sample of older patients (45 points). Early onset did not seem to be associated with worse praxis performance in AD. CONCLUSIONS: DATE is an accurate tool for detecting early-onset AD within 2 years of symptom onset. The diagnostic cutoff point should be higher for middle-aged populations than for late-onset AD. (PsycInfo Database Record (c) 2023 APA, all rights reserved).acceptedVersionPeer reviewe

Attentional bias towards interpersonal aggression in depression : an eye movement study

Depressed individuals exhibit an attentional bias towards mood-congruent stimuli, yet evidence for biased processing of threat-related information in human interaction remains scarce. Here, we tested whether an attentional bias towards interpersonally aggressive pictures over interpersonally neutral pictures could be observed to a greater extent in depressed participants than in control participants. Eye movements were recorded while the participants freely viewed visually matched interpersonally aggressive and neutral pictures, which were presented in pairs. Across the groups, participants spent more time looking at neutral pictures than at aggressive pictures, probably reflecting avoidance behaviour. When the participants could anticipate the stimulus valence, depressed participants – but not controls – showed an early attentional bias towards interpersonally aggressive pictures, as indexed by their longer first fixation durations on aggressive pictures than on neutral pictures. Our results thus preliminarily suggest both an early attentional bias towards interpersonal aggression, which is present, in depressed participants, also when aggression contents are anticipated, and a later attentional avoidance of aggression. The early depression-related bias in information processing may have maladaptive effects on the way depressed individuals perceive and function in social interaction and can therefore maintain depressed mood.peerReviewe