subjective cognitive decline (SCD)

What is SCD?

Perceived decline in mem and/or other cognitive abilities relative to previous level of performance, w absence of OBJECTIVE neuropsych deficits ; not clinically diagnoses, js marker of aging rly

How do ppl from SCD differ from ppl without?

Those w SCD have an increased likelihood of biomarker abnormalities consistent w AD pathology and an increased risk for future pathological cognitive decline and dementia

What does the difference between ppl w SCD and those without mean?

Those w SCD have increased risks and this could be the earliest (pre symptomatic) stage of AD / other dementias

Inclusion criteria for pre-MCI SCD

Self-experienced persistant decline in cogn capacity compared w previous normal status (not related to specific event) AND normal age, gender, education adjusted performance on standardized cogn tests (for MCI / AD)

Exclusion criteria for pre-MCI SCD

MCI, prodromal AD, dementia (OBJECTIVE cognitive impairment) and/or if condition explained by psych / neuro disorder, disease, meds, substance use

How is SCD assessed?

Multiple ways — single question, multiple questionnaires, etc.

Considerations for assessing SCD (3)

Length of time covered (compared to 2 weeks or 10 yrs before for ex) ; self/informant report ; domains being asked abt (ex: have u noticed changes in ur thinking)

What is SCD associated to in relation to neuroimaging and biomarkers? (3)

Reductions in cerebral spinal fluid (CSF), atrophy in medial / prefrontal regions, elevated CSF tau protein

What is a greater number of AMYLOID burden associated to? (SCD and neuroimaging / biomarkers)

To greater number of memory complaints on questionnaires

Higher level of cognitive complaints were associated to what (SCD neuroimaging / biomarkers)

To decreased GRAY MATTER density in left/right hippocampi → could be early sign of decline/dementia bc it looks like MCI

Is education a protective factor in SCD?

No

Increased AND reduced glucose metabolism in SCD (PET) may reflect what?

Compensation that precedes eventual hypometabolism (cells slow down converting to energy)

What interaction is driving the effect of memory complaints?

Interaction of E4 allele and subjective risk factors

What is the role of temporal stability? (Outcomes)

If u complain abt cognitive decline multiple times over time and its consistent, then u prob acc have smth (increased risk)

What is the role of worries? (Outcomes)

If ur worried abt cognitive decline multiple times overtime, then u prob actually have smth

Temporal stability and worries (outcome)

consistent SCD and worry, inconsistent SCD and worry, consistent SCD and not worry, inconsistent SCD and not worry

Up to ___% of ppl w SCD decline to MCI / AD over 15 yr period

60

Factors that increase the likelihood of preclinical AD in SCD

Subjective decline in mem (rather than other domains), onset SCD within past 5 yrs, onset over 60 yrs, worries associated w SCD, feeling of being worse than age grp, E4 genotype, biomarker of AD, confirmation of decline by informant

Additional factors in prognosis of SCD (7)

Depression, anxiety, personality, health concerns, education, linguistic and cultural factors

Depression (additional factor in prognosis of SCD)

Can include symptoms of perceived/actual cogn impairment — early episodes increase risk for later cogn declines ; late life depression may be prodrome of AD / dementias & associated w increased risk of all-cause dementia ; associated w objective changes to brain structure/function

Higher levels of anxiety in AB+ patients is associated with?

Significantly more pronounced slopes of cognitive decline

Elevated SCD + high amyloid + high anxiety = ?

Ppl w rapidly declining cognition

Anxiety can reflect underlying dysfunction of HPA axis (cortisol controller)

High stress in midlife associated w HPA axis dysfunction (cortisol no work) → greater risk for AD

Higher neuroticism =

Structural brain changes (including in AD brain regions)

Higher conscientiousness =

Greater volumes in AD brain regions

neuroticism and complaints + amyloid burden

Ppl w high neuroticism show positive association w complains and amyloid burden

Chronic health difficulties and cognitive complaints

Cognitive complaints more associated w physical health symptoms than objective impairment

Chronic pain and the influence on self-reports of cognitive complaints

Can influence it bc of direct experience of pain symptoms, effect of pain meds on cognition, or comorbidity of depression and anxiety

Amyloid burden and SCD relationship is stronger in ppl w more education

True

Highly educated ppl may be more sensitive to subtle declines in cognitive function

True

Higher levels of education are associated w greater risk of decline to AD

True

Little is known about different cultural expressions of SCD and cognitive complaints are less socially sanctioned in different cultures

True

Problem with speed of tasks for mental function in other cultures

It may not be intrinsic to the cognitive process elsewhere

Neuropsych constructs are not differentially expressed across cultures

False

For ppl w AD, intervention or prevention could slow rate of incipient decline to preserve cognitive and functional abilities

True

How to compensate for mild memory difficulties (interventions)

Teach strategies like cognitive rehab for injuries (doesn’t change underlying mem system, but helps)

How to improve perceived memory function (interventions)

Enhance and recruit other cognitive functions like attention for ex

Other interventions to help SCD

Managing mood/anxiety, personality, and health concerns that contribute to it