Introduction
Metamemory refers to the ability to monitor or make judgments about one’s own memory processes [
1‐
3] and is neutral in its valence about the subjective judgment. In contrast, subjective memory impairment (SMI) or complaints specifically refer to a non-functional state of memory, and subjective cognitive decline (SCD) describes self-perceived worsening of cognition in general or memory specifically. Although these terms are frequently used interchangeably, distinctive elements of SMI have been associated with the affective component of worries or satisfaction and impact on everyday life [
4,
5].
SMI is frequently reported in many neurological disorders, e.g., epilepsy [
6], Parkinson’s disease [
7], or multiple sclerosis [
8], but can also increase with age [
9]. In memory clinics, clinicians face the challenge that sometimes memory complaints cannot be objectified by standard neuropsychological assessments, but still precede future cognitive decline. Indeed, research from large populations [
10] and individuals with increased biomarker-based risk for Alzheimer’s disease [
11,
12] indicates that subjective memory decline is associated with an increased risk for conversion to mild cognitive impairment and dementia even in cognitively unimpaired people [
5,
13]. Furthermore, SMIs are associated with an Alzheimer’s disease-like gray matter atrophy pattern [
14] and medial temporal lobe volume loss [
11,
15]. Beside this potential for identifying cognitive decline earlier than standardized cognitive tests, SMI can also be a more individualized approach to assessing everyday impairment, especially in high-performing individuals lacking baseline assessments [
16,
17].
To operationalize subjective memory, existing approaches vary regarding covered domains and time frames, administration modes, and number and phrasing of items and answer scales [
4]. Common methods include asking for a judgment of the extent of memory decline, e.g., Memory Complaint Questionnaire [
18], memory complaint frequency, like in the Complainer Profile Identification [
19], or rating how often memory-related tasks present a problem, e.g., Memory Functioning Questionnaire [
20]. Some approaches also integrate strategy use and external judgment, such as the Subjective Memory Complaints scale [
21]. Lastly, one-item binary assessments of the presence or absence of subjective complaints are frequently applied, but might lack sensitivity to identify people with high-risk profiles. In contrast, continuous measures enable evaluating metamemory changes over time and investigating associations between subjective judgments and other outcomes. However, many questionnaires lack psychometric assessment, normative data, and appropriate cultural adjustments [
22] and approach metamemory as a singular factor.
The Multifactorial Memory Questionnaire—MMQ [
17] offers a multifactorial approach to SMI or metamemory. It dissociates the scales
Satisfaction,
Ability, and
Strategy, which allows to take differential confounding factors into account.
Dissatisfaction, concerns, or worries about one’s own memory performance, are important predictors for the development of symptomatic Alzheimer’s disease [
5,
10] and conversion to objective cognitive impairment [
23], but are also associated with affective disorders like depression [
24] and confounded by depressiveness [
25]. In contrast, self-rated
ability directly relates to everyday memory function, but is impacted by monitoring ability. Skewed judgments may result from underlying brain pathologies or be biased by the degree of confrontation and self-reflection. Lastly, mnemonic
strategies have a complex relationship to subjective memory ability and satisfaction. While they are frequently applied by high-performing individuals and trained in cognitive interventions [
26‐
28], an increased use of everyday memory strategies is consistently associated with more memory complaints [
29‐
31]. This highlights the potential confounding effect of strategy items in unifactorial questionnaires. Therefore, the additional application time of a multifactorial questionnaire differentiating memory satisfaction, subjective performance, and strategies use can bring significant value by ensuring accurate assessment and facilitating effective treatment planning.
Here, we present the German translation and normative data of the Multifactorial Memory Questionnaire (MMQ [
17]) and (i) provide a culturally and linguistically appropriate transfer, (ii) assess its psychometric properties, and (iii) investigate the differential influence of neuropsychiatric factors including depressiveness, anxiety, sleep, and health-related quality of life on its scales
Satisfaction,
Ability, and
Strategy. Multifactorial metamemory questionnaires have numerous potential applications in research and clinical contexts, including monitoring of longitudinal changes, and evaluating the efficacy and contributing factors of rehabilitation and training interventions. Additionally, they can function as a standardized assessment of self-efficacy and compensatory mechanisms. However, since depressiveness, anxiety, physical and mental health, and sleep differentially affect memory across the life span [
29,
32,
33], neuropsychiatric symptoms need to be considered when evaluating metamemory.
Discussion
In this study, we assessed the German MMQ and its associations with neuropsychiatric factors in a healthy norm sample. First, we translated the original items and instructions considering cultural, linguistic, and conceptual aspects. Second, we assessed the psychometric properties and built normative data for the application of the MMQ in German speakers. The three scales
Satisfaction,
Ability, and
Strategy exhibited a normal distribution, and we observed strong validity, internal consistency, and retest reliability in the German sample. In line with the original MMQ [
17] and other translations of the MMQ [
31], we found no or only small associations of age and gender with the MMQ scales. Furthermore, we found that neuropsychiatric factors such as anxiety, depressiveness, sleep problems, and mental, but not physical health, were associated with the German MMQ scores. Moreover, anxiety, depressiveness, and sleep problems differentially impacted memory satisfaction and self-rated ability across different age groups. Importantly, even subclinical levels of anxiety and depressiveness were associated with significantly reduced
Satisfaction and
Ability MMQ scores.
Concerning the psychometric properties of the German MMQ, the normal distribution of the three scales is advantageous for statistical analyses and enables converting raw scores not only to percentiles, but also to norm scores, like
z-scores [
48]. In addition, we confirmed the German MMQ’s convergent validity in its associations with the CPI, a German questionnaire on subjective cognitive complaints.
Satisfaction and
Ability showed large negative correlations, while
Strategy demonstrated medium-to-large positive associations with the CPI scales memory, attention, and executive complaints. Our findings indicate that higher memory satisfaction and self-reported ability are linked to fewer cognitive complaints, whereas using more memory strategies is correlated with more cognitive complaints. Importantly, associations with the CPI attention and executive scales are reasonable considering the inclusion of some CPI memory items in the attention scale, as well as the overall high item-total correlations and internal consistency of the CPI total score (
α = 0.87) [
19]. Furthermore, several MMQ items require metamemory judgments about everyday memory tasks and prospective memory, where attention and executive functions are essential [
49].
Regarding reliability, we found good (
Strategy) to excellent (
Satisfaction and
Ability) internal consistency. Especially for clinicians, using the reliability to calculate confidence intervals is highly recommended (e.g., Crawford & Garthwaite, 2009). Furthermore, this finding supports the three-scale design for the German MMQ, although evidence suggests a potential division of the
Strategy scale into internal and external strategies with factor analyses supporting both a 3- and 4-factor model of the MMQ [
35,
50]. Thus, interpreting the
Strategy scale as one or two scales is valid, depending on the user’s needs. We provide normative data for both interpretations. Moreover, we found acceptable (
Strategy) to good (
Satisfaction and
Ability) retest reliability, even after an extended retest interval of 8 months. The derived reliable change scores can serve as valuable indicators of clinically relevant changes after an intervention period or during follow-up monitoring.
The multifactorial approach of the MMQ, which recognizes each scale as a separate factor, is a key advantage, allowing for separate interpretation of three dimensions of metamemory [
17]. Although the MMQ scales
Satisfaction and
Ability are strongly associated, they assess different aspects of metamemory, measuring the affective appraisal of memory vs. self-rated frequency of memory mistakes. The finding that increased use of memory strategies correlates with lower self-rated ability and memory satisfaction is in line with MMQ studies in other languages [
29,
31]. Although mnemonic strategies can be relevant in high-demand memory challenges and task-specific strategy use has been related to better performance [
51], MMQ’s strategies are more applicable to everyday situations where healthy individuals typically do not require mnemonic techniques. Thus, an above average strategy use may indicate a subjective need for everyday functioning. However, the
Strategy score can also assist to plan and monitor cognitive interventions in individuals who experience memory impairment and require compensatory strategy use for daily functioning [
52].
In this study, we found minimal associations of the MMQ with demographic factors. Age had a small impact on
Satisfaction and
Ability, while men scored slightly higher on the
Strategy scale than women, with no effect of education on any MMQ scale. Given the small effect sizes, we did not divide the norm tables by age or gender, considering the benefits of a larger norm sample. These findings on the small-to-negligible impact of demographic variables, although in contrast to some findings in metamemory in general [
9], are in line with other MMQ translations [
31,
53,
54].
However, it is important to consider participant age when examining the varying influence of neuropsychiatric factors. Our results show that even subclinical levels of anxiety and depressiveness affect
Satisfaction and
Ability scores and anxiety impacted young and older but not middle-aged adults, consistent with prior research on SMI and affective symptoms in elderly people [
55,
56]. Moreover, depressiveness most strongly and robustly affected memory satisfaction, likely due to depression-associated worries, negative self-beliefs and aging stereotypes [
19,
57], and strong overlap of some
Satisfaction items with affective symptoms (e.g., MMQ Satisfaction: “I feel unhappy when I think about my memory ability.”). Anxiety might lower self-rated ability and memory satisfaction through increased uncertainty intolerance and health monitoring [
58]. Sleep problems may disproportionately impact
Satisfaction and
Ability in middle-aged adults due to increased time and cognitive demands by family and work responsibilities. This results in diminished sleep duration and greater functional impairment compared to older and frequently retired individuals [
59], where total sleeping time was not associated with cognitive performance [
60]. These findings highlight that depressiveness, anxiety, and sleep quality should be assessed and considered along with participants’ age, even when clinical cutoffs are not met, and advocate for a multifactorial approach toward metamemory.
It is important to note that the multifactorial approach of the MMQ also has drawbacks, including extended assessment time and the lack of an integrated single metamemory score. A limiting factor in our study is the online assessment lacking an objective marker of cognitive impairment. Despite a rigorous exclusion process to mitigate their impact, participants with cognitive impairment may remain in the sample. Ongoing studies will scrutinize the German MMQ’s onsite validity and assess its sensitivity in different pathologies and predictive value for patients’ quality of life. Furthermore, participants with lower educational background and with an age above 82 years are underrepresented in the current normative sample, warranting future studies with geriatric participants. Lastly, longer retest intervals, while common for follow-up visits, may have introduced bias, since not all participants could be reassessed.
Although subjective judgment about one’s own memory ability has repeatedly been shown to have small or no associations with objectified memory performance in standardized tests (e.g., Burmester et al. [
61]), metamemory offers a distinct advantage over standardized memory assessments through its reflection of individual challenges [
17]. Furthermore, it is sensitive to declines in personal performance, even in high-performing and mildly affected patients, where comparison to normative data might fall short. Consequently, the MMQ holds considerable value for clinical diagnosis and cognitive rehabilitation, where the goal is to regain adequate functionality within an individual’s environment [
52,
62].
Taken together, our study indicates that the German MMQ scales show normal distribution, are valid and reliable, and provides normative data that can be useful to detect subjective memory impairment and monitor metamemory. Specifically, the MMQ scales Satisfaction and Ability sensitively reflect individual everyday memory problems, while the Strategy scale can be used to plan and monitor strategy applications and promote functional adaptation, for instance in cognitive interventions. The MMQ scales can be applied separately and easily integrated into clinical and research settings, particularly by employing a tablet or computerized version with automated scoring. In addition, the reliable change scores provide helpful measures for follow-up and therapy evaluation. This way, the German MMQ provides a sensitive assessment of metamemory as a personalized measures of functionality in acute care hospital, rehabilitation settings, observational studies, and clinical trials.