Julie D. Henry

The short-form version of the Depression Anxiety Stress Scales (DASS-21): Construct validity and normative data in a large non-clinical sample

OBJECTIVES To test the construct validity of the short-form version of the Depression anxiety and stress scale (DASS-21), and in particular, to assess whether stress as indexed by this measure is synonymous with negative affectivity (NA) or whether it represents a related, but distinct, construct. To provide normative data for the general adult population. DESIGN Cross-sectional, correlational and confirmatory factor analysis (CFA). METHODS The DASS-21 was administered to a non-clinical sample, broadly representative of the general adult UK population (N = 1,794). Competing models of the latent structure of the DASS-21 were evaluated using CFA. RESULTS The model with optimal fit (RCFI = 0.94) had a quadripartite structure, and consisted of a general factor of psychological distress plus orthogonal specific factors of depression, anxiety, and stress. This model was a significantly better fit than a competing model that tested the possibility that the Stress scale simply measures NA. CONCLUSIONS The DASS-21 subscales can validly be used to measure the dimensions of depression, anxiety, and stress. However, each of these subscales also taps a more general dimension of psychological distress or NA. The utility of the measure is enhanced by the provision of normative data based on a large sample.

The positive and negative affect schedule (PANAS): construct validity, measurement properties and normative data in a large non-clinical sample.

OBJECTIVES To evaluate the reliability and validity of the PANAS (Watson, Clark, & Tellegen, 1988b) and provide normative data. DESIGN Cross-sectional and correlational. METHOD The PANAS was administered to a non-clinical sample, broadly representative of the general adult UK population (N = 1,003). Competing models of the latent structure of the PANAS were evaluated using confirmatory factor analysis. Regression and correlational analysis were used to determine the influence of demographic variables on PANAS scores as well as the relationship between the PANAS with measures of depression and anxiety (the HADS and the DASS). RESULTS The best-fitting model (robust comparative fit index = .94) of the latent structure of the PANAS consisted of two correlated factors corresponding to the PA and NA scales, and permitted correlated error between items drawn from the same mood subcategories (Zevon & Tellegen, 1982). Demographic variables had only very modest influences on PANAS scores and the PANAS exhibited measurement invariance across demographic subgroups. The reliability of the PANAS was high, and the pattern of relationships between the PANAS and the DASS and HADS were consistent with tripartite theory. CONCLUSION The PANAS is a reliable and valid measure of the constructs it was intended to assess, although the hypothesis of complete independence between PA and NA must be rejected. The utility of this measure is enhanced by the provision of large-scale normative data.

The Depression Anxiety Stress Scales (DASS): Normative data and latent structure in a large non-clinical sample

OBJECTIVES To provide UK normative data for the Depression Anxiety and Stress Scale (DASS) and test its convergent, discriminant and construct validity. DESIGN Cross-sectional, correlational and confirmatory factor analysis (CFA). METHODS The DASS was administered to a non-clinical sample, broadly representative of the general adult UK population (N = 1,771) in terms of demographic variables. Competing models of the latent structure of the DASS were derived from theoretical and empirical sources and evaluated using confirmatory factor analysis. Correlational analysis was used to determine the influence of demographic variables on DASS scores. The convergent and discriminant validity of the measure was examined through correlating the measure with two other measures of depression and anxiety (the HADS and the sAD), and a measure of positive and negative affectivity (the PANAS). RESULTS The best fitting model (CFI =.93) of the latent structure of the DASS consisted of three correlated factors corresponding to the depression, anxiety and stress scales with correlated error permitted between items comprising the DASS subscales. Demographic variables had only very modest influences on DASS scores. The reliability of the DASS was excellent, and the measure possessed adequate convergent and discriminant validity Conclusions: The DASS is a reliable and valid measure of the constructs it was intended to assess. The utility of this measure for UK clinicians is enhanced by the provision of large sample normative data.

Normative data for the HADS from a large non-clinical sample.

OBJECTIVES To provide normative data for the Hospital Anxiety Depression Scale (HADS). DESIGN Repeated measures and correlational. METHODS The HADS was administered to a non-clinical sample, broadly representative of the general adult UK population (N = 1792) in terms of the distributions of age, gender and occupational status. Correlational analysis was used to determine the influence of demographic variables on HADS scores. RESULTS Demographic variables had only very modest influences on HADS scores. The reliability of the HADS is acceptable; the Anxiety and Depression scales are moderately correlated (.53). Tables to convert raw scores to percentiles are presented for females and males. CONCLUSIONS The present normative data allow clinicians to assess the rarity of a given HADS score, and thus provide a useful supplement to existing cut-off scores.

A meta-analytic review of emotion recognition and aging: Implications for neuropsychological models of aging

This meta-analysis of 28 data sets (N=705 older adults, N=962 younger adults) examined age differences in emotion recognition across four modalities: faces, voices, bodies/contexts, and matching of faces to voices. The results indicate that older adults have increased difficulty recognising at least some of the basic emotions (anger, sadness, fear, disgust, surprise, happiness) in each modality, with some emotions (anger and sadness) and some modalities (face-voice matching) creating particular difficulties. The predominant pattern across all emotions and modalities was of age-related decline with the exception that there was a trend for older adults to be better than young adults at recognising disgusted facial expressions. These age-related changes are examined in the context of three theoretical perspectives-positivity effects, general cognitive decline, and more specific neuropsychological change in the social brain. We argue that the pattern of age-related change observed is most consistent with a neuropsychological model of adult aging stemming from changes in frontal and temporal volume, and/or changes in neurotransmitters.

A Meta-Analytic Review of Verbal Fluency Performance Following Focal Cortical Lesions

A meta-analysis of 31 studies with 1,791 participants was conducted to investigate the sensitivity of tests of verbal fluency to the presence of focal cortical lesions. Relative to healthy controls, participants with focal frontal injuries had large and comparable deficits on phonemic (r = .52) and semantic (r = .54) fluency. For frontal but not nonfrontal patients, phonemic fluency deficits qualified as differential deficits when compared with IQ and psychomotor speed; phonemic fluency was also more strongly and more specifically related to the presence of frontal lesions than the Wisconsin Card Sorting Test scores. In contrast, temporal damage was associated with a lesser deficit on phonemic fluency (r = .44) but a larger deficit on semantic fluency (r = .61).

A Meta-Analytic Review of Prospective Memory and Aging.

A meta-analysis of prospective memory (PM) studies revealed that in laboratory settings younger participants outperform older participants on tests of both time- and event-based PM (rs=-.39 and -.34, respectively). Event-based PM tasks that impose higher levels of controlled strategic demand are associated with significantly larger age effects than event-based PM tasks that are supported by relatively more automatic processes (rs=-.40 vs. -.14, respectively). However, contrary to the prevailing view in the literature, retrospective memory as measured by free recall is associated with significantly greater age-related decline (r=-.52) than PM, and older participants perform substantially better than their younger counterparts in naturalistic PM studies (rs=.35 and.52 for event- and time-based PM, respectively).

Verbal fluency performance in dementia of the Alzheimer’s type: A meta-analysis

A meta-analysis of 153 studies with 15,990 participants was conducted to compare the magnitude of deficits upon tests of phonemic and semantic fluency for patients with dementia of the Alzheimers type (DAT) relative to healthy controls. As has been found for patients with focal temporal cortical lesions (but not for patients with focal frontal cortical lesions), DAT patients were significantly more impaired on tests of semantic relative to phonemic fluency (r=0.73 and 0.57, respectively). Thus, since phonemic and semantic fluency are considered to impose comparable demands upon executive control processes such as effortful retrieval, but the latter is relatively more dependent upon the integrity of semantic memory, these results suggest that the semantic memory deficit in DAT reflects a degradation of the semantic store. Also supporting this conclusion, confrontation naming, a measure of semantic memory that imposes only minimal demands upon effortful retrieval, was significantly more impaired than phonemic fluency (r=0.60 versus 0.55, respectively). However, since semantic fluency was also significantly more impaired than confrontation naming (r=0.73 versus 0.61), deficits in semantic memory and effortful retrieval may be additive. Semantic, but not phonemic fluency, was significantly more impaired than measures of verbal intelligence and psychomotor speed. Thus, the semantic memory deficit in DAT qualifies as a differential deficit, but executive dysfunction as indexed by phonemic fluency does not constitute an additional isolated feature of the disorder. Dementia severity was not significantly related to the relative magnitude of deficits upon phonemic and semantic fluency.

Verbal fluency deficits in Parkinson's disease: A meta-analysis

A meta-analysis of 68 studies with a total of 4644 participants was conducted to investigate the sensitivity of tests of verbal fluency to the presence of Parkinsons disease (PD) relative to healthy controls. Both phonemic and semantic fluency were moderately impaired but neither deficit qualified as a differential deficit relative to verbal intelligence or psychomotor speed. However, PD patients were significantly more impaired on semantic relative to phonemic fluency (rs =.37 vs.33, respectively), and confrontation naming, a test of semantic memory that imposes only minimal demands upon cognitive speed and effortful retrieval, was associated with a deficit that was of a comparable magnitude to the deficits upon each of these types of fluency. Thus, the disorder appears to be associated with particular problems with semantic memory. Tests that impose heavy demands upon switching may also be disproportionately affected. Demented and non-demented PD patients differ quantitatively but not qualitatively in terms of the relative prominence of deficits on tests of phonemic and semantic fluency. However, patients with dementia of the Alzheimers type and demented PD patients can be differentiated from one another by the relative magnitude of deficits upon these two measures.

A meta-analytic review of verbal fluency deficits in schizophrenia relative to other neurocognitive deficits

Introduction. A prominent view in the neuropsychological literature is that schizophrenia is particularly associated with executive dysfunction, yet in a meta-analytic review it was concluded that, relative to their general level of intellectual functioning, schizophrenics are not disproportionately impaired on a measure of this construct, the Wisconsin Card Sorting Test (WCST). However, verbal fluency tests may be more valid measures of executive functioning as they are more sensitive to the presence of focal frontal lobe injuries.Method. A meta-analysis was conducted on 84 studies comparing the performance of schizophrenics and healthy controls on tests of phonemic and semantic fluency, as well as other cognitive measures presumed to impose only minimal demands on executive functioning.Results. Neither phonemic or semantic fluency deficits qualified as differential deficits relative to general intelligence or psychomotor speed. Patients with schizophrenia were significantly more impaired on semantic relative to phonemic fluency.Conclusions. As for the WCST, deficits on tests of verbal fluency reflect a more generalised intellectual impairment and not particular difficulties with executive control processes. The larger deficit for semantic relative to phonemic fluency suggests that, in addition to general retrieval difficulties, schizophrenia is associated with compromises to the semantic store.