Despite being commonly used in research and clinical practice, the evidence regarding the factor structure of the Beck Depression Inventory-II (BDI-II) remains equivocal and this has implications on how the scale scores should be aggregated. Researchers continue to debate whether the BDI-II is best viewed as a unidimensional scale, or whether specific subscales have utility. The present study sought to test a comprehensive range of competing factor analytic models of the BDI-II, including traditional non-hierarchical multidimensional models and confirmatory bifactor models.

Participants (n=370) were clinical outpatients diagnosed with either depressive episode or adjustment disorder. Confirmatory factor analysis and confirmatory bifactor modelling were used to test 15 competing models. The unidimensionality of the best fitting model was assessed using three strength indices (explained common variance, percentage of uncontaminated correlations and ω hierarchical).

Overall, bifactor solutions provided superior fit than both unidimensional and non-hierarchical multidimensional models. The best fitting model consisted of a general depression factor and three specific factors: cognitive, somatic and affective. High factor loadings and strength indices for the general depression factor supported the view that the BDI-II measures a single latent construct.

The BDI-II should primarily be viewed as a unidimensional scale, and should be scored as such. Although it is not recommended that scores on individual subscales are used in isolation, they may prove useful in clinical assessment and/or treatment planning if used in conjunction with total scores.

The National Psychiatric Morbidity Survey (NPMS) programme was partly designed to monitor trends in mental disorders, including depression, with comparable data spanning 1993 to 2007. Findings already published from this programme suggest that concerns about increasing prevalence of common mental disorders (CMDs) may be unfounded. This article focuses on depression and tests the hypothesis that successive birth cohorts experience the same prevalence of depression as they age.

We carried out a pseudo-cohort analysis of a sequence of three cross-sectional surveys of the English household population using identical diagnostic instruments. The main outcome was ICD-10 depressive episode or disorder. Secondary outcomes were the depression subscales of the Clinical Interview Schedule – Revised (CIS-R).

There were 8670, 6977 and 6815 participants in 1993, 2000 and 2007 respectively. In men, the prevalence of depression increased between cohorts born in 1943–1949 and 1950–1956 [odds ratio (OR) 2.5, 95% confidence interval (CI) 1.4–4.2], then remained relatively stable across subsequent cohorts. In women, there was limited evidence of change in prevalence of depression. Women born in 1957–1963, surveyed aged 44–50 years in 2007, had exceptionally high prevalence. It is not clear whether this represents a trend or a quirk of sampling.

There is no evidence of an increase in the prevalence of depression in male cohorts born since 1950. In women, there is limited evidence of increased prevalence. Demand for mental health services may stabilize or even fall for men.

The impact of different levels of depression severity on quality of life (QoL) is not well studied, particularly regarding ICD-10 criteria. The ICD classification of depressive episodes in three levels of severity is also controversial and the less severe category, mild, has been considered as unnecessary and not clearly distinguishable from non-clinical states. The present work aimed to test the relationship between depression severity according to ICD-10 criteria and several dimensions of functioning as assessed by Medical Outcome Study (MOS) 36-item Short Form general health survey (SF-36) at the population level.

A sample of 551 participants from the second phase of the Outcome of Depression International Network (ODIN) study (228 controls without depression and 313 persons fulfilling ICD criteria for depressive episode) was selected for a further assessment of several variables, including QoL related to physical and mental health as measured with the SF-36.

Statistically significant differences between controls and the depression group were found in both physical and mental markers of health, regardless of the level of depression severity; however, there were very few differences in QoL between levels of depression as defined by ICD-10. Regardless of the presence of depression, disability, widowed status, being a woman and older age were associated with worse QoL in a structural equation analysis with covariates. Likewise, there were no differences according to the type of depression (single-episode versus recurrent).

These results cast doubt on the adequacy of the current ICD classification of depression in three levels of severity.

Diagnostic criteria and empirical evidence support the existence of cognitive deficits in depression. However, depressed mood, loss of interest and low self-efficacy might influence cognitive performance.

Goal-setting instructions were used to promote motivation in depressed patients and control subjects during neuropsychological assessment. The resulting performance was compared with performance using standard instructions. Sixty in-patients with non-psychotic unipolar depression and 60 age- and education-matched healthy control subjects were assessed with standard neuropsychological tests [the Auditory Verbal Learning Test (AVLT), the Digit Symbol Test (DST), the Regensburg Word Fluency Test (RWT), and the Number Combination Test (Zahlen-Verbindungs-Test, ZVT)] using either goal-setting or standard test instructions.

Depressed patients showed lower baseline performance and lower generalized self-efficacy (p<0.0005) than controls. However, goal-setting instructions significantly improved patients' memory performance by 10% [AVLT: F(5, 54)=3.611, p=0.007] and psychomotor performance by 13% [ZVT: F(3, 56)=3.667, p=0.017]. Consequently, patients and control subjects demonstrated similar results when goal-setting instructions were applied. Goal-setting instructions showed a statistical trend, increasing patients' performance in the DST by 12% [F(1, 58)=2.990, p=0.089], although their verbal fluency measured by the RWT did not increase. No significant correlations of increased performance with generalized self-efficacy were found.

Cognitive deficits in depressed patients are influenced by motivational shortcomings. Because generalized self-efficacy failed to correlate to increased test performance, future research needs to disentangle the effective components of goal-setting instructions. Task-specific self-efficacy as well as enhancement of task-focused attention might underlie the significant goal-setting effect in depressed patients.