Screening for depression in high-risk groups: prospective cohort study in general practice.

BACKGROUND: Currently only about half of the people who have major depressive disorder are detected during regular health care. Screening in high-risk groups might be a possible solution. AIMS: To evaluate the effectiveness of selective screening for major depressive disorder in three high-risk groups in primary care: people with mental health problems, people with unexplained somatic complaints and people who frequently attend their general practitioner. METHOD: Prospective cohort study among 2005 people in high-risk groups in three health centres in The Netherlands. RESULTS: Of the 2005 people identified, 1687 were invited for screening and of these 780 participated. Screening disclosed 71 people with major depressive disorder: 36 (50.7%) already received treatment, 14 (19.7%) refused treatment and 4 individuals did not show up for an appointment. As a final result of the screening, 17 individuals (1% of 1687) started treatment for major depressive disorder. CONCLUSIONS: Screening for depression in high-risk populations does not seem to be effective, mainly because of the low rates of treatment initiation, even if treatment is freely and easily accessible.

Measurement invariance with respect to ethnicity of the Patient Health Questionnaire-9 (PHQ-9).

BACKGROUND: The Patient Health Questionnaire-9 (PHQ-9) has been widely used in research and clinical settings. To be able to attribute differences in PHQ-9 scores between groups with different cultural backgrounds to differences in the level of depression, the instrument has to possess measurement invariance. METHODS: Data from the Apollo-D study were used. We used two strongly contrasting cultural groups (n=1772). Measurement invariance was assessed by comparing four categorical single factor models with an increasing number of restrictions, representing an increasingly stronger measurement invariance assumption. RESULTS: The PHQ-9 was measurement invariant for ethnicity in women and partially measurement invariant for ethnicity in men. The item 'psychomotor problems' seemed to be culturally biased in the Surinam Dutch males. It had a higher loading and threshold compared to Dutch males. LIMITATIONS: The sample is restricted to high risk primary care patients, we did not include a gold standard measure of depression and the analyses pertain to a single cross cultural comparison. CONCLUSIONS: The observed higher total depression score for females in the Surinam Dutch group can be attributed to a true difference in the latent trait depression. For Surinam Dutch and Dutch men some caution is warranted when comparing results obtained with the PHQ-9. In the former group the scores may be biased slightly downward. Future research is needed to examine how the item 'psychomotor problems' performs in different populations. These findings highlight the necessity of establishing measurement invariance before drawing conclusions based on observed scores.

Brief cognitive behavioral therapy compared to general practitioners care for depression in primary care: a randomized trial.

BACKGROUND: Depressive disorders are highly prevalent in primary care (PC) and are associated with considerable functional impairment and increased health care use. Research has shown that many patients prefer psychological treatments to pharmacotherapy, however, it remains unclear which treatment is most optimal for depressive patients in primary care. METHODS/DESIGN: A randomized, multi-centre trial involving two intervention groups: one receiving brief cognitive behavioral therapy and the other receiving general practitioner care. General practitioners from 109 General Practices in Nijmegen and Amsterdam (The Netherlands) will be asked to include patients aged between 18-70 years presenting with depressive symptomatology, who do not receive an active treatment for their depressive complaints. Patients will be telephonically assessed with the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) to ascertain study eligibility. Eligible patients will be randomized to one of two treatment conditions: either 8 sessions of cognitive behavioral therapy by a first line psychologist or general practitioner's care according to The Dutch College of General Practitioners Practice Guideline (NHG- standard). Baseline and follow-up assessments are scheduled at 0, 6, 12 and 52 weeks following the start of the intervention. Primary outcome will be measured with the Hamilton Depression Rating Scale-17 (HDRS-17) and the Patient Health Questionnaire-9 (PHQ-9). Outcomes will be analyzed on an intention to treat basis. TRIAL REGISTRATION: ISRCTN65811640.

Estimating non-response bias in family studies: application to mental health and lifestyle.

Non-response to mailed surveys reduces the effective sample size and may introduce bias. Non-response has been studied by (1) comparison to available data in population based registers, (2) directly contacting non-respondents by telephone or single-item reply cards, and (3) longitudinal repetition of the survey. The goal of this paper was to propose an additional method to study non-response bias: when the variable of interest has a familial component, data from respondents can be used as proxy for the data from their non-responding family members. This approach was used with data on smoking, alcohol consumption, physical activity, coffee- and tea-use, education, body mass index, religion, burnout, life events, personality and mental health in large number of siblings and DZ twins registered with the Netherlands Twin Register. In addition, for smoking behavior, we also used the second strategy by sending a reply card. Results show that scores of members from less cooperative families or incomplete twin pairs tended to be more unfavorable than the scores from highly cooperative families or complete twin pairs. For example, family members from less cooperative families cycled less often and scored higher on anxious depression and neuroticism. For smoking, both the results of the reply card and the results of the additional method suggested a higher percentage smokers among the non-respondents but this was only significant with reply card method. In general, differences between highly/less cooperative families and complete/incomplete DZ twins were small. Results suggest that, even for studies with moderate response rates, data collected on health, personality and lifestyle are relatively unbiased.