Detection of subthreshold depression and subthreshold anxiety in the elderly

OBJECTIVE: To assess the ability of screening instruments to detect subthreshold depression or subthreshold anxiety and to make suggestions for the improvement of instrument performance. DESIGN: Group definition relied on the presence or absence of major psychiatric disorders or of subthreshold disorders (Composite International Diagnostic Interview). SETTING: A community-based study in Germany. PARTICIPANTS: The total sample comprised 274 subjects over 60 years of age; 57 subjects suffered from acute subthreshold depression, 26 subjects suffered from acute subthreshold anxiety, 173 subjects were defined as being healthy (i.e. no acute or lifetime major psychiatric disorder, no acute subthreshold disorder). MEASURES: The short version of the General Health Questionnaire (GHQ-12), the Center for Epidemiologic Studies--Depression Scale (CES-D), the Structured Interview for the Diagnosis of Dementia of the Alzheimer-type, Multiinfarct Dementia and Dementias of other Etiology (SIDAM) for cognitive impairment. RESULTS: Subjects with subthreshold disorders scored higher on the CES-D and the GHQ-12 than healthy individuals. The most distinct increase was observed in the CES-D score of subjects with subthreshold anxiety. The CES-D factor for the presence of somatic/vegetative symptoms performed slightly better compared to the other CES-D factors. CONCLUSIONS: The CES-D moderately detected subthreshold anxiety. Subthreshold depression could not be efficiently detected by either questionnaire. The combination of items indicating the presence of somatic symptoms and depressive affect could improve instrument performance when screening for subthreshold anxiety but not for subthreshold depression.