Prevention of depression and sleep disturbances in elderly with memory-problems by activation of the biological clock with light - a randomized clinical trial

<p>Abstract</p> <p>Background</p> <p>Depression frequently occurs in the elderly and in patients suffering from dementia. Its cause is largely unknown, but several studies point to a possible contribution of circadian rhythm disturbances. Post-mortem studies on aging, dementia and depression show impaired functioning of the suprachiasmatic nucleus (SCN) which is thought to be involved in the increased prevalence of day-night rhythm perturbations in these conditions. Bright light enhances neuronal activity in the SCN. Bright light therapy has beneficial effects on rhythms and mood in institutionalized moderate to advanced demented elderly. In spite of the fact that this is a potentially safe and inexpensive treatment option, no previous clinical trial evaluated the use of long-term daily light therapy to prevent worsening of sleep-wake rhythms and depressive symptoms in early to moderately demented home-dwelling elderly.</p> <p>Methods/Design</p> <p>This study investigates whether long-term daily bright light prevents worsening of sleep-wake rhythms and depressive symptoms in elderly people with memory complaints. Patients with early Alzheimer's Disease (AD), Mild Cognitive Impairment (MCI) and Subjective Memory Complaints (SMC), between the ages of 50 and 75, are included in a randomized double-blind placebo-controlled trial. For the duration of two years, patients are exposed to ~10,000 lux in the active condition or ~300 lux in the placebo condition, daily, for two half-hour sessions at fixed times in the morning and evening. Neuropsychological, behavioral, physiological and endocrine measures are assessed at baseline and follow-up every five to six months.</p> <p>Discussion</p> <p>If bright light therapy attenuates the worsening of sleep-wake rhythms and depressive symptoms, it will provide a measure that is easy to implement in the homes of elderly people with memory complaints, to complement treatments with cholinesterase inhibitors, sleep medication or anti-depressants or as a stand-alone treatment.</p> <p>Trial registration</p> <p>ISRCTN29863753</p

Psychometric Properties of the Parent and Teacher Versions of the Strengths and Difficulties Questionnaire for 4- to 12-Year-Olds: A Review

Since its development, the Strengths and Difficulties Questionnaire (SDQ) has been widely used in both research and practice. The SDQ screens for positive and negative psychological attributes. This review aims to provide an overview of the psychometric properties of the SDQ for 4- to 12-year-olds. Results from 48 studies (N = 131,223) on reliability and validity of the parent and teacher SDQ are summarized quantitatively and descriptively. Internal consistency, test–retest reliability, and inter-rater agreement are satisfactory for the parent and teacher versions. At subscale level, the reliability of the teacher version seemed stronger compared to that of the parent version. Concerning validity, 15 out of 18 studies confirmed the five-factor structure. Correlations with other measures of psychopathology as well as the screening ability of the SDQ are sufficient. This review shows that the psychometric properties of the SDQ are strong, particularly for the teacher version. For practice, this implies that the use of the SDQ as a screening instrument should be continued. Longitudinal research studies should investigate predictive validity. For both practice and research, we emphasize the use of a multi-informant approach

Synthesis and structure determination from an extremely small crystal of a new layered gallium phosphate

A new layered gallium phosphate material [(GaPO4)(4)(OH)F.2(C7H11N2)], DMAP-GaPO, has been prepared using 4-dimethylaminopyridine as a structure directing agent (SDA) in the presence of fluorine. The material consists of layers of a zeolite related fluorinated gallium phosphate separated by the SDA. The structure was solved from single crystal X-ray diffraction data collected from an extremely small crystal using synchrotron radiation. The gallophosphate layer consists of a novel type of secondary building unit (SBU) which is related to the double four ring (D4R) cage, one of the most common motifs in gallium phosphate open framework structures. We propose that this unit could be produced by the isomerisation of a D4R prenucleation building unit (PNBU) on condensation. (C) 2001 Elsevier Science Ltd. All rights reserved.</p

The synthesis of gallium phosphte frameworks with and without fluoride ions present: attempts to direct the synthesis of double four ring-containing materials

During attempts to synthesise gallium phosphate materials containing the double four-ring building unit, three pyridine-templated gallium fluorophosphates and one pyridine-templated gallium phosphate were prepared and their structures solved using single crystal X-ray diffraction experiments. None of the three fluorophosphates contained the double four-ring unit, while the material prepared in the absence of fluoride did. This overturns some of the conventional wisdom that fluoride is necessary to specifically form the double four-ring unit. The synthetic conditions needed to prepare the materials and possible relationships between the building units found in the solids are discussed.</p