General practitioners' conceptions about treatment of depression and factors that may influence their practice in this area. A postal survey

BACKGROUND: The way GPs work does not appear to be adapted to the needs of depressive patients. Therefore we wanted to examine Swedish GPs' conceptions of depressive disorders and their treatment and GPs' ideas of factors that may influence their manner of work with depressive patients. METHODS: A postal questionnaire to a stratified sample of 617 Swedish GPs. RESULTS: Most respondents assumed antidepressive drugs effective and did not assume that psychotherapy can replace drugs in depression treatment though many of them looked at psychotherapy as an essential complement. Nearly all respondents thought that clinical experiences had great importance in decision situations, but patients' own preferences and official clinical guidelines were also regarded as essential. As influences on their work, almost all surveyed GPs regarded experiences from general practice very important, and a majority also emphasised experiences from private life. Courses arranged by pharmaceutical companies were seen as essential sources of knowledge. A majority thought that psychiatrists did not provide sufficient help, while most respondents perceived they were well backed up by colleagues. CONCLUSION: GPs tend to emphasize experiences, both from clinical work and private life, and overlook influences of collegial dealings and ongoing CME as well as the effects of the pharmaceutical companies' marketing activities. Many GPs appear to need more evidence based knowledge about depressive disorders. Interventions to improve depression management have to be supporting and interactive, and should be combined with organisational reforms to improve co-operation with psychiatrists

High-frequency response of atomic-force microscope cantilevers

Recent advances in atomic-force microscopy have moved beyond the original quasistatic implementation into a fully dynamic regime in which the atomic-force microscope cantilever is in contact with an insonified sample. The resulting dynamical system is complex and highly nonlinear. Simplification of this problem is often realized by modeling the cantilever as a one degree of freedom system. This type of first-mode approximation (FMA), or point-mass model, has been successful in advancing material property measurement techniques. The limits and validity of such an approximation have not, however, been fully addressed. In this article, the complete flexural beam equation is examined and compared directly with the FMA using both linear and nonlinear examples. These comparisons are made using analytical and finite difference numerical techniques. The two systems are shown to have differences in drive-point impedance and are influenced differently by the interaction damping. It is shown that the higher modes must be included for excitations above the first resonance if both the low and high frequency dynamics are to be modeled accurately