David A. Richards

Learn More
We have identified and characterized two vesicle recycling pathways in frog motor nerve terminals. We exploited the differential staining properties of FM dyes of varying hydrophobicity to label selectively two different vesicle pools, using optical imaging and electron microscopy of photoconverted dyes. During a 1 min tetanus, a rapidly recycling route(More)
BACKGROUND The relative efficacy of different psychological treatments for chronic post-traumatic stress disorder (PTSD) is unclear. AIMS To determine the efficacy of specific psychological treatments for chronic PTSD. METHOD In a systematic review of randomised controlled trials, eligible studies were assessed against methodological quality criteria(More)
BACKGROUND Common mental health problems, such as depression and anxiety, are estimated to affect up to 15% of the UK population at any one time, and health care systems worldwide need to implement interventions to reduce the impact and burden of these conditions. Collaborative care is a complex intervention based on chronic disease management models that(More)
BACKGROUND Although self-help interventions are effective in treating depression, less is known about the factors that determine effectiveness (i.e. moderators of effect). This study sought to determine whether the content of self-help interventions, the study populations or aspects of study design were the most important moderators. METHOD Randomized(More)
To summarize the psychometric properties of the PHQ2 and PHQ9 as screening instruments for depression. We identified 17 validation studies conducted in primary care; medical outpatients; and specialist medical services (cardiology, gynecology, stroke, dermatology, head injury, and otolaryngology). Electronic databases from 1994 to February 2007 (MEDLINE,(More)
BACKGROUND Depression is common in primary care but is suboptimally managed. Collaborative care, that is, structured care involving a greater role of nonmedical specialists to augment primary care, has emerged as a potentially effective candidate intervention to improve quality of primary care and patient outcomes. METHODS To quantify the short-term and(More)
We have characterized the morphological and functional properties of the readily releasable pool (RRP) and the reserve pool of synaptic vesicles in frog motor nerve terminals using fluorescence microscopy, electron microscopy, and electrophysiology. At rest, about 20% of vesicles reside in the RRP, which is depleted in about 10 s by high-frequency nerve(More)
Recently the UK Government announced an unprecedented, large-scale initiative for Improving Access to Psychological Therapies (IAPT) for depression and anxiety disorders. Prior to this development, the Department of Health established two pilot projects that aimed to collect valuable information to inform the national roll-out. Doncaster and Newham received(More)
We have examined the kinetics by which FM1-43 escapes from individual synaptic vesicles during exocytosis at hippocampal boutons. Two populations of exocytic events were observed; small amplitude events that lose dye slowly, which made up more than half of all events, and faster, larger amplitude events with a fluorescence intensity equivalent to single(More)
Synaptic plasticity at neuronal connections has been well characterized functionally by using electrophysiological approaches, but the structural basis for this phenomenon remains controversial. We have studied the dynamic interactions between presynaptic and postsynaptic structures labeled with FM 4-64 and a membrane-targeted GFP, respectively, in(More)