Simvastatin is being employed because it is a 'statin'. As a drug class, statins have broad
anti-inflammatory properties. Low-level inflammation is thought to be a potentially important
mediator of the effects of psychosocial stress (including loneliness) on affect and
vulnerability to depression. In this study we are using statins as an experimental tool to
investigate this relationship further. Statins are widely prescribed agents that are regarded
as very safe and so are suitable tools in this context. We have selected simvastatin because
it is one of the most widely used statins and has an excellent safety profile, being also
available 'over the counter'.