L-theanine for improving focused attention and sleep quality, while reducing stress and anxiety

Although the evidence is not a slam dunk home run, if I can mix sporting metaphors, research suggests that taking L-theanine derived from green tea at a dose of 200-400mg daily has the power to alleviate anxiety, reduce stress and depression, improve focus and attention, and benefit sleep quality, all without the downside of increased drowsiness, a side effect of taking valium, a drug often used to treat anxiety.  Taking extra B vitamins might also help to accentuate these benefits.