L-theanine is an amino acid that occurs naturally in tea leaves and is used in Asian medicine to treat many medical and mental health problems. In a previous blog post I briefly reviewed the evidence for l-theanine for stress and anxiety reduction. In this post I add to the discussion on l-theanine by reviewing important recent findings on l-theanine for a variety of mental health problems. Findings of animal and human research support that taking l-theanine on a regular basis improves cognitive performance, attention, sleep quality, and may enhance mood, and reduce symptoms of OCD, panic disorder and bipolar disorder. L-theanine also has important general health benefits including reduction of the risk of cardiovascular disease and fighting obesity (Türközü 2017).
Beneficial effects achieved through multiple mechanisms of action
L-theanine increases brain levels of serotonin, GABA and dopamine, binds to excitatory neurotransmitter receptors (i.e., glutamate and NMDA), and may increase levels of brain-derived neurotrophic factor (BDNF). Taking l-theanine on a regular daily basis for 3 to 4 weeks may confer general neuroprotective benefits by increasing synthesis of brain-derived neurotrophic factor. The stress reducing and cognitive enhancing benefits of l-theanine are probably related to its role in oxidative damage caused by ‘free radicals.’ Collectively, these effects are believed to result in anxiety reduction and the other beneficial effects of l-theanine on mental health.
Findings of animal and human studies have established that l-theanine improves learning, memory and cognitive function, and enhances selective attention during challenging mental tasks. In addition to its well-known benefits for reducing stress, regular consumption of tea made from the leaves of Camellia sinensis, may have therapeutic effects on a range of mental health problems. Examples include reducing the rate of cognitive decline in healthy aging, improving general mood, reducing the severity of depressed mood (Hidese 2017), attention deficit disorder (ADD), panic disorder, obsessive compulsive disorder (OCD), and bipolar disorder (Lardner 2014). L-theanine may also provide a promising add-on therapy to antipsychotics in individuals diagnosed with schizophrenia (Kardashev 2018).
Most people who take l-theanine at doses between 50 and 200mg report a general calming effect within 30 to 40 minutes which may last 8 to 10 hours. Taking l-theanine at a dosage of 200mg once or twice daily is an appropriate dosage for moderately severe anxiety. For more severe anxiety symptoms total daily doses up to 600mg to 800mg are sometimes needed. In this case, l-theanine is best taken in increments of 100mg to 200mg spaced over the day.
No serious safety concerns
Unlike sedative-hypnotics and other anti-anxiety medications, l-theanine does not cause drowsiness, slow reflexes or impair concentration and there is no risk of developing dependence. L-theanine does not interact with other natural supplements or medications and may be safely taken in combination with psychotropic medications potentially improving their effectiveness.
In addition to established stress- and anxiety-reducing benefits of l-theanine, emerging research findings show that this naturally occurring amino acid has many important beneficial effects on health and brain function including reduced risk of cardiovascular disease and reduced obesity. Emerging findings of animal and human research studies support that the mental health benefits of l-theanine include enhanced cognitive performance, improved attention, decreased anxiety, and possibly also beneficial effects when used as an adjunctive treatment of obsessive-compulsive disorder (OCD) and schizophrenia. While further studies are needed to clarify the magnitude of beneficial effects of l-theanine on specific mental health problems, taking a quality brand of this amino acid on a regular basis is a reasonable choice whether you are addressing a specific mental health problem or trying to improve your overall health and well-being.