L-Tyrosine is an amino acid found in the diet that is metabolized to produce catecholamines such as dopamine and adrenaline. It is also used in the production of thyroid hormones. For these reasons, weight loss supplements often include it.
When it comes to the topic of actually increasing dopamine and adrenaline outright, L-tyrosine does not seem to hold much promise. The synthesis of catecholamines is highly regulated in the body, so simply increasing the amount of L-tyrosine in your body does not necessarily increase catecholamine production.
However, some studies have noted that in stressful situations where noradrenaline exerts a protective effect, supplying L-tyrosine seems to provide a 'safety buffer' of building blocks that can prolong the anti-stress effect of catecholamines by delaying their depletion. This has been noted in situations of cold stress and sleep deprivation in humans but at a relatively high dose of 150mg/kg. Improvements in memory during stressful situations have also been found. However, more research is needed to confirm this. What little research we have doesn't suggest an effect on depression.