Straight ristrettos—shots that are traditionally drunk from a demitasse and not diluted into a larger cup containing milk or water—could be described as bolder, fuller, with more body, and less bitterness, but with a higher concentration of acidity. These characteristics are usually attributed to espresso in general but are more pronounced in a ristretto. Diluted into a cup of water (to make an Americano or long black) or milk (e.g. latte and cappuccino), ristrettos are less bitter and exhibit a more intense espresso character.
Drinking more coffee is linked to a lower risk of depression, according to a review of 26 studies published in Australian & New Zealand Journal of Psychiatry in 2016. For each cup of coffee consumed per day, the risk of depression decreased by 8 percent, the researchers found. However, it's worth noting that too much caffeine can cause problems in people who also suffer from anxiety, negating any beneficial effects the coffee can have on depression risk.