?Abstract When a choice is given between two different rewards, we tend to compare them to each other in order to choose the one that would fit the best. We usually have the choice between an immediate smaller rewards or a larger but delayed reward. After comparing the pro and cons, we, most of the time, end up preferring to wait and receive a better reward later than a smaller one right now. However, this is not an easy task for individuals who suffer from psychological disorders, such as Attention Deficit/Hyperactivity Disorder (ADHD), experience mood disorder, or have memory deficit. In this paper, we will see how different experiments based on diverse individuals showed some differences and similarities when coming to choose between a small, immediate or a larger but delayed reward. Thus, we assess why some people would rather choose those kinds of reward rather than others, depending on their behaviour. We conclude that people with memory disorder, impulsivity disorder and other conditions would alter their choices in any decision-making. We will see throughout different trials how psychologists and researchers found different ways to understand why they chose slighter, instant rewards or future, larger rewards and in which cases. Some experiments were made on animals whereas other were made on individual with and without condition; therefore, some experiment results contradict each other while in others we can find some similarities in the outcomes. An Analysis of Delay Gratification Making the right decisions, opting for the finest are choices regulated by our ability to restrain and behave. Thus, when we opt for a future-larger reward rather than a smaller but immediate one, we call it delay gratification. Denying an immediate reward and being able to imagine greater future reward is accomplished by some part of our brain. In fact, some studies have found that if a specific part of the brain is damaged, our ability to make decision is strongly affected. Moreover, for some individual suffering from Bipolar Disorder (BD), Schizophrenia (SZ) or ADHD, it can strongly alter in their way of making decisions. Knowing that, research have been made in order to find out why some individual tend to precipitate and choose immediate rewards, as well as methods to cope this tendency of impulsivity. We will focus as well on how researchers focused on patients with disorder and compare their decision making with healthy individual. The article Delaying Gratification, When the Reward is Under Our Noses (2013) is presenting the subject of delayed gratification associated to some of our brain structure. A recent study has shown that the hippocampus (HPC) might have an impact on imagining upcoming situations and therefore delay the recompense for a better one. The more the hippocampus is functioning, the better the capacity to perceive in the future. In order to support their theory, researchers at the Brain and Spine Institute in Paris made an experiment; however, the number of participants was not specified. They chose people who were completely healthy, and some suffering with disorders such as the Alzheimer’s disease. Both groups had to choose between taking a reward today or imagine a better-delayed reward. The people with no disorders chose to wait longer but have the better reward, while the people with the Alzheimer’s disease were incapable of creating a picture in their mind, because of their hippocampus damage due to their syndrome. In fact, people who have hippocampus impairment suffer from memory deficit but also a difficulty to imaging goals. Therefore, patients would tend to choose immediate rewards. The previous study has found that part of our brain’s memory system, specifically the HPC, is linked to our ability to select future rewards rather than immediate. Hence, individual with no particular brain damage would not have any problem imagining future rewards and therefore would chose the delayed one. In contrast, patients with brain damage would suffer from impulsive rea