Rumination is one of the important cognitive processes in explaining the persistence of depressive symptoms in young children and adolescents, which is characterized by a frequent, prolonged, and often unproductive focus on negative emotions, unpleasant experiences, perceived failures, and possible consequences of life events. Instead of helping to solve the problem and reduce psychological discomfort, this cognitive process can cause the persistence of negative thoughts, intensify unpleasant emotions, and reduce a person's ability to adapt to difficult situations. Young childhood and adolescence are considered as critical stages of psychological development, because in this period, cognitive skills, emotion regulation, self-awareness, social evaluation, and coping with environmental pressures are still being formed. Children and adolescents in this stage may have a limited ability to constructively process their emotions when faced with academic failure, family conflict, friendship problems, peer rejection, or failure experiences, and as a result, they return to unpleasant events and their personal meaning many times. Rumination in such a situation can transform from a temporary reaction to discomfort to a recurring pattern that facilitates the persistence of depressive symptoms. From a theoretical perspective, rumination has an important place in the framework of cognitive approaches to depression because these approaches emphasize the role of negative interpretations, dysfunctional beliefs, and information processing patterns in the formation and persistence of depressive states. According to this view, a child who sees academic failure as a sign of his or her own worthlessness or attributes disagreements with friends to his or her constant inability to communicate may think about his mistakes over and over again and reach negative conclusions about his personality and future instead of realistically examining the situation. In this situation, rumination helps to reinforce negative perceptions of oneself, the environment, and the future, and can increase feelings of hopelessness, sadness, and helplessness. One of the important characteristics of rumination is the repetition of thoughts without achieving a clear conclusion or practical solution. For example, a teenager who repeatedly asks himself why others don't like him, why he always fails, or why he can't be as successful as his peers may spend too much time mentally analyzing negative experiences without being able to weigh the evidence or take effective action to change the situation. Such a pattern can distract a person from positive opportunities, enjoyable activities, and successful experiences. As a result, a child or adolescent may gradually feel that life circumstances are unchanging and that it is useless to try to improve the situation. These perceptions can be accompanied by decreased motivation, social withdrawal, and decreased academic performance, and may lead to persistence of depressive symptoms. One of the main mechanisms of the association between rumination and depression is increased mental access to negative memories and interpretations. When a child or adolescent repeatedly focuses on unpleasant experiences, they are more likely to recall more similar memories and evaluate past events through a more negative lens. For example, a student who repeatedly thinks about their disability after receiving a low score may also recall previous failures and interpret a series of scattered experiences as evidence of personal inadequacy. This process can transform the feeling of failure from a limited event into an overall self-evaluation. In such a situation, rumination is not only a reaction to negative mood, but it can also help maintain and intensify it. This two-way relationship suggests that depressed people may be more likely to engage in rumination, and rumination, in turn, may be associated with the persistence of depressed moods. From a cognitive processing perspective, rumination can reduce mental flexibility and trap a person in a cycle of repetitive and negative interpretations. Cognitive flexibility refers to the ability to examine situations from different perspectives, change thought strategies, and adapt to new information. When a child or adolescent becomes attached to a negative interpretation of events, they may ignore alternative explanations and align any new events with their previous beliefs. For example, if a teenager believes that no one is interested in him, he may see a friend's accidental neglect as a definite sign of rejection, but he may downplay the supportive behaviors of others. Repeating such patterns can stabilize negative beliefs and make them difficult to modify. On the other hand, rumination may impair working memory and attention capacity, reducing the cognitive resources needed for learning, problem-solving, and decision-making. A child whose mind is constantly preoccupied with worrying about past mistakes may be less focused when doing homework or may not be able to pay attention to conversation well in social situations. The performance decline caused by this situation can lead to new failures and provide more material for rumination. In this way, a cycle is formed between negative thoughts, decreased performance, increased frustration, and exacerbation of depressed mood. The role of emotion regulation in this process is also particularly important. Emotion regulation includes the ability to identify, understand, accept, and manage emotional reactions appropriate to the situation. Children who have difficulty naming emotions, tolerating discomfort, or using effective coping strategies may be more likely to resort to mentally repetition of unpleasant experiences. In such a situation, rumination can be an attempt to figure out the cause of the discomfort, but when it becomes a lengthy, fruitless process, it reinforces rather than diminishes the negative emotion. For example, a teenager who is unable to properly identify his feelings of anger, sadness, or frustration after an argument with a family member may repeatedly review the scene of disagreement in his mind and conclude that no one understands him. This perception can lead to increased isolation, a decreased willingness to talk, and persistent discomfort. In contrast, teaching emotion regulation skills can help children and teens know their emotions more accurately and distinguish between experiencing an emotion and reacting to it. Rumination is also associated with negative attributional styles. Attributional style refers to the way in which a person interprets the cause of events. Children and Teens