Mood disorders, including depression and bipolar disorder, are among the most common and debilitating mental health conditions. These disorders not only impair the quality of life of suffering individuals, but also are major risk of suicide, which is a leading cause of death worldwide. Traditional methods of diagnosing and treating mood disorders though appear to be effective; they often face limitations in terms of accessibility, cost and personalization. On other hand suicide prevention remains a very delicate issue. Artificial Intelligence (AI) has emerged as a promising tool to address these challenges, offering innovative solutions for early detection, treatment, and ongoing management of mood disorders and suicide risk. This chapter explores the role of AI in addressing mood disorders and suicide prevention, highlighting various applications, benefits, limitations, and future directions in this field.