Identifying Bipolar Disorder Symptoms

Thomas is a 22-year-old college student who has recently observed a marked change in his behavior. He frequently experiences intense feelings of euphoria and demonstrates episodes of impulsive decision-making, such as spending large sums of money he cannot afford on extravagant purchases. These episodes of highs are interspersed with periods of extreme irritability, poor concentration, and feelings of hopelessness. Despite his fluctuating moods, he seldom seeks help, fearing he may be perceived as weak or unstable. Friends and family have noted that these changes create significant disruptions in his social and academic life.

Based on this description, which psychological disorder is most likely affecting Thomas?