People who experience excessive periods of euphoria and uncontrollable hyperactivity countered with periods of feelings of worthlessness and guilt and frequent thoughts of suicide may be suffering from:

The correct answer is bipolar disorder.

Bipolar disorder (BPD) or manic depression refers to psychological disorder characterized by experiencing intense and extreme emotional states (known as episodes) that fluctuate in cycles. Individuals with BPD might experience feelings of extreme happiness, confidence, energy and creativity (mania) for a few days or weeks followed by an episode of deep depression, worthlessness and suicidal thoughts that lasts for a few days or weeks.