666. may Buddha bring good fortune to you.
The correct answer is bipolar disorder.
Bipolar disorder (BPD) which is also known as manic depression refers to a mental and psychological disorder in which sufferers experience intense and extreme emotional states known as episodes that fluctuate in cycles.To elaborate, individuals with BPD might feel extreme happiness, confidence, energy and creativity (mania) for a few days or weeks followed by an episode of deep depression that lasts for a few days or weeks.