And then we have bipolar type I disorder. Bipolar sometimes can cause manic depressions. So people switch from depression and the manic state. So during one year sometimes for several months people can be in a very depressed mood. And for the other several months he or she can be in a very manic and excited mood. So typically involve episode of major depression and mania. So for both men and women, the instance of this disease is 1%, it's pretty high. So typical age of onset of bipolar is the late teens or early 20's. Symptoms of manic episode of bipolar, so the manic stage or manic episode, is a irritable mood for at least one week. And plus three additional symptoms. And so, what is the symptoms? So, symptoms for maniac episode is inflated self-esteem and decreased need for sleep and unusual talkativeness and pressured speech. And flight of ideas, racing thoughts. So, distracted. Very easy to be distracted, increased activity in daily life. Excessive involvement in pleasurable activities with potential for painful consequence. So these are the symptom for the manic states. In the course of this bipolar type I is in a cycle, as we said, and if from people to people the duration of this cycle can vary a lot. [INAUDIBLE] And one sort of the people in the video goes through only one cycle in five years. And 1% of the people goes one cycle every three months. So. And also, there is a so called rapid cycle. It's four or more cycle per year, happen in the patient. And bipolar, there's some other type of bipolar disorder. There's bipolar type II. Bipolar type II refers to the alteration or the change between hypomanic states to the major depression states. And there's a cyclothymic disorder. So this disorder referred to an alteration between depression and hypomanic episode. And this hypomanic episode. You can think this is a less where manic state, is elevated expansive and irritable mood for at least four days. Symptoms very similar to manic state, except no marked impairment happened.