These comprise of groups of disorders occurring in an individual in alternating ways within a period of time, usually more than a week.

Those disorders include mania, hypomania and depressive face. Symptoms are are essentially everyday behavioural patterns that occur everyday for too long a time or with too high or low energy. Normal daily activities may involve a spike in energy, sudden low or increased appetite,, poor sleep or reduced need for sleep, increased libido, reduced libido, dangerous adventure tendencies and so on and so forth. When it becomes a severe illness, there could be psychotic symptoms in which case, the behaviour is noticeably completely out of touch with reality.

Etiological factors are similar to those of Schizophrenia.