Psychosis can be understood only when we take into account the existence of the unconscious mind.
Without a belief in the unconscious we cannot understand psychosis.
It is the unconscious that brings forth our dreams and it is outside the realms of time, space and rationality.
It is the storehouse of all of our past experiences; joys, fears, worries, sadness, secrets etc.
It is full of all the unpleasant aspects that we do not even want to admit to ourself.
It is also the storehouse of all the sublime and joyful experiences that one can experience in this lifetime.
It is the unconscious that connects us to a larger universal mind from which it can draw both positive and negative thoughts
The unconscious mind has a much larger capacity than the conscious mind but it is the conscious mind that keeps the unconscious in check.
It is very much like the horse and the horseman where the horse represents the unconscious mind and the horseman the conscious mind. Normally the horseman is in full control of the horse, but in a psychotic state, it is the horse that takes over the horseman and takes him to places he may not want to go.
The symptoms of psychosis can be understood in terms of two broad categories
1.Exaggeration of our own fears, denials, projections and suspicions. The first part of psychosis can be understood in terms of things that we have thought about in the past. These experiences get stored in the unconscious mind and come out when the barriers between the conscious and the unconscious are weakened. This part of the mind can be described as the personal unconscious i.e. our own past collection of experiences.
2.Things that are totally bizarre and alien to us. This can be understood in terms of experiences coming from the collective unconscious, the part of mind that can also be described as the universal mind.