The origin of the psychiatric features of psychotic patients and whether the features are basically psychological or biological has always been an issue of controversy. Some scientists have tried to prove the absolute relevance of these symptoms to psychological etiologies whereas others have insisted on biological causation. However, others have tried to find a link between the two etiologies in the formation of psychiatric symptoms and signs.

In this article, a model is proposed for the coexistence and cocausative role of biology and psychology in the formation of symptoms of psychotic patients and as an explanation for the high rate of coexistence of obsessive thoughts in obsessive-compulsive disorder and schizophrenia and their highly reported relevance. These two disorders are put on two sides of a similar spectrum. Through the article, evidence supporting this model from psychological (especially Jungian and modified Freudian views) and neurobiological theories (neuroanatomical, neurotransmitter, and neural network) models) is discussed.