The deficit syndrome and eye tracking disorder may reflect a distinct subtype within the syndrome of schizophrenia.

Although many researchers suspect that schizophrenia is a heterogeneous syndrome, identification of valid subtypes has been surprisingly difficult. Both the deficit syndrome and eye tracking disorder have been proposed as meaningful subtypes within schizophrenia. Despite a significant amount of research in these two areas, most of it has been conducted in parallel. Recent evidence suggests that the two phenomena are associated directly with each other. A review of the literature reveals that they share a common pattern of validators, ranging widely from risk factors to neurocognitive measures, that distinguishes them from other subjects with schizophrenia. This common pattern of validators suggests that the two phenomena share an underlying pathophysiology. Furthermore, a modest amount of evidence suggests that the deficit syndrome and eye tracking disorder each reflect a distinct subtype of schizophrenia, not simply a more severe form. If valid, then the evidence would suggest that the deficit syndrome and eye tracking disorder reflect the same distinct subtype within the syndrome of schizophrenia. Although this theory is in the early stages of development, it may prove useful for dissecting the heterogeneity in schizophrenia.