1 - Conceptual and theoretical issues in schizotypal personality research

Summary

Many researchers argue that research into schizotypal personality is important not only in furthering our understanding of this personality disorder, but also in providing key insights into our understanding of schizophrenia. For example, several studies have indicated that schizotypal personality disorder (SPD) is a disturbance that may be genetically related to schizophrenia, insofar as it is prevalent among first-degree biological relatives of schizophrenics. It is also argued that SPD research is of key importance in overcoming methodological weaknesses of schizophrenia research. Psychotic symptoms may mask and blur the more subtle cognitive impairments underlying the schizophrenia spectrum, and they also create difficulty in ensuring that schizophrenics fully understand and comply with the experimental protocol. In addition, effects of neuroleptics and lengthy hospitalization create further confounds in interpreting research on schizophrenic subjects. Thus, research in SPD has become increasingly important as a means of studying biological and cognitive markers of the schizophrenia spectrum without the confound of severe clinical symptoms.

Research since the 1980s has provided grounds for this optimistic view. Schizotypals have been shown to display a number of the biological/neuropsychological markers for schizophrenia, such as eye-tracking impairment, abnormalities on evoked potentials, and attentional deficits. In schizophrenics, these deficits have been linked to damage at brain sites such as the frontal lobes, temporal lobes, and subcortical areas. Examination of these markers is one of the central paradigms in schizophrenia research, and extension of these methods to those afflicted with SPD represents a significant test of the biological and neuropsychological processes thought to underlie schizophrenia. Such research in SPD may also identify those intact cognitive abilities that serve as “protective factors,” protecting some schizotypals from developing schizophrenia.