Subjective experience of schizotropic vulnerability in siblings of schizophrenics

Abnormal neuropsychological and cognitive functions in nonpsychotic relatives of schizophrenics are currently the subject of intense interest, mainly because of attention being focused again on the theoretical construct of schizotaxia. Contextually, in recent years the issues of subjective experiences have once again become central and respectable topics in psychopathological research. Among self-experiential disturbances, basic symptoms (BS), stemming from Jaspersian phenomenological psychopathology, are considered the first, protopathic, subjective reverberation of the neurobiological deficit of schizophrenia. Thus BS are expected to be detectable in nonpsychotic relatives of schizophrenia patients. The aim of the present study was to compare the degrees of such anomalous subjective experiences, assessed in siblings of schizophrenic patients, schizophrenia spectrum patients (schizotypals and schizophrenics) and nonclinical controls. Different profiles of BS were obtained in the samples. An increasing gradient of BS ranging from nonclinical to clinical samples, with unaffected siblings in the intermediate position, occurred for some of the BS clusters (i.e. 'thought, language, perception and motor disturbances' and 'impaired bodily sensations'). Other BS clusters (i.e. 'disorders of emotion and affect' and 'increased emotional reactivity') turned out to be typical of the clinical subgroups, whereas an enhanced tolerance to normal stress significantly distinguished the sibling specimen from the other ones. The heterogeneity of these patterns suggests that BS constellations may be underpinned by different psychopathological processes and that cognitive and bodily BS may be clinical target phenotypes for schizotropic liability screening.