Psychophysiological studies in schizophrenic patients selected on the basis of a “genetic marker”

Abstract

Psychophysiological studies in schizophrenics have generally resulted in contradictory and inconclusive reports. The purpose of the present study was to determine whether a better psychophysiological separation of schizophrenic and control subjects could be accomplished by selecting them on the basis of a biological marker: the high plexus visualization score (PVS). Finger blood flow, skin temperature and electrodermal recovery rates were studied in 64 male schizophrenics (33 high PVS and 31 low PVS) and 24 male controls (10 high PVS and 14 low PVS) matched for age. All control subjects and 30 of the schizophrenics (16 high PVS and 14 low PVS) had been drug-free for at least 1 month. They were studied in a sound attenuated, temperature controlled room under 12 experimental conditions. The results demonstrate that, as predicted, schizophrenics with high PVS have the lowest finger blood flow rates, the lowest skin temperatures and the slowest GSR recovery rates of all groups studied. The largest difference in all three variables was found between high PVS schizophrenics and high PVS controls. The blood flow rates and the skin temperature were higher and the electrodermal responses were fewer in patients taking medications than in those receiving placebos. A suggestion of a bimodal distribution into "responders" and "non-responders" was apparent only in patients receiving medications.

Electrodermal activity in the affective disorders and schizophrenia

“…It has become increasingly clear that the use of chronically ill patients, particularly after years of institutionalized drug treatment, though it may be logistically more convenient, introduces distorting variables that can never be entirely eliminated. For example, a recent study (Maricq & Weinrich, 1980) examined electrodermal responsiveness in medicated and drugfree schizophrenics and reported a bimodal responder/non-responder distribution in the former group only. In addition to some of the difficulties referred to above, the incidence of often irreversible neurological syndromes due to neuroleptic drugs (Gibson, 1978) must make the interpretation of electrodermal data unnecessarily speculative, particularly when cerebral dysfunction is being considered as a possible basis for schizophrenia.…”

Psychophysiologic markers of psychopathology: A review.

“…Evaluation. In a series of investigations, Maricq (1963Maricq ( , 1966Maricq ( , 1967Maricq & Weinrich, 1980) has reported that from 25 to 70% of various samples of schizophrenic patients have a visible subpapillary plexus. In general, chronic or poorprognosis patients and those with a family history of schizophrenia are most likely to show visible capillaries (Maricq, 1963(Maricq, , 1966Norris, 1966;Pokorny, Mefferd, & Stevens, 1970).…”

“…This could be due to a combination of factors such as the pre-existing structural characteristics of nailfold skin, increased sympathetic tone leading to vasomotor constriction, and the special sensitivity of the small nailfold vessels to circulatory biogenic amines that are known to have vasoconstrictive effects. In support of this line of thinking, Maricq has undertaken a number of psychophysiological studies that show that schizophrenics with a visible plexus, compared to patients without this trait and normal controls, have lower finger blood-flow levels (Maricq, 1975; Maricq & Weinrich, 1980), larger electrodermal response recovery times (Maricq & Edelberg, 1975; Maricq & Weinrich, 1980), and lower skin temperature (Maricq & Weinrich, 1980). Whatever the explanation for the existence of this characteristic and its association with schizophrenia, nailfold capillary visibility clearly has potential as a genetic marker and merits further investigation in this regard.…”

Comparison of MAO, D β H, and COMT activities in chronic schizophrenics selected on the basis of nailfold capillary pattern

“…Buchunun & Jones (1969)). In a comparative study of schizophrenic subjects and normal controls using the psychophysiological variables linger blood flow, skin temperature, and ecteodermal recovery rates, Maricq & Weinrich (1980) found that most of the differences between schizophrenics and normals could be accounted for by the high PVS schizophrenic subgroup.…”