Donald J. Dillon

Noradrenergic function in panic disorder effects of intravenous clonidine pretreatment on lactate induced panic

To assess the role of noradrenergic stimulation during lactate-induced panic, ten patients with panic disorder who panicked during a standard sodium-lactate infusion underwent a repeat infusion following intravenous clonidine pretreatment. Although clonidine significantly lowered prelactate systolic blood pressure, the drug did not significantly lower prelactate anxiety levels, as reflected by the Acute Panic Inventory (API). Clonidine blocked lactate-induced panic in four of ten subjects, a significant effect. Clonidine treatment also significantly attenuated lactate-panic symptoms, as reflected by time to panic and API comparison between trials. Nevertheless, over half the subjects still panicked in response to lactate despite clonidine. This preliminary study suggests that reduction of central noradrenergic activity by clonidine, at least at the dosage levels employed in the current study, only partially attenuates panic response to lactate. Noradrenergic theories of panic may not therefore fully account for lactate panicogenesis.

SDT analysis of binary decisions and sensory intensity ratings to noxious thermal stimuli

During three sessions, each of 24 Ss responded to noxious thermal stimuli, using the following judgments: binary decision, S responded “high” or “low”; sensory intensity rating, S rated his sensory experience along a thermal intensity continuum; and concurrent report, S’s binary decision was followed by an intensity rating. The binary-decision d’ was significantly higher than the rating d′, suggesting that Ss could not maintain multiple thermal criteria in a consistent fashion. The criteria for pain obtained with single and concurrent intensity rating judgments did not differ. These results suggest that the most efficacious and valid method for the study of experimental pain is to obtain concurrent responses, and to use binary decisions to compute d’ and sensory intensity ratings to locate S’s criterion for reporting pain.

The Variation of Flicker-Fusion Thresholds Among Groups of Hospitalized Psychiatric Patients

(1961). The Variation of Flicker-Fusion Thresholds Among Groups of Hospitalized Psychiatric Patients. The Journal of Psychology: Vol. 51, No. 2, pp. 351-360.

Antipanic drug effects during lactate infusion in lactate-refractory panic patients

In previous articles we have reported on the total Acute Panic Inventory (API) score during lactate-induced panic. Even patients with panic disorder who do not panic during lactate infusion have higher API scores during the infusion than normal controls. In this post hoc analysis, we wished to determine whether specific API items were more sensitive to the beneficial effects of antipanic medication, either at baseline or during the infusion, in these lactate-insensitive panic patients. Four of the 17 items showed specific drug blockade of baseline severity. Five additional items showed specific drug blockade of lactate exacerbation of symptom severity. Medication apparently had no effect on severity of the remaining eight items. We suggest that the nine symptoms that responded to drug therapy are associated with hyperventilation. The study indicates that antipanic drugs may have a specific effect in blunting hyperventilation.

Wavelength, Area, and Intensity as Determinants of the Flicker-Fusion Threshold

CFF thresholds were obtained from 3 observers at each of 5 frequencies, 5 areas and 4 wavelengths of the stimulus, and the slopes of the log I-log A curves computed. The significance of the wavelength effect and of the interaction effect of frequency and wavelength upon these slopes indicates that wavelength is a determinant of the CFF threshold. The slopes for the red and blue stimuli were greater than those for the yellow and green at the higher frequencies.

Temporal summation of pain from radiant stimulation

Latency thresholds of pricking pain, using radiant thermal stimulation, were obtained. Ten Ss were tested for 10 sessions, and, in each session, single latency determinations were made at each of 10 stimulus intensities. Each intensity was administered to a different spot along the volar surface of S’s nonpreferred forearm. Thus, 10 latency thresholds were obtained from each S at. each intensity and each spot. Initial skin temperature was controlled so that a threshold determination was made when skin temperature measured 33.5° ± 0.5° C. Analysis of variance of the log10 t (seconds) values revealed a highly significant linearity of regression of log t on log intensity, thus confirming the hypothesized inverse and exponential relationship between latency and intensity. The parameters (slope and x-intercept) of the curve were discussed. The x-intercept may be interpreted as an index of an aversive threshold and could be used as a possible measure of the physiological component of pain.

LENGTH JUDGMENT IN PSYCHOTIC AND CONTROL POPULATIONS

For years, psychologists and psychiatrists have been interested in finding objective indicators of psychopathologic conditions. W i t h the rise of psychopharmacology in recent years, this interest has intensified and gained in dimension, i.e., since drugs alter behavior, many investigators have developed tests sensitive to these changes, and, it was hoped, such tests might properly be used psychopathologically. One has only to think of the investigations of such workers as Eysenck ( 3 ) and Lehrnann ( 5 ) . In recent years, the author has been involved with the investigation of the effects of various types of psychiatric therapy upon certain psychophysiological measures ( 1, 2 ) .3 Treatment with various phenothiazine derivatives was included in this therapeutic list. An opportunity to add several tests to the battery presented itself while the phenothiazines were being tested. T w o tests were added, the first of which was the judgment of length as described by Fleishman ( 4 ) . This test of length judgment was designed to determine the possibility of employing a test of this type in order to indicate changes induced by eleccroconvulsive therapy ( E C T ) or by phenothiazine treaunent or to point up differences between a population of normal controls and a population of hospitalized psychiatric (schizophrenic) patients.

Voice fundamental frequency changes associated with clinically identified stress state

An upward shift in voice fundamental frequency (pitch) has been reported in human subjects undergoing a wide variety of experiences that are assumed to be stressful [J. K. Darby, Ed., Speech Evaluation in Psychiatry (1981)]. Precise measurement of pitch rise as a function of ongoing physiological stress level was obtained from 35 patients with panic disorders and 18 controls undergoing a biochemical challenge (infusion of sodium lactate) that is known reliably to elicit stress reactions from panic patients within 20 min, but not from normals. Pitch was computed from the narrow‐band harmonic spectrum of the word “five” uttered during the course of a counting task performed at 5‐min intervals during the infusion. Twenty‐one patients who panicked showed an average pitch rise of about 1 semitone in the 5‐min period before panic, and reached a maximum of 2 semitones which was significantly related to time of panic onset. Among 14 patients who did not panic, pitch showed no consistently upward trend, but did re...

The reliability of an extrapolated measure of an aversive threshold of pain from radiant stimulation

The relationship between the logarithm of pain threshold latency (sec) and the logarithm of the stimulus intensity (mcal/cm2/sec) has been shown to be linear, and the extrapolated x-intercept value of the linear equation could be a useful measure in pain research. In order to assess the reliability of the x-intercept, pain latency thresholds, were obtained from 23 Ss by utilizing the D’Amour-Smith modification of the dolorimetric technique and by testing under a variety of conditions at each of four stimulus intensities. The empirically determined log t (sec) values were shown to be slightly, but significantly, higher when stimulation was applied to either the dominant limb or to the legs rather than to the nondominant limb or to the arms. The computed slope and x-intercept values did not differ between limbs or between dominant and nondominant sides. None of the three measures changed significantly between the two sessions. The x-intercept value was interpreted as an index of a threshold of aversion and its meaning and applicability were discussed.