EFFECT OF METHEDRINE ON CRITICAL FLICKER FUSION AND ITS RELATION TO PERSONALITY AND AFFECT

Abstract

This study was carried out to devise a method for measuing tolerance to a central excitant drug, methedrine, and to explore the psychiatric relevance of this measure. The test consisted of determining the effect of 0.15 mgm/kg of intra-venous methedrine on critical flicker fusion threshold (CFF). In initial studies, methedrine was shown to increase CFF, in contrast to water injection or no injection; the increase occurred in about 75% of subjects. The repeatability of CFF over the 30-minute test period was also shown to be adequate, although the day-to-day repeatability was low. The methedrine-CFF test results of 75 psychiatric patients were than compared with: psychiatric diagnosis, preinjection affect, affective change following methedrine, clinical appraisal of hysterical-obsessional trend, Guilford R and S scores of introversion-extraversion, I.P.A.T. anxiety score, and sedation threshold. The effects of age, sex, smoking, previous drugs, and time of day on the methedrine-CFF results were also assessed. The following statistically significant relationships were found between variables studied. (a) Patients who smoked before the test showed less increase of CFF after methedrine. (b) The incidence of increased dysphoria after methedrine was less in previously elated and non-dysphoric than in dysphoric patients. There was no difference between patients with anxiety and depression in affective reaction to methedrine. (c) Patients with neurotic depressions? or anxiety states showed more frequent decreases and less mean increase in CFF than patients with psychotic depressions, mixed neuroses, or hysteria. (d) There was a questionable trend for patients with high Guilford introversion scores to show greater CFF increases after metherdrine. It was considered that the. relationships between psychiatric diagnosis and the CFF change with methedrine, which parallel sedation threshold findings, encouraged further work along the lines of the present study, although a less difficult indicator than CFF would be desirable.