Gregory Sathananthan

Amphetamine psychosis: Behavioral and biochemical aspects ☆

Publisher Summary This chapter discusses the behavioral and biochemical aspects of amphetamine psychosis. Amphetamine psychosis was characterized by a brisk emotional reaction, usually in the direction of anxiety amphetamine psychosis was rather strikingly similar to schizophrenia in its presentation; however, these two conditions could be differentiated by the presence of thought disorder that is prominent in schizophrenia and lacking in amphetamine psychosis The pharmacologic manipulation of dopaminergic mechanisms is almost certainly not without effect on other central nervous system systems and certain effects considered dopaminergic may indirectly be mediated by these other systems. Physostigmine can both block and abolish the stereotypy in rats induced by the administration of methylphenidate.

Behavioral effects of l-Dopa in schizophrenic patients

As part of an investigation of the possible role of dopaminergic mechanisms in some psychoses, the behavioral effects of administration of l-Dopa to schizophrenic patients was assessed. l-Dopa was administered in dosages of 3–6 g/day to 10 such patients who had been maintained off neuroleptic drugs for approximately a week. Behavioral worsening occurred in all 10 patients. Three showed non-specific stimulation while the remaining 7 showed a combination of both stimulation and worsening of pre-existent symptoms or the development of new symptomatology. The significance of these findings is discussed with regard to those of other investigators.

Reaction Time as a Diagnostic Measure in Senility

ABSTRACT: Both simple and disjunctive reaction times (RT) are known to slow with aging but there is a paucity of information on RT changes in senility. Since disjunctive RT involves cognition in addition to the sensory‐motor speed and attentional components of simple RT, it was hypothesized that disjunctive RT would be a reliable index of age‐related mental decline. To test this prediction, simple and disjunctive RT were measured in matched groups of 20 normal and 20 cognitively impaired elderly. Simple RT was slower in the senile patients than in the normal subjects, but this difference was accounted for by differences in disjunctive RT. The senile patients showed a much larger performance decrement with respect to disjunctive RT than did the normal subjects — a difference which was not accounted for by differences in simple RT. In a discriminant function analysis, disjunctive RT alone correctly identified the senile patients and the normal subjects with 86 percent accuracy. Thus, this measure proved to be a reliable index of age‐related mental decline. Preliminary data indicate that disjunctive RT slowing is correlated with non‐memory mental decline, and that poor performance is related to the need for care and supervision.

Dimethyltryptamine levels in blood of schizophrenic patients and control subjects

A gas chromatographic-mass spectrometric determination of blood N,N-dimethyltryptamine in normal controls and schizophrenic patients was carried out with a sensitivity limit of 0.05 ng/ml whole blood. Although the results appear to suggest that the mean DMT level was higher in the total patient group, those patients with acute psychosis, female patients and patients with suspiciousness scores on the BPRS of 4 or over, the differences were not statistically significant.

Cognitive effects of ACTH 4–10 in the elderly☆☆☆

The polypeptide ACTH 4-10 has been shown to facilitate learning in animals, and possibly to improve attention and memory in normal human subjects. The purpose of this study was to assess the effects of ACTH 4-10 in cognitively impaired elderly subjects. In a double blind, cross over design, 24 cognitively impaired geriatric outpatients (mean age=71.4, 12 with mild and 12 with severe impairment) received injections of 30 mg or 15 mg ACTH 4-10 or matched placebo on 3 successive days. A cognitive test battery of memory and nonmemory tests was administered each day both before and after treatment. The 30 mg dosage produced a slowing of simple visual RT, a nonsignificant improvement trend in verbal associative memory, and significant, severity dependent facilitation or impairment in day later visual memory. The results suggest that the ACTH 4-10 effects on cognitively impaired elderly are dependent on the dosage and on the baseline cognitive level of the subjects.

Senile dementia: treatment with deanol.

Recent research indicates a possible cholinergic involvement in memory processes and thus the possibility that acetylcholine deficiency may underlie memory impairment in senile dementia. Deanol (2‐dimethylaminoethanol), which is assumed to increase brain acetylcholine, was given openly for 4 weeks to 14 senile outpatients, to determine the safety of the drug and whether or not it reduces cognitive impairment. The dosage was gradually increased to 600 mg three times daily during the first two weeks, with no adverse effects. Ten patients improved globally and 4 were unchanged (p < .01). The total score on the Sandoz Clinical Assessment‐Geriatric (SCAG) was lowered by the third week (p < .01), primarily as a result of reduced depression, irritability and anxiety, and increased motivation‐initiative. However, neither the clinical ratings nor an extensive pre‐ versus post‐treatment series of cognitive tests revealed changes in memory or other cognitive functions. Since a similar separate study with a different compound produced no behavioral changes, it is unlikely that the improvement with deanol was due entirely to placebo effects. The results thus suggest that although deanol may not improve memory, it may produce positive behavioral changes in some senile patients.

Plasma renin response to lithium in psychiatric patients.

Three hospitalized psychiatric patients with different diagnoses were monitored for plasma renin activity before and after subacute treatment with lithium carbonate. Plasma renin activity rose sharply after the first day on lithium and mean plasma renin values were elevated throughout the first week of treatment, returning to baseline levels during the second week. These changes occurred in all three subiects.

The Comparative Psychotogenic Effects of L-Dopa and ET-495

The ability of amphetamine and methylphenidate to cause a schizophreniform psychosis in non-schizophrenic individuals is one of the bases for the hypothesized relationship between dopaminergic hyperactivity and some psychotic states (Connell, 1958; Griffith, Cavanaugh, and Oates, 1970; Angrist and Gershon, 1970; Spensley and Rockwell, 1972; Bell, 1973). The demonstration that these same drugs caused florid exacerbation of symptomatology when administered to schizophrenics (Janowsky, El-Yousef, Davis, and Sekerke, 1973; Janowsky and Davis, 1974) gave impetus to this concept. However, amphetamine and methylphenidate clearly affect both norepinephrine and dopamine (Lewander, 1974; Scheel-Kruger, 1971; Ferris, Tang, and Maxwell, 1972) thereby making it difficult to specifically implicate dopaminergic mechanisms in their psychotogenic effects with certainty.

Behavioural and biochemical effects of l-dopa in psychiatric patients

Publisher Summary This chapter elaborates the behavioral and biochemical effects of l -dopa in psychiatric patients. Administration of the dopamine precursor, l -dopa to Parkinsonian patients has frequently precipitated psychotic reactions of various types. Patients who consented to participate were maintained on matched placebo for 5–10 days before l -dopa was administered. The first patient showed hypersexuality and compulsive masturbation without other signs suggestive of hypomania such as euphoria or hyperactivity. The second showed no objective behavioral effects and tolerated dosages of 10 g l -dopa day. Two other patients showed a combination of nausea, diaphoresis, a sense of dysphoric stimulation and anxiety. One of these developed ideas of reference. The remaining patient, who had no history of psychosis or psychiatric signs suggestive of schizophrenia, developed a paranoid schizophreniform psychosis. The precipitation of a schizophreniform psychosis by administration of l -dopa in a patient documented to be non-schizophrenic prior to receiving the drug also supports the hypothesized relationship between psychosis and central dopaminergic activity.

AMPHETAMINE PSYCHOSIS: BEHAVIORAL AND BIOCHEMICAL ASPECTS*

Publisher Summary This chapter discusses the behavioral and biochemical aspects of amphetamine psychosis. Amphetamine psychosis was characterized by a brisk emotional reaction, usually in the direction of anxiety amphetamine psychosis was rather strikingly similar to schizophrenia in its presentation; however, these two conditions could be differentiated by the presence of thought disorder that is prominent in schizophrenia and lacking in amphetamine psychosis The pharmacologic manipulation of dopaminergic mechanisms is almost certainly not without effect on other central nervous system systems and certain effects considered dopaminergic may indirectly be mediated by these other systems. Physostigmine can both block and abolish the stereotypy in rats induced by the administration of methylphenidate.