A multiple-dose, controlled study of phenelzine in depression-anxiety states

In a double-blind, controlled experiment, 62 outpatients with symptoms of depression with anxiety were selected for treatment with phenelzine sulfate, 60 mg daily, phenelzine sulfate, 30 mg daily, or placebo for six weeks. Forty-nine patients (79%) completed the experiment. Phenelzine sulfate, 60 mg daily, was significantly more effective than placebo in relieving symptoms of both depression and anxiety. Phenelzine sulfate, 30 mg daily, did not differ from the placebo. Only phenelzine sulfate, 60 mg daily, resulted in a median inhibition of platelet monoamine oxidase that exceded 80%. The results confirm a previous study that found phenelzine to be effective in the treatment of outpatients with depressive-anxiety states. Drug dosage is an important variable influencing clinical outcome in this patient group.

Catechol O-methyltransferase in red blood cells of schizophrenic, depressed, and normal human subjects

Catechol O-methyltransferase of lysed human red blood cells was assayed under optimal conditions, using saturating concentrations of the substrates, S-adenosyl-L-methionine and 3-4-dihydroxybenzoic acid. The mean enzyme activity found in 24 normal subjects was 29-2 nmol/hr/ml RBC. The mean activity in blood of 33 female unipolar depressives was not significantly different from normal. However, higher enzyme activities were observed in the blood of 11 schizophrenic patients (38-9 nmol/hr/ml RBC). Partially purified enzyme preparations from blood of normal and schizophrenic individuals were indistinguishable with respect to substrate specificities, isoelectric pH values, and ratios of the two O-methylated products. Therefore it is unlikely that any defect in O-methylation which may occur in schizophrenia can be attributed to a change in the intrinsic properties of erythrocyte catechol O-methyltransferase.

Serum creatine phosphokinase in acute psychosis

Fifty-four patients suffering from a variety of psychotic states were graded by their degree of psychomotor activity. Serum creatine phosphokinase (cpk) levels were found to be related to the degree of psychomotor activity, irrespective of the diagnostic category. Retarded and withdrawn patients had normal serum CPK, but on their return to normal psychomotor activity the CPK levels tended to rise transiently. It appears that unphysiological motor activity has a more direct relationship to the rise of serum CPK than motor activity per se.

A sensitive non-isotopic assay for monoamine oxidase activity in human blood platelets

A sensitive and specific procedure for measuring monoamine oxidase (MAO) activity in human platelets is described. Serotonin is used as substrate and formed 5-hydroxyindoleacetic acid (5-HIAA) is separated by a double microcolumn technique on Sephadex G-10 and Amberlite CG-50 and measured fluorimetrically. MAO activities were 5.11 +/- 1.32 (mean +/- S.D.) nmol/mg protein/hour in male and 7.85 +/- 1.58 in female healthy adults (p less than 0.001). MAO activity measured in 32 depressed patients was in a range of 3.20-10.62 nmol/mg protein/hour, the value not differing from that in the normal subjects. No significant difference was established between three subtypes of depression, in bipolar, unipolar and involutional patients, while significantly higher values were evident in female than in male patients (p less than 0.001).

Is there an increase in monoamine-oxidase activity in depressive illness?

In a group of depressed patients who had either been treated with or considered suitable for monoamine oxidase (M.A.O.) inhibitor therapy, a highly significant decrease in conjugated tyramine output was observed after an oral tyramine load compared with normal controls. However, there was no difference in conjugated isoprenaline output between the two groups after isoprenaline ingestion, even though this amine is almost solely metabolised by what is likely to be the same conjugation mechanism. Whilst some explanation in terms of altered gut motility is conceivable, it seems more likely that the apparent deficit in tyramine conjugation in depression represents an increase in functional M.A.O. activity. Consequently, this enzyme would metabolise a greater proportion of available amine, causing a proportionately large decrease in the smaller conjugate pool.

Correlation between blood gases, glycolytic enzymes and EEG during electroconvulsive treatment in relaxation

Twenty-three psychiatric patients were investigated during electroconvulsive treatment in relaxation. The blood gases, pH and serum bicarbonate levels in blood samples from the internal jugular vein and the femoral artery were measured radiometrically. The LDH fractions were separated electrophoretically and their activity, along with the activity of aldolase, was then determined on test materials. EEG recordings were made during the seizure and also during postconvulsive restitution. The following conclusions were drawn: (1) There was no evidence of anoxic anoxia in the brain during and after seizures. (2) A close relationship was found between the corresponding phases of electrical activity and brain metabolism as indicated by the blood gas changes during postconvulsive restitution. (3) On the basis of the increased glycolytic activity in the sera it is probable that glucose metabolism was shifted in the anaerobic direction during postconvulsive restitution of the brain tissues.

Creatine phosphokinase activity in newly admitted psychiatric patients

Increased serum creatine phosphokinase (C.P.K.) levels have been shown in acutely psychotic patients on admission to hospital (Meltzer, 1968). Little is known about C.P.K. activity in non-psychotic (e.g. neurotic) patients admitted under similar conditions. Psychotic patients have not been compared with non-psychotic patients over a period of time following admission. Examination of a single serum sample for C.P.K. activity in non-psychotic patients at the time of admission has shown no abnormality (Meltzer et al., 1969).

Reduced catechol-O-methyltransferase activity in red blood cells of women with primary affective disorder

Red blood cell catechol-O-methyltransferase, histamine-N-methyltransferase, and a methanol-forming enzyme were examined in a number of subjects with mental diseases. Catechol-O-methyltransferase activity was significantly reduced in female subjects with primary affective disorder (depression) as compared to normal women and men, men with primary affective disorder, and schizophrenic men and women. In depressed women, histamine-N-methyltransferase activity was elevated and the methanol-forming enzyme was unchanged.

Tryptophan pyrrolase--a biochemical factor in depressive illness?

Reserpine, which depletes brain amines, not infrequently causes depression (Bunney and Davis, 1965), whereas monoamine oxidase inhibitors (MAOI) which raise brain amine levels (Macleanet al.,1965) may alleviate depressive symptoms. The alleviation has been reported to be enhanced by tryptophan (Coppenet al.,1967), which is a precursor of the amines 5-hydroxytryptamine (5HT) and tryptamine. The apparent prophylaxis by tryptophan of an annual episode of depression has also been reported (Hertz and Sulman, 1968). These findings suggest that elevation of one or both of the above amines is responsible for the therapeutic effect of MAOI, and that their insufficiency may be responsible for symptoms of the disease. Defective 5HT synthesis in depressive illness is indicated by a number of findings. (1) Depressed patients responding to the MAOI drug iproniazid were found in two studies (Pare and Sandier, 1959; Praag and Leijnse, 1963), though not in a third (Burgermeisteret al.,1963), to have a lower initial urinary excretion of the 5HT metabolite 5-hydroxyindole acetic acid (5HIAA) than those who did not respond. (2) Depressed patients have a low content of 5HIAA in the lumbar cerebrospinal fluid (Ashcroftet al.,1966), which rises on recovery. Although work using animals (Guldberg and Yates, 1968; Ecclestonet al.,1968) shows that changes in brain 5HT are paralleled by changes of 5HIAA in the CSF, the significance of this result is not altogether clear, as lumbar 5HIAA depends not only on brain 5HT metabolism but also on 5HIAA transport within the CSF (Ashcroftet al.,1966). Furthermore, a small group of acute schizophrenics on phenothiazines also had low 5HIAA. (3) There is some direct evidence of low 5HT (Shawet al.,1967) or 5HIAA (Bourneet al.,1968) in the hindbrains of depressive suicides. (4) While single doses of 5-hydroxytryptophan, the immediate precursor of 5HT, do not alleviate depression, the remission of a prolonged episode of severe depression by administration of 5-hydroxytryptophan for five days has been reported (Persson and Roos, 1967).

5-Hydroxytryptamine in the hind-brain of depressive suicides

There is growing evidence of a connection between the metabolism of monoamines and severe depressive illness, but the exact role of these substances in affective disorders has yet to be defined. We know that reserpine depletes the brain of monoamines and that a proportion of patients treated with this compound develop a depressive illness. Conversely a number of compounds which raise the levels of amines in the brain by blocking the enzyme monoamine oxidase have been used in antidepressant therapy. The knowledge that loss of amines may be associated with depression, and that their replenishment in the brain may induce recovery, immediately leads to the question as to which of the biogenic amines is responsible for the affective changes. Pollin, Cardon and Kety (1961) observed the effect of giving various amino acids together with a monoamine oxidase inhibitor (M.A.O.I.) to patients suffering from chronic schizophrenia. They found that only tryptophan, the precursor of the monoamine 5-hydroxytryptamine (5HT), produced an elevation of mood. On the basis of their results, Coppen, Shaw and Farrell (1963) treated a number of patients suffering from severe depressive illness with M.A.O.I. and half of this group also received an oral dose of a suspension of D L-tryptophan (214 mg./kg. body weight) for one week. The patients taking tryptophan and M.A.O.I. recovered more rapidly than those receiving M.A.O.I. alone both while they were on tryptophan and also subsequently. One explanation for these findings was that the combination of M.A.O.I. and tryptophan increased the amount of amines derived from tryptophan in the brain, and that it was this which was responsible for the therapeutic effect. If this were so, then there were several possibilities. The first was that the level of 5HT in the brain was low in depression and the combination of amine precursor and enzyme inhibitor brought it back to normal. Alternatively it may be that recovery occurred as a result of the presence of abnormally large quantities of 5HT in the central nervous system or even following the production of tryptamine, another amine derived from tryptophan.