ABSTRACT
The aim of this pilot study was to evaluate a potential skin test for schizophrenia based on the effect of aqueous methyl nicotinate (AMN) on the production of prostaglandin D2 (PGD2) from skin macrophages and the resultant cutaneous capillary vasodilatation. Four concentrations of AMN were applied topically to the forearm skin in patients and controls, and any resulting vasodilatation was rated as redness after 5 min. The test was carried out on 38 patients with schizophrenia diagnosed according to DSM-III-R criteria, and 22 normal control subjects. At all concentrations of AMN, the schizophrenics were highly significantly different from the controls. One concentration gave the greatest degree of differentiation: at this concentration at 5 min, 83% of schizophrenics but only 23% of controls had a zero or minimal response to AMN. The skin flushing seen after oral administration of nicotinic acid is due to the same reaction, and this has been normal in those with affective illness and neurosis; cyclo-oxygenase inhibitors, e.g., aspirin, give a false-positive result (failure of vasodilatation). This result is consistent with the concept of reduced membrane arachidonic acid levels in schizophrenia. This test may contribute to the reliable diagnosis of schizophrenia.
Subject(s)
Flushing/chemically induced , Nicotinic Acids , Schizophrenia/diagnosis , Adult , Arachidonic Acid/blood , Docosahexaenoic Acids/blood , Dose-Response Relationship, Drug , Erythrocyte Membrane/metabolism , Feasibility Studies , Female , Flushing/physiopathology , Humans , Male , Middle Aged , Pilot Projects , Prostaglandin D2/metabolism , Psychiatric Status Rating Scales , Reference Values , Schizophrenia/physiopathology , Sensitivity and Specificity , Skin/blood supply , Vasodilation/drug effects , Vasodilation/physiologyABSTRACT
There are several reports of abnormalities in fatty acids in brain and blood phospholipids in schizophrenic patients. In order to see if the broad categories of negative and positive schizophrenia were linked to specific changes in fatty acids, an initial study was made of patients showing severe symptoms of these two types. Thirteen patients had persistent chronic negative symptoms of apathy and withdrawal while 12 patients had persistent positive symptoms of either thought disorder or hallucinations and delusions. The positive and negative groups were matched for length of history and drug exposure. Negative symptoms were associated with high levels of saturated fatty acids and low levels of long-chain unsaturates in red blood cell (RBC) membranes, while the positive symptom patients showed the opposite picture. In order to see if this bimodal distribution would be found in patients diagnosed as schizophrenic but without classification of symptoms, we examined frequency distribution curves for fatty acids in plasma and in RBC membranes in 68 individuals classified as schizophrenics and 259 normal individuals. A bimodal distribution was found for 20- and 22-carbon unsaturated fatty acids in RBC membranes from the schizophrenics; the same fatty acids in normal RBC membranes showed an unimodal distribution.
Subject(s)
Erythrocyte Membrane/physiology , Schizophrenia/blood , Schizophrenic Psychology , Adult , Biomarkers , Fatty Acids/physiology , Female , Humans , Male , Membrane Lipids/physiology , Middle Aged , Phospholipids/physiology , Psychiatric Status Rating Scales , Schizophrenia/classification , Schizophrenia/diagnosisABSTRACT
Forty-eight male detoxified alcoholics completed the automated neuropsychological tests, Cogfun II and the Perceptual Maze Test. On both tests, the younger group of patients performed better than the older group. No differences were found between short- and long-term drinkers, although there was some indication that older long-term drinkers performed less well than younger long-term drinkers. Control subjects performed significantly better than alcoholic subjects. Thus characteristics found by others using conventional psychometric tests were also apparent when using new, automated tests, and baselines were established from which to measure change over the passage of time.
Subject(s)
Alcoholism/diagnosis , Neuropsychological Tests/methods , Adult , Age Factors , Brain Damage, Chronic/diagnosis , Diagnosis, Computer-Assisted , Humans , Male , Middle Aged , Time FactorsABSTRACT
A double-blind trial carried out with alcohol-dependent males randomly allocated to n-6 essential fatty acid (EFA) supplementation or placebo capsules over a 6-month period incorporated a battery of automated neuropsychological tests. Results from problem-solving and perceptual motor speed tests are used. The effect that EFA supplementation had on recovery over 6 months of abstinence is shown, as well as the tests in which younger (aged 20-39) alcohol-dependent males differ from the older (aged 40-59) subjects.