Two year maintenance treatment of duodenal ulcer disease with ranitidine 150 mg: a prospective multicentre randomised study. GEMUD (Groupe d'Etude de la Maladie Ulcéreuse Duodénale)

Maintenance treatment of duodenal ulcer (DU) with ranitidine 150 mg/day was compared with placebo in a two year prospective multicentre randomised study. Three hundred and ninety nine patients were included (mean age: 44.7 years, M/F ratio = 2.47/1; 37.6% of smokers) in placebo (n = 202) and ranitidine (n = 197) groups. Efficacy was assessed by the length of time to the first ulcer pain attack (with or without endoscopic confirmation) or DU complication. One hundred and fourteen patients of 399 (28.6%) had incomplete follow up. Actuarial survival curves of patients without ulcer pain (26 and 53% at two years in placebo and ranitidine groups, respectively) were significantly different (p < 0.0001). Endoscopies were performed depending on physicians' decision (mainly where there was severe pain or complication). Patients without relapses from endoscopy were more frequent in the ranitidine group (83%) than in the placebo group (47%, p < 0.0001). A greater incidence of complications, mainly bleeding, was also seen in the placebo group (13 complications v two in the ranitidine group, p < 0.002). No factor predicting DU relapse was identified. No important side effect was encountered. Ranitidine 150 mg/day is effective and well tolerated in preventing ulcer pain attacks and DU complications for up to two years.     

Roxatidine versus ranitidine in the treatment of duodenal ulcers: a randomized double-blind controlled multicentre study in Singapore

Roxatidine acetate, a new H2 receptor antagonist, was compared with ranitidine in the treatment of duodenal ulcers in a double-blind multicentre study. Eighty-four patients with endoscopically proven duodenal ulcer were randomized to receive 150 mg roxatidine acetate or 300 mg ranitidine at bedtime. Repeat endoscopy was performed after 4 weeks (25-33 days) and if the ulcer had not healed, another endoscopy was performed after a further 4 weeks of treatment. Using per protocol analysis 73.6% of ulcers treated with roxatidine healed at 4 weeks compared to 72.2% of ulcers treated with ranitidine (P = NS). The healing rates at 8 weeks were 92% with roxatidine and 83.3% with ranitidine (P = NS). Using equivalence tests, the healing rate of roxatidine was found to be equivalent to that of ranitidine within a 20% region. Roxatidine users took significantly less antacids than ranitidine users (P < 0.05). There were no significant adverse effects due to roxatidine or ranitidine. Roxatidine is a safe effective drug in the treatment of duodenal ulcers with a healing rate comparable to that of ranitidine.     

Inter-rater reliability for function and strength measurements in the acute care hospital after elective hip and knee arthroplasty

AIM: To investigate the efficacy and safety of daily low-dose colloidal bismuth subcitrate in reducing duodenal ulcer relapse. DESIGN: Double-blind, double-dummy group comparative clinical trial with random allocation. Healing Phase: colloidal bismuth subcitrate 240 mg twice daily vs ranitidine 150 mg twice daily for up to 12 weeks. Maintenance Phase: nightly, colloidal bismuth subcitrate 120 mg vs ranitidine 150 mg vs placebo for up to 12 months (high-risk patients received active treatment only). Assessment: clinical, endoscopy, random blood bismuth levels (and rapid urease test for Helicobacter pylori in a subgroup). PATIENTS: 194 with active duodenal ulcer. OUTCOME: Cumulative healing at 12 weeks was 93% on colloidal bismuth subcitrate (of 92 patients) and 97% on ranitidine (of 102 patients). Relapse at 1 year was significantly less on active treatment as follows: placebo (50 patients) 60%; ranitidine (71 patients) 21%; colloidal bismuth subcitrate (64 patients) 33%. This was independent of the results of the rapid urease test which was positive in 78%, 88% and 76% of the patients respectively. Treatment was well tolerated. The highest median blood bismuth level (mcg/L) was 25 in the healing phase and fluctuated between 6 and 10 in the maintenance phase. CONCLUSIONS: Colloidal bismuth subcitrate, 120 mg nightly, is effective in reducing duodenal ulcer relapse and is well tolerated.     

Omeprazole and ranitidine in long-term treatment of duodenal ulcer: a double-blind comparison of length of time in remission

In most patients duodenal ulcer is a chronic relapsing disease. If no active maintenance treatment or eradication therapy is given after healing, around 70-100% of patients have a relapse during the first year. We conducted a double-blind multicenter study in 472 patients with duodenal ulcer. They were treated with omeprazole 20 mg every morning for four or eight weeks and when healed were randomly allocated to maintenance treatment with either omeprazole 20 mg every morning or ranitidine 150 mg at bedtime for up to six months. The patients were assessed by endoscopy at monthly intervals until healing occurred. Thereafter scheduled endoscopy was carried out after 1, 3, and 6 months of maintenance treatment or immediately in the event of a suspected relapse. Healing status (intention to treat approach) was 87% at four weeks and 93% at eight weeks. At six months the estimated remission rate was 90% for omeprazole and 82% for ranitidine (P = 0.03, 95% CI 1-15%). The incidence of adverse events was similar during the two maintenance treatments. Treatment with omeprazole 20 mg every morning maintained significantly more patients in remission than treatment with ranitidine 150 mg at bedtime.     

Prevention of duodenal ulcer recurrence with 15 mg lansoprazole: a double-blind placebo-controlled study. The Lansoprazole Study Group

Although eradication of Helicobacter pylori cures duodenal ulcer, some patients are not infected and others are treatment failures. This randomized, double-blind, placebo-controlled study assessed the value of treatment with low-dose lansoprazole in preventing duodenal ulcer recurrence. One hundred eighty-six patients with endoscopic documentation of healed duodenal ulcer received 15 mg/day lansoprazole or placebo for 12 months or until ulcer recurred. Endoscopy results, symptom assessment, and fasting serum gastrin levels were obtained at multiple time points. Densities of E, EC, and G cells were assessed by biopsy when the ulcer recurred or at the final visit. Time to ulcer recurrence was significantly longer (P < 0.001) in the lansoprazole group (median >12 months) compared to placebo (median <3 months), and patients taking lansoprazole were asymptomatic longer (P < 0.05). Maintenance therapy with lansoprazole 15 mg/day suppresses acid and controls recurrence of duodenal ulcer disease.     

Non-verbal communication: evaluation of a computer-assisted learning package

To assess the effect of 4 weeks' therapy with ranitidine 150 mg twice daily on the healing of symptomatic NSAID-associated gastric and duodenal ulcers, 149 arthritic patients were randomly allocated to one of three treatment groups: ranitidine with NSAID continued, ranitidine with NSAID discontinued, and placebo with NSAID discontinued. The healing frequency in patients with gastric ulceration was 67, 68 and 47%, and in those with duodenal ulceration 61, 81 and 42%, respectively. Only the difference between the duodenal ulcer healing rates for ranitidine with NSAID discontinued and placebo was statistically significant (P = 0.02). Healing rates were uninfluenced by gender, age, smoking habits, alcohol consumption, ulcer frequency or size, arthritic disease, or participating country.     

Omeprazole/amoxicillin versus triple therapy for Helicobacter pylori in duodenal ulcer disease: two-year follow-up of a prospective randomized study

The present study was designed to compare the efficacy and tolerability of triple therapy and dual therapy for Helicobacter pylori in duodenal ulcer patients and to evaluate the long-term clinical course of ulcer disease. Forty duodenal ulcer patients with proven H. pylori infection were enrolled into the study and randomly treated with either triple therapy consisting of bismuth subsalicylate, metronidazole and tetracycline plus ranitidine or with dual therapy comprising omeprazole and amoxicillin. Patients were investigated clinically and endoscopically including assessment of H. pylori infection by means or rapid urease test, culture, histology and urea breath testing 4 weeks after cessation of eradication therapy, in 1-year intervals and when dyspeptic symptoms recurred. One patient of each group was lost during follow-up. H. pylori infection was cured by triple therapy in 84.2% and by dual therapy in 78.9% (p = 1.00). During follow-up, all patients with cure of H. pylori infection (n = 31) remained in stable remission with respect to duodenal ulcer disease, while 6 out of 7 patients persistently infected with H. pylori developed an ulcer relapse (p < 0.001). One patient with cured infection had had an episode of dyspeptic symptoms requiring pharmacotherapy and in another 3 patients mild refluxesophagitis without necessity of medical treatment had been detected on the occasion of a scheduled endoscopy. In the short-term, cure of the infection resulted in a marked reduction of the degree of antral gastritis and in a loss of activity in all but one patient.(ABSTRACT TRUNCATED AT 250 WORDS)     

One-week antibiotics versus maintenance acid suppression therapy for Helicobacter pylori-associated peptic ulcer bleeding

Bleeding peptic ulcer is the most important cause of upper gastrointestinal bleeding. Our aim was to compare the effect of anti-Helicobacter therapy with maintenance treatment of H2-receptor antagonist in the prevention of relapses of ulcer and bleeding. Patients with bleeding duodenal or gastric ulcers and H. pylori infection were randomized to receive either a one-week course of triple therapy with bismuth subcitrate, metronidazole, and tetracycline plus ranitidine or a six-week course of ranitidine 300 mg/day. After the ulcers healed, the antibiotic-treated patients were not given any medication, whereas the ranitidine-treated patients continued to receive a maintenance dose of 150 mg/day. One hundred twenty-six patients were randomized to receive anti-Helicobacter therapy and 124 patients to receive long-term ranitidine. H. pylori eradication was achieved in 98.2% in those who received triple therapy and 6.1% in those who received ranitidine (P < 0.0001). At the six-week follow-up, ulcer healing was documented in 88.2% in those who received triple therapy and 86.1% in those who received ranitidine (P = 0.639). Recurrent ulcer developed in nine of the ranitidine-treated patients and three of them presented with recurrent upper gastrointestinal bleeding. One patient in the antibiotic group developed recurrent ulcer without rebleeding (P = 0.01). It is concluded that eradication of H. pylori is sufficient for the prevention of recurrent bleeding ulcers.     

Treatment of Helicobacter pylori reduces the rate of rebleeding in peptic ulcer disease

BACKGROUND: We evaluated whether therapy designed to eradicate Helicobacter pylori infection resulted in a reduction in rebleeding in patients with peptic ulcer disease. Patients presenting because of major upper gastrointestinal hemorrhage from peptic ulcer and whose ulcers healed in a study in which they were randomized to receive ranitidine alone or triple therapy plus ranitidine were followed up regularly with endoscopy. No maintenance anti-ulcer therapy was given after ulcer healing. METHODS: Patients received ranitidine, 300 mg, or ranitidine plus triple therapy. Triple therapy consisted of tetracycline, 2 g; metronidazole, 750 mg; and bismuth subsalicylate, 5 or 8 tablets (151 mg bismuth per tablet), and was administered for the first 2 weeks of treatment; ranitidine therapy was continued until the ulcer had healed or 16 weeks had elapsed. After ulcer healing, no maintenance antiulcer therapy was given. Development of ulcer recurrence with or without recurrent upper gastrointestinal bleeding was evaluated. RESULTS: Thirty-one patients with major upper gastrointestinal bleeding from peptic ulcer were studied; 17 received triple therapy and 14 ranitidine alone. Major rebleeding occurred significantly (p = 0.031) more often in those in the ranitidine group (28.6%), compared with none (0%) in the triple therapy group. CONCLUSION: Eradication of H. pylori infection reduces the rate of ulcer recurrence and rebleeding in complicated ulcer disease.     

Early evening dosing of ranitidine. Comparison with nighttime dosing of ranitidine or cimetidine in duodenal ulceration

A double-blind multinational comparison of ranitidine 300 mg post evening meal (pem), ranitidine 300 mg nocte and cimetidine 800 mg nocte has been carried out in 1677 patients with endoscopically verified duodenal ulcer disease. Fifty-three percent of ulers healed by two weeks during treatment with ranitidine 300 mg pem and 88% by four weeks, while the results for ranitidine 300 mg nocte were 50% and 86%, respectively, and 44% and 84% for cimetidine. The difference between ranitidine 300 mg pem and cimetidine was significant at two weeks (P = 0.002, Mantel-Haenszel chi-squared test). The relative efficacy of the treatments was not dependent upon gender, smoking habit, alcohol intake, or ulcer frequency. However, the overall differences in healing between patients with small and large ulcers and patients with single and multiple ulcers were significantly different at weeks 2 and 4 (P < 0.001). Significantly more patients treated with ranitidine (60%) had complete relief of epigastric pain than those treated with cimetidine (54%) (P < 0.05). A meta-analysis of the four double-blind comparisons of ranitidine 300 mg pem (N = 841) and 300 mg nocte (N = 849), including the present study, failed to show the benefits of pem dosing, predicted from pharmacological studies.     

Triple therapy with sucralfate is not effective in eradicating Helicobacter pylori and does not reduce duodenal ulcer relapse rates

OBJECTIVES: The most used therapeutic schedule to eradicate Helicobacter pylori is the "triple therapy," which is based on the simultaneous use of a bismuth salt and two antibiotics. Sucralfate, a basic aluminum salt of sucrose sulfate, is supposed to have an antibacterial activity and is said to reduce the bacterial density of H. pylori. This randomized, prospective clinical trial compares the efficacy of an alternative oral triple therapy consisting of sucralfate, tinidazol, and tetracycline with a conventional therapy using ranitidine, with respect to H. pylori eradication and duodenal ulcer healing and recurrence in a 12-month follow-up. METHODS: Forty-three patients with active duodenal ulcers diagnosed at endoscopy were enrolled to receive either 1 g of sucralfate four times daily for 30 days, 500 mg of tetracycline four times daily, and 500 mg of tinidazol three times daily, for 10 days (group A; n = 23) or 150 mg of ranitidine twice daily for 30 days (group B; n = 20). The groups were age- and sex-matched and balanced for tobacco use and H. pylori status. Compliance assessed by post-treatment interviews was considered high (all patients declared that they had ingested at least 80% of the drugs). RESULTS: Both therapies were efficient in healing ulcers (group A, 95%; group B, 90%), the relapse rates were high in both groups (group A, 77%; group B, 89%), and the alternative triple therapy eradicated H. pylori in only 4% of the patients. CONCLUSION: Alternative oral triple therapy presented no significant advantage over ranitidine treatment of active ulcer disease.     

Problems with parsimony in sequences of biased base composition

In almost all eradication regimens, which contain antibiotics and bismuth derivatives, the administration of acid suppressing drugs for 4-6 weeks is recommended for healing of duodenal ulcer. The aim of this multicenter double blind study is to elucidate the effect of two classic antibiotics tetracycline (CAS 60-54-8) and metronidazole (CAS 443-48-1) alone or combined with ranitidine (CAS 66357-35-5) on the healing of duodenal ulcer and eradication of Helicobacter Pylori. Patients with duodenal ulcer were randomized to two treatment groups: group A received either ranitidine 4 x 150 mg or tetracycline 4 x 500 mg or metronidazole 3 x 250 mg for 2 weeks. Group B received 4 x placebo + tetracycline and metronidazole as in group A for 2 weeks. A final endoscopy was performed after 8 weeks. Four biopsy specimens were obtained from the antrum (two) and corpus (two) for both urease test and hematoxylin stain for detection of H. pylori. Out of 201 patients entering the study 156 completed the study (78 in A and 78 in B). The healing rate of duodenal ulcer was 98.7% in group A and 97.5 in group B. The eradication rate was only 33.3% in group B but 64% in group A (p < 0.001), when additionally ranitidine was given. The present study shows that treatment with the two antibiotics tetracycline and metronidazole alone results in a very low H. pylori eradication, but almost complete healing of duodenal ulcer after 8 weeks. Prolonged administration of antisecretory drugs in eradication regimens containing two antibiotics is not necessary for duodenal ulcer healing. However, the addition of H2-receptor antagonists or proton pump inhibitors to antibiotics increases the eradication rate.     

Increase of serum tumor marker concentrations by interferon-alpha

BACKGROUND: The effect of infection by Helicobacter pylori on gastric physiology in duodenal ulcer subjects is controversial. There is evidence that the infection is associated with abnormalities in gastrin homeostasis. Consistent changes in pentagastrin-stimulated acid secretory status have proved difficult to establish. This may be because patients have been studied too soon after Helicobacter pylori eradication. AIMS: To study the immediate and longer term effect of Helicobacter pylori eradication on basal and pentagastrin-stimulated acid secretion in duodenal ulcer subjects. PATIENTS AND METHODS: Patients with active duodenal ulcer disease were studied. Ulcers were healed with sucralfate 2 g bd or ranitidine 300 mg nocte. Helicobacter pylori eradication was attempted with bismuth-based "Triple Therapy", and the nine patients in whom the organism was successfully eradicated were followed and studied over the 12-month period. Acid secretion was studied at entry (prior to the initiation of therapy), following healing, following eradication and 12 months later. Basal, low dose (0.1 microgram/kg) and high dose (6 micrograms/kg) pentagastrin-stimulated acid secretion was determined. RESULTS: Whilst there was a tendency for basal and low dose-stimulated acid secretion to fall following eradication, in this study only the reduction in high dose-stimulated acid secretion achieved significance following eradication (entry mean = 59.6, post eradication mean = 49.6, p < 0.03). This effect of eradication on high dose pentagastrin-stimulated acid secretion was also seen at the 12-month study (mean = 48.9, p < 0.02 versus entry). CONCLUSION: The findings of this study suggests that maximally stimulated acid secretion is modestly, albeit significantly, reduced following Helicobacter pylori eradication and that this effect persists.     

Acid suppression with ranitidine plus oral triple therapy improves ulcer healing but not Helicobacter pylori eradication

BACKGROUND/AIMS: To evaluate whether the addition of 2 weeks of ranitidine to a 1-week oral triple therapy (OTT) regimen improved ulcer healing and H. pylori eradication. METHODOLOGY: Two hundred and eleven consecutive patients with an endoscopic diagnosis of active duodenal ulcer (DU) and a positive antrum biopsy for H. pylori were enrolled. Those attending the Hospital Vera Cruz (Group A, n=142) received a 14-day course of ranitidine (150 mg after breakfast and dinner) plus a 1-week OTT, consisting of bismuth subcitrate, (240 mg after the 3 meals), tetracycline (500 mg, 10 min before the three meals and at bedtime), and furazolidone (200 mg after breakfast and dinner). Patients from the Hospital das Clinicas (Group B, n=69) received the same OTT as Group A but without ranitidine. Patients underwent endoscopy again on average 40 days (range: 30-60 days) after completing therapy in order to assess ulcer healing and H. pylori status. RESULTS: Both schedules were equally efficient in eradicating H. pylori with 90% (128/142) eradication in group A, and 84% (58/69) in group B (p=0.2). In contrast, the addition of ranitidine to OTT improved ulcer healing when compared with OTT alone (96%, 137/142, vs. 70%, 48/69; p<0.001). CONCLUSIONS: Our results demonstrate that the association of acid suppression, obtained with 2 week ranitidine administration with OTT improved ulcer healing but did not enhance H. pylori eradication.     

One-week use of ranitidine bismuth citrate, amoxycillin and clarithromycin for the treatment of Helicobacter pylori-related duodenal ulcer

BACKGROUND: Proton pump inhibitors have been widely used in combination with amoxycillin, clarithromycin or metronidazole for the treatment of Helicobacter pylori infection. AIM: To study the effects of 1-week ranitidine bismuth citrate (RBC)-based triple therapy in the treatment of H. pylori-related duodenal ulcers. METHOD: Patients with duodenal ulcers and H. pylori infection were prospectively randomized to receive either RBC with amoxycillin and clarithromycin for 1 week (RAC), or omeprazole with amoxycillin and clarithromycin for 1 week (OAC). No additional ulcer healing drug was used after the 1-week medication. Patients were assessed for H. pylori eradication, ulcer healing and side-effects after receiving the therapies. RESULTS: One hundred consecutive patients were recruited to this study, with 50 patients randomized to each treatment group. In the intention-to-treat analysis, duodenal ulcers were completely healed in 45 (90%) patients in the RAC group and 43 (89.6%) in the OAC group (P = 1.0). H. pylori eradication was confirmed in 47 (94%) in the RAC group and 42 (87.5%) in the OAC group (P = 0.31). There was no significant difference in the severity of side-effects experienced by the two treatment groups. CONCLUSION: One-week RBC-based triple therapy is an effective treatment for H. pylori-related duodenal ulcers. The therapeutic effects are comparable to a 1-week course of proton pump inhibitor-based triple therapy.     

Triple therapy in duodenal ulcer healing--a follow up study

Thirty-nine Helicobacter pylori (HP) positive chronic duodenal ulcer patients completed the 4 weeks treatment of triple therapy (Denol, Metronidazole and Amoxil). Of these 29 showed healed duodenal ulcer and negative CLO test at 8 weeks (eradication). They were followed at 3,6 and 12 months and at each follow-up, endoscopy and CLO testing were repeated. At 12 weeks, 54% showed a healed ulcer and negative CLO and these figures reached to 69 and 66% at 6 and 12 months respectively. Thirty percent relapsed within 1 year. The present study indicates a prolonged remission of duodenal ulcer following HP eradication.     

Cost-effectiveness analysis of the eradication of Helicobacter pylori as treatment for duodenal ulcer

OBJECTIVE: To assess the cost-effectiveness of H. pylori eradication in patients with duodenal ulcer in Spain. METHODS: A decision model was used to compare the cost per cured patient and the cost per patient without recurrence in one year for four treatment strategies: 1) intermittent antisecretory therapy, 2) initial antisecretory therapy and H. pylori eradication if ulcer recurrence, 3) initial H. pylori eradication with antibiotics and antisecretory drugs, 4) antisecretory therapy followed by continuous maintenance therapy with ranitidine. Clinical variables were obtained from published studies made in Spain. RESULTS: Initial H. pylori eradication is the cheapest strategy (74,702-82,028 ptas per cured patient) and the most effective (83.3-85.2% patients without recurrence in one year). Intermittent antisecretory therapy is one of the most expensive (94,891-105,324 ptas per cured patient) and the less effective (12% patients without recurrence in one year). CONCLUSION: Initial eradication of H. pylori is the treatment of choice in patients with duodenal ulcer.     

Factors affecting serum selenium and vitamin E concentrations in dairy cows

Supplementation of selenium and vitamin E to enhance disease resistance in dairy cattle has become common, particularly to prevent periparturient reproductive disorders and mastitis. To establish reference values for serum vitamin E and selenium concentrations in postparturient dairy cattle and to determine whether serum concentrations of these micronutrients varied with season and stage of lactation, cows from a stratified random sample of 50 herds were studied for 1 year. Blood samples were collected from each of the 50 study herds twice, from the 10 most recently parturient cows or from 10% of the herd, whichever was greatest. Mean concentration of vitamin E and selenium was 2.55 micrograms/ml and 78.12 ng/ml, respectively. Vitamin E concentrations were significantly (P < 0.05) higher during the summer and fall than during the winter and spring. Selenium concentrations were significantly (P < 0.05) lower during the summer and fall than during the winter and spring. Herd, season of blood sample collection, and time since parturition were significant (P < 0.02) in explaining variation in vitamin E and selenium concentrations.     

CT in Fournier''s gangrene

BACKGROUND: Few outcome studies directly compare Helicobacter pylori eradication therapy with maintenance H2-antagonist therapy in duodenal ulcer disease. AIM: To examine prospectively the efficacy of H. pylori eradication therapy with ranitidine maintenance therapy over 1 year in patients with confirmed chronic duodenal ulcer. METHODS: One hundred and nineteen patients with active H. pylori infection were randomized to receive ranitidine, 150 mg/day initially (58 patients), or omeprazole, 40 mg/day, amoxycillin 2 g/day and metronidazole 1.2 g/day for 14 days, or omeprazole 40 mg/day and clarithromycin 1.5 g/day, for 14 days (if penicillin-allergic). Symptoms were assessed using the Gastrointestinal System Rating Scale (GSRS) and SF36 quality of life index. RESULTS: 13C urea breath testing confirmed overall treatment success in 100% of patients (58/58) per protocol and 95.1% (58/61) on an intention-to-treat basis. At 4 and 12 months there were no differences in any GSRS symptoms between treatment groups. SF36 analysis showed a perceived health improvement at 4 and 12 months in patients who received H. pylori eradication. However, despite successful H. pylori eradication, one-fifth of patients still required antisecretory therapy. CONCLUSION: Following successful H. pylori eradication, chronic duodenal ulcer patients were at least as well symptomatically as when taking maintenance ranitidine. They perceived that their health had improved, but a subgroup was still acid-suppression dependent.     

Sex differences in seasonal variations in P300

Previous reports of seasonal variations in P300 were based on cross-sectional observations of subjects tested at different times of the year. In this study, we tested three groups of subjects in each of two seasons: winter and spring, spring and summer, and summer and winter. We found winter or spring maxima in auditory and visual P300 and visual slow wave. This pattern of results, with the amplitude of P300 being inversely related to the amount of sunlight in a season, supports the hypothesis that the allocation of processing resources varies across the seasons. Our results also suggest a trend for an increased sensitivity of women, as compared with men, to seasonal influences on P300. Although our findings do not provide strong evidence that P300 varies systematically as a function of season, seasonal factors appear to affect cognitive processing (as indexed by P300) differentially in men and women.