GP consultations for menstrual disorders after COVID-19 vaccination - A self-controlled cohort study based on routine healthcare data from the Netherlands.

INTRODUCTION: Several studies described that COVID-19 vaccinations can cause menstrual disorders. Our study aimed to describe whether this also resulted in more general practitioner (GP) consultations for menstrual disorders after COVID-19 vaccination, based on a large cohort study. METHODS: A retrospective self-controlled cohort study was performed including vaccinated women in 2021 aged 12-49 years from two large, representative GP databases in the Netherlands. Incidence rates and incidence rate ratio's (IRR) were calculated using Poisson regression, adjusting for SARS-CoV-2 infection as time-varying confounder. The exposed period was set at maximum six months after each COVID-19 vaccination and the non-exposed period was defined as all-time outside the exposed period. RESULTS: The cohort included 631,802 women, of which 18,986 (3 %) consulted the GP for a menstrual disorder during 2021. Increased GP consultations were observed among 12-14 year olds for amenorrhea/hypomenorrhea/oligomenorrhea (IRR: 1.85, 95 % CI: 1.30-2.65) and irregular/frequent menstruation (IRR: 1.33, 95 % CI: 1.06-1.69) after COVID-19 vaccination in general, and after Pfizer/BioNTech vaccination (IRR: 1.87, 95 % CI: 1.31-2.67 for amenorrhea/hypomenorrhea/oligomenorrhea and IRR: 1.35, 95 % CI: 1.06-1.70 for irregular/frequent menstruation). Persons from this age group were in general also vaccinated with Pfizer/BioNTech. No increase in the frequency of GP consultations were observed for older age groups, other vaccine brands, and potential risk groups. CONCLUSION: For the majority of women, no increased GP consultations for menstrual disorders was found. Solely for the youngest age group (12-14 year olds) increased GP consultations for specific types of menstrual disorders was found after Pfizer/BioNTech vaccination.

An innovative method to strengthen evidence for potential drug safety signals using Electronic Health Records.

Reports from spontaneous reporting systems (SRS) are hypothesis generating. Additional evidence such as more reports is required to determine whether the generated drug-event associations are in fact safety signals. However, underreporting of adverse drug reactions (ADRs) delays signal detection. Through the use of natural language processing, different sources of real-world data can be used to proactively collect additional evidence for potential safety signals. This study aims to explore the feasibility of using Electronic Health Records (EHRs) to identify additional cases based on initial indications from spontaneous ADR reports, with the goal of strengthening the evidence base for potential safety signals. For two confirmed and two potential signals generated by the SRS of the Netherlands Pharmacovigilance Centre Lareb, targeted searches in the EHR of the Leiden University Medical Centre were performed using a text-mining based tool, CTcue. The search for additional cases was done by constructing and running queries in the structured and free-text fields of the EHRs. We identified at least five additional cases for the confirmed signals and one additional case for each potential safety signal. The majority of the identified cases for the confirmed signals were documented in the EHRs before signal detection by the Dutch Medicines Evaluation Board. The identified cases for the potential signals were reported to Lareb as further evidence for signal detection. Our findings highlight the feasibility of performing targeted searches in the EHR based on an underlying hypothesis to provide further evidence for signal generation.

The role of co-morbidities in the development of an AEFI after COVID-19 vaccination in a large prospective cohort with patient-reported outcomes in the Netherlands.

BACKGROUND: The effect of a preexisting comorbidity on the occurrence of adverse events after immunization (AEFIs) has been studied poorly. In this longitudinal cohort study, we assess the association between co-morbidities and the occurrence of AEFIs after COVID-19 vaccination. Also, we described the occurrence of flare-ups and their manifestation after COVID-19 vaccination in people with rheumatic diseases. RESEARCH DESIGN AND METHODS: We performed multivariable logistic regression to investigate the association between the occurrence of AEFIs and 10 common comorbidities using patient-reported data from people vaccinated with the AstraZeneca, Johnson&Johnson, Moderna, or Pfizer vaccine. RESULTS: Occurrence of any AEFI, injection site reactions, headache, fatigue, and/or malaise was significantly associated with presence of comorbidities, including psychological disorders, musculoskeletal disorders, and endocrine disorders after the first and second doses (OR ranges 1.23-1.77). One participant with rheumatoid arthritis experienced a flare-up after receiving the first dose of the AstraZeneca vaccine. DISCUSSION/CONCLUSION: The results showed that the odds of reporting an AEFI after COVID-19 vaccination is significantly higher in the presence of some comorbidities whilst flare-ups are uncommon after receiving COVID-19 vaccination in people with rheumatic disease. In-depth research is needed to validate our results and unravel the observed associations from a mechanistic perspective.

[Clioquinol use for Dientamoeba fragilis infections is questionable]. / Clioquinol voor Dientamoeba fragilis-infectie discutabel.

Clioquinol is used for treatment of amoebiasis and infection with Dientamoeba fragilis. In a guideline of the Dutch Working Party on Antibiotic Policy, clioquinol is recommended as a first-choice treatment for Dientamoeba fragilis. This drug, however, is associated with subacute myelo-optico-neuropathy (SMON). It was withdrawn from the market worldwide in 1985 by manufacturer Ciba-Geigy. Although the Dutch Medicines Evaluation Board has registered no products for systemic use of clioquinol since then, the drug is available as a pharmacy-compounded drug and the last few years the use of clioquinol in the Netherlands has risen again. The Netherlands Pharmacovigilance Centre Lareb has received a growing number of reports of adverse drug reactions (ADRs) associated with the use of clioquinol, including nervous system disorder ADRs occurring at recommended dosages. Therefore, we debate the use of clioquinol as a first-choice treatment option for Dientamoeba fragilis.

Pharmacologically effective red yeast rice preparations marketed as dietary supplements illustrated by a case report.

This paper reports a typical statin-related adverse reaction from a red yeast rice (RYR) supplement and the analytical findings from the supplement. It also examines the regulatory framework governing botanical supplements in Europe. Two key events that shaped the current regulatory framework are reviewed. First, the Hecht-Pharma judgement by the European Court of Justice (ECJ) that inverted the precautionary principle in the Medicines Act to a reactionary principle. Following the Hecht-Pharma judgement, pharmacological active dietary supplements can be sold until sufficient signals of harm show that they are an unregistered medicine, placing a huge burden on regulatory authorities. Secondly, the European Food Safety Authority (EFSA) in 2011 approved the first health claim for pharmacologically active RYR dietary supplements. If the current regulatory status for pharmacologically active RYR dietary supplements does not permit adequate warning and active monitoring of adverse drug reactions, then the current regulatory framework may not be adequate to ensure consumer safety.Copyright © 2016 John Wiley & Sons, Ltd.

Reflections after the Diane affair.

The Pharmacovigilance Centre Lareb received 621 reports of possible adverse drugs reactions on Diane-35® . Of all reports, 388 were received after media attention. Of the 309 reports of thromboembolic adverse drugs reactions, 18 cases were fatal. In 31 cases the thromboembolic adverse drugs reaction was initially not recognized as such. The analysis and the turmoil of the 'Diane affair' gave rise to the following reflections: Reflection 1. Continuous awareness and attention of risk of medicines is needed, also for known risks, for timely recognition of adverse drugs reactions. Reflection 2. Reporting side effects should be part of the professional attitude. Reports play a pivotal role in the detection of new adverse drugs reactions and the conditions under which known adverse drugs reactions occur. Reflection 3. Improvement of adequate use of drugs. Pharmacovigilance not only has the aim to improve knowledge on risk of medicines, but also the aim of getting this knowledge into Health Care practice.

Acute effects of nicotine on attention and response inhibition.

Smoking is highly prevalent among patients with Attention Deficit Hyperactivity Disorder (ADHD). Previous studies using the reversed continuous performance task (R-CPT) have suggested that nicotine reduces inattention. Since especially adults with ADHD have been claimed to suffer from a core deficit in inhibitory control, this study aimed at determining whether nicotine improves response inhibition in addition to attention. Sixteen healthy regular smokers participated in a pre/post treatment design in which transdermal patches containing 7 and 21 mg nicotine per day were administered in a counterbalanced, double-blind manner. In a second study, patches containing 0 mg (placebo) and 21 mg per day were administered to a different group of regular smokers. For replication purposes, the R-CPT and the profile of mood states (POMS) were administered. Furthermore, a different version of the continuous performance task (CPT-AX) and the stop-signal task, traditionally used to measure response inhibition, were presented. The high dose of nicotine was found to relieve self-reported Depression in Study 1 and Fatigue in Study 2. Performance data indicated acute effects of nicotine on attention-related, but not on inhibition-related measures. Especially the comparison with placebo revealed decreases in reaction time and variability of responding. The results imply that patients with ADHD smoke to reduce inattention.

Pedophilia is accompanied by increased plasma concentrations of catecholamines, in particular epinephrine.

Plasma epinephrine and norepinephrine concentrations were measured in pedophiles and normal men both in placebo conditions and after administration of meta-chlorophenylpiperazine (mCPP), a post-synaptic 5-HT2 receptor agonist. The plasma concentrations of catecholamines, in particular epinephrine, were significantly increased in pedophiles. It is concluded that pedophiles may have an increased activity of the sympathoadrenal system.

Lower baseline plasma cortisol and prolactin together with increased body temperature and higher mCPP-induced cortisol responses in men with pedophilia.

There is some evidence that hormonal and serotonergic alterations may play a role in the pathophysiology of paraphilias. The aims of the present study were to examine: 1) baseline plasma cortisol, plasma prolactin, and body temperature; and 2) cortisol, prolactin, body temperature, as well as behavioral responses to meta-chlorophenylpiperazine (mCPP) and placebo in pedophiles and normal men. Pedophiles showed significantly lower baseline plasma cortisol and prolactin concentrations and a higher body temperature than normal volunteers. The mCPP-induced cortisol responses were significantly greater in pedophiles than in normal volunteers. In normal volunteers, mCPP-induced a hyperthermic response, whereas in pedophiles no such response was observed. mCPP induced different behavioral responses in pedophiles than in normal men. In pedophiles, but not in normal men, mCPP increased the sensations "feeling dizzy, " "restless," and "strange" and decreased the sensation "feeling hungry". The results suggest that there are several serotonergic disturbances in pedophiles. It is hypothesized that the results are compatible with a decreased activity of the serotonergic presynaptic neuron and a 5-HT2 postsynaptic receptor hyperresponsivity.

Serotonergic markers and lowered plasma branched-chain-amino acid concentrations in fibromyalgia.

The aims of the present study were to examine serotonergic markers, i.e. [3H]paroxetine binding characteristics and the availability of plasma tryptophan, the precursor of serotonin (5-HT), and the plasma concentrations of the branched chain amino acids (BCAAs), valine, leucine and isoleucine, in fibromyalgia. The [3H]paroxetine binding characteristics, B(max) and K(d) values, and tryptophan and the competing amino acids (CAA), known to compete for the same cerebral uptake mechanism (i.e. valine, leucine, isoleucine, phenylalanine and tyrosine), were determined in fibromyalgia patients and normal controls. There were no significant differences in the [3H]paroxetine binding characteristics (B(max) and K(d)) between fibromyalgia and control subjects. There were no significant differences in plasma tryptophan or the tryptophan/CAA ratio between fibromyalgia patients and normal controls. In the fibromyalgia patients, there were no significant correlations between [3H]paroxetine binding characteristics or the availability of tryptophan and myalgic or depressive symptoms. Patients with fibromyalgia had significantly lower plasma concentrations of the three BCAAs (valine, leucine and isoleucine) and phenylalanine than normal controls. It is hypothesized that the relative deficiency in the BCAAs may play a role in the pathophysiology of fibromyalgia, since the BCAAs supply energy to the muscle and regulate protein synthesis in the muscles. A supplemental trial with BCAAs in fibromyalgia appears to be justified.

The immune-inflammatory pathophysiology of fibromyalgia: increased serum soluble gp130, the common signal transducer protein of various neurotrophic cytokines.

Fibromyalgia is a chronic, painful musculoskeletal disorder characterized by widespread pain, pressure hyperalgesia, morning stiffness and by an increased incidence of depressive symptoms. The etiology, however, has remained elusive. The aim of the present study was to examine the inflammatory response system (IRS) in fibromyalgia. Serum interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), sgp130, sIL-1R antagonist (IL-1RA) and sCD8 were determined in 33 healthy volunteers and in 21 fibromyalgia patients, classified according to the American College of Rheumatology criteria. Severity of illness was measured with several pain scales, dolorimetry and the Hamilton Depression Rating Scale (HDRS). Serum sgp130 was significantly higher and serum sCD8 significantly lower in fibromyalgia patients than in healthy volunteers. Serum sIL-6R and sIL-1RA were significantly higher in fibromyalgia patients with an increased HDRS score (> or = 16) than in normal volunteers and fibromyalgia patients with a HDRS score < 16. In fibromyalgia patients, an important part of the variance in sCD8 (50.3%) and IL-1RA (19.3%) could be explained by the HDRS score; 74.3% of the variance in sIL-6R was explained by the combined effects of pain symptoms and the HDRS score; and 25.9% of the variance in serum sgp130 was explained by stiffness. The results support the contention that pain and stiffness in fibromyalgia may be accompanied by a suppression of some aspects of the IRS and that the presence of clinically significant depressive symptoms in fibromyalgia is associated with some signs of IRS activation.

Pindolol and mianserin augment the antidepressant activity of fluoxetine in hospitalized major depressed patients, including those with treatment resistance.

The aims of this study were to examine whether pindolol, a serotonin (5-hydroxytryptamine [5-HT])-1A receptor antagonist, and mianserin, a 5-HT2A/C and alpha2-adrenoceptor (alpha2-AR) antagonist, may augment the clinical efficacy of fluoxetine, a selective serotonin reuptake inhibitor, and shorten the latency of onset of antidepressive activity in the treatment of major and treatment-resistant depression (TRD). Ten days after admission to the hospital, 31 major depressed patients were randomly assigned using a double-blind, controlled design to receive fluoxetine 20 mg daily, fluoxetine 20 mg daily plus pindolol 7.5 mg daily, or fluoxetine 20 mg plus mianserin 30 mg daily for 5 weeks. The 17-item Hamilton Rating Scale for Depression (HAM-D) score was the primary outcome measure. Analysis of efficacy was conducted according to the intent-to-treat analysis principle considering the change from baseline to endpoint. It was found that fluoxetine plus pindolol and fluoxetine plus mianserin were significantly more effective than fluoxetine alone. Using an outcome measure of 50% reduction in the HAM-D, a 60% response rate was found in patients treated with either fluoxetine plus pindolol or fluoxetine plus mianserin compared with a 9% response rate in patients treated with fluoxetine alone. The HAM-D score 1 week after starting fluoxetine plus mianserin decreased more than 4 points and was significantly greater than that obtained by fluoxetine alone. The results suggest that pindolol and mianserin augment the efficacy of fluoxetine in the treatment of TRD and that mianserin, but not pindolol, may significantly shorten the latency of onset of antidepressive action when combined with fluoxetine.

Increased 24-hour urinary cortisol excretion in patients with post-traumatic stress disorder and patients with major depression, but not in patients with fibromyalgia.

There is now firm evidence that major depression is accompanied by increased baseline activity of the hypothalamic-pituitary-adrenal (HPA) axis, as assessed by means of 24-h urinary cortisol (UC) excretion. Recently, there were some reports that fibromyalgia and post-traumatic stress disorder (PTSD), two disorders which show a significant amplitude of depressive symptoms, are associated with changes in the baseline activity of the HPA axis, such as low 24-h UC excretion. The aim of the present study was to examine 24-h UC excretion in fibromyalgia and PTSD patients compared to normal controls and patients with major depression. In the three patient groups, severity of depressive symptoms was measured by means of the Hamilton Depression Rating Scale (HDRS) score. Severity of fibromyalgia was measured using a dolorimetrically obtained myalgic score, and severity of PTSD was assessed by means of factor analytical scores computed on the items of the Composite International Diagnostic Interview (CIDI), PTSD Module. Patients with PTSD and major depression had significantly higher 24-h UC excretion than normal controls and fibromyalgia patients. At a threshold value of > or = 240 micrograms/24 h, 80% of PTSD patients and 80% of depressed patients had increased 24 h UC excretion with a specificity of 100%. There were no significant differences in 24-h UC excretion either between fibromyalgia patients and normal controls, or between patients with major depression and PTSD patients. In the three patient groups, no significant correlations were found between 24-h UC excretion and the HDRS score. In fibromyalgia, no significant correlations were found between 24-h UC excretion and the myalgic score. In PTSD, no significant correlations were found between 24-h UC excretion and severity of either depression-avoidance or anxiety-arousal symptoms. In conclusion, this study found increased 24-h UC excretion in patients with PTSD comparable to that in patients with major depression, whereas in fibromyalgia no significant changes in 24-h UC were found.

Influence of academic examination stress on hematological measurements in subjectively healthy volunteers.

Some recent reports showed that a brief exposure to a mental stressor during 3-20 min may induce hematological changes in humans. The aim of the present study was to examine the effects of academic examination stress on erythron variables, such as the number of red blood cells (RBC), hemoglobin (Hb), hematocrit (Ht), mean corpuscular volume (MCV), mean cell Hb (MCH), mean cell Hb concentration (MCHC), RBC distribution width (RDW), and serum iron and transferrin (Tf). The above variables were determined in 41 students in three conditions, i.e. the stress condition (the day before a difficult oral exam) and two baseline conditions, i.e. a few weeks earlier and later. At the same occasions, subjects completed the Perceived Stress Scale (PSS), the state version of the State-Trait Anxiety Inventory (STAI) and the Profile of Mood States (POMS). Academic examination stress significantly increased Ht, Hb, MCV, MCH and MCHC and significantly decreased RDW. There were significant relationships between the stress-induced changes in the PSS, STAI and POMS scores and those in Ht, Hb, MCV and MCH (allpositive) and RDW (negative). It is concluded that academic examination stress induces significant hematological changes indicative of an increased number of large RBC and increased hemoglobinisation, which cannot be explained by shifts of fluid out of the intravascular space, concentrating non-diffusible blood constituents.

Lower serum activity of prolyl endopeptidase in fibromyalgia is related to severity of depressive symptoms and pressure hyperalgesia.

BACKGROUND: The aims of the present study were to examine serum activities of peptidases, i.e. prolyl endopeptidase (PEP) and dipeptidyl peptidase IV (DPP IV), in patients with fibromyalgia and to examine the effects of subchronic treatment with sertraline on these variables. METHOD: Serum PEP and DPP IV activity were measured in 28 normal volunteers and 21 fibromyalgia patients, classified according to the American College of Rheumatology criteria. Tenderness at tender points was evaluated by means of dolorimetry. Fibromyalgia patients had repeated measurements of serum PEP and DPP IV both before and after repeated administration of sertraline or placebo for 12 weeks. RESULTS: Patients with fibromyalgia had significantly lower serum PEP activity than normal volunteers. There were significantly negative correlations between serum PEP activity and severity of pressure hyperalgesia and the non-somatic, cognitive symptoms of the Hamilton Depression Rating Scale. Fibromyalgia patients with severe pressure hyperalgesia had significantly lower PEP activity than normal controls and fibromyalgia patients with less severe hyperalgesia. Fibromyalgia patients with severe non-somatic depressive symptoms had significantly lower serum PEP activity than normal volunteers. There were no significant changes in serum DPP IV activity in fibromyalgia. There were no significant effects of repeated administration of sertraline on serum PEP and DPP IV activity in patients with fibromyalgia. CONCLUSIONS: The results show that fibromyalgia, and aberrant pain perception and depressive symptoms in fibromyalgia are related to lower serum PEP activity. It is hypothesized that lower serum PEP activity may play a role in the biophysiology of fibromyalgia through diminished inactivation of algesic and depression-related peptides.

Auditory event related potentials in major depression: prolonged P300 latency and increased P200 amplitude.

BACKGROUND: Some studies have shown disturbances in auditory event related potentials (AERPs) in patients with major depression. METHODS: In this exploratory study, the late AERP components, N100 (latency), P200 (amplitude and latency) and P300 (amplitude and latency) were recorded in 68 subjects, i.e. 39 major depressed subjects, with (n=4) or without (n=35) cognitive deterioration, 18 patients with Alzheimer's dementia (SDAT) and 11 normal volunteers. Twenty-five major depressed patients had repeated measurements of AERPs both before and after treatment with antidepressants. RESULTS: Major depressed subjects without cognitive deterioration had significantly higher P300 latency and P200 amplitude than normal volunteers. SDAT patients and major depressed patients with cognitive impairment had a significantly higher P300 latency than depressed patients without cognitive impairment. In the latter, no significant alterations in any of the AERP components upon subchronic treatment with antidepressants were recorded. Nonresponders to antidepressant therapy had significantly higher pretreatment P300 latency and P200 amplitude than responders to treatment (P=0.006) and normal volunteers (P=0.0004). CONCLUSIONS: The findings may suggest that delayed P300 latency as well as increased P200 amplitude accompany major depression and may predict a nonresponse to subsequent antidepressive therapy.

The influence of psychological stress on total serum protein and patterns obtained in serum protein electrophoresis.

BACKGROUND: Significant alterations in total serum protein (TSP) patterns obtained in serum protein electrophoresis and serum proteins have been reported in patients with major depression and in subjects submitted to a combination of psychological and physical stress. The aim of the present study was to examine the effects of academic examination stress, on TSP and patterns obtained in serum protein electrophoresis. METHODS: TSP and the concentrations and percentages of the major electrophoretically separated serum proteins were measured in 41 healthy biomedical students the day before a difficult academic examination (i.e. the stressful condition), as well as a few weeks before and after the stressful condition (i.e. two baseline conditions). RESULTS: Academic examination stress increased TSP and the alpha 1, alpha 2, beta and gamma concentrations in stress-reactors, but not in stress non-reactors (as defined by changes in the Perceived Stress Scale). Academic examination stress reduced the percentage of albumin in the stress-reactors, but not in stress non-reactors. There were significant positive relationships between the stress-induced changes in TSP and serum alpha 2, beta and gamma concentrations and the stress-induced changes in the Perceived Stress Scale. CONCLUSIONS: The results show that even mild psychological stress of short duration can lead to measurable changes in TSP and in patterns obtained in serum protein electrophoresis.

Immune markers in fibromyalgia: comparison with major depressed patients and normal volunteers.

BACKGROUND: There is a high degree of comorbidity between fibromyalgia and major depression. The latter is characterized by signs of immune activation, whereas the immune status in fibromyalgia is not yet elucidated. The aims of the present study were to examine (i) neopterin and biopterin excretion in 24-h urine of patients with fibromyalgia compared with normal volunteers and patients with major depression; and (ii) the effects of subchronic treatment with sertraline (11 weeks) on the urinary excretion of neopterin and biopterin. METHODS: Measurements of neopterin, biopterin, pseudouridine, creatinine and uric acid in 24-h urine were performed by means of HPLC in 14 fibromyalgia and ten major depressed patients and 17 normal volunteers. RESULTS: There were no significant differences in urine excretion of the above five analytes between patients with fibromyalgia and normal volunteers. Patients with major depression showed significantly higher urinary neopterin excretion than normal volunteers and fibromyalgia patients. Patients with fibromyalgia and major depression had a significantly increased neopterin/creatinine ratio. Fibromyalgia patients had significantly lower urinary excretion of creatinine than patients with major depression. In fibromyalgia patients, there were no significant effects of sertraline treatment on any of the urine analytes. CONCLUSIONS: The findings suggest that fibromyalgia, in contrast to major depression, may not be accompanied by activation of cell-mediated immunity. LIMITATION: Other immune markers should be measured in fibromyalgia before drawing definite conclusions. CLINICAL RELEVANCE: Increased urinary excretion of neopterin can be used as a marker for major depression, but not fibromyalgia.

Serotonin-immune interactions in major depression: lower serum tryptophan as a marker of an immune-inflammatory response.

Serum total tryptophan and the five competing amino acids (CAA), i.e., valine, leucine, tyrosine, phenylalanine, and isoleucine were determined in 35 major depressed subjects of whom 27 with treatment resistant depression (TRD), and 15 normal controls. Twenty-five of the depressed subjects had repeated measurements of the amino acids both before and after antidepressive treatment. The following immune-inflammatory variables were assayed in the above subjects: serum zinc (Zn), total serum protein (TSP), albumin (Alb), transferrin (Tf), iron (Fe), high-density lipoprotein cholesterol (HDL-C), number of peripheral blood leukocytes, and the CD4+/CD8+ T cell (T-helper/T-suppressor) ratio. Serum tryptophan and the tryptophan/CAA ratio were significantly lower in major depressed subjects than in normal controls. The tryptophan/CAA ratio was significantly lower in patients with TRD than in patients without TRD and normal controls. There were no significant alterations in any of the amino acids upon successful therapy. There were significant correlations between serum tryptophan and serum Zn, TSP, Alb, Tf, Fe, and HDL-C (all positive), and number of leukocytes and the CD4+/CD8+ T-cell ratio (all negative). The tryptophan/CAA ratio was significantly and negatively related to the number of leukocytes and the CD4+/CD8+ T-cell ratio. The results suggest that (a) TRD is characterized by lower availability of serum tryptophan; (b) the availability of tryptophan may remain decreased despite clinical recovery; and (c) the lower availability of tryptophan is probably a marker of the immune-inflammatory response during major depression.