Evaluation of a novel ELISA for serotonin: urinary serotonin as a potential biomarker for depression.

Depression is a common disorder with physical and psychological manifestations often associated with low serotonin. Since noninvasive diagnostic tools for depression are sparse, we evaluated the clinical utility of a novel ELISA for the measurement of serotonin in urine from depressed subjects and from subjects under antidepressant therapy. We developed a competitive ELISA for direct measurement of serotonin in derivatized urine samples. Assay performance was evaluated and applied to clinical samples. The analytical range of the assay was from 6.7 to 425 µg serotonin/g creatinine (Cr). The limit of quantification was 4.7 µg/g Cr. The average recovery for spiked urine samples was 104.4%. Average intra-assay variation was 4.4%, and inter-assay variation was <20%. The serotonin analysis was very specific. No significant interferences were observed for 44 structurally and nonstructurally related urinary substances. Very good correlation was observed between urinary serotonin levels measured by ELISA and liquid chromatography tandem mass spectrometry (LC-MS/MS; ELISA = 1.16 × LC-MS/MS - 53.8; r = 0.965; mean % bias = 11%; n = 18). Serotonin was stable in acidified urine for 30 days at room temperature and at -20 °C. The established reference range for serotonin was 54-366 µg/g Cr (n = 64). Serotonin levels detected in depressed patients (87.53 ± 4.89 µg/g Cr; n = 60) were significantly lower (p < 0.001) than in nondepressed subjects (153.38 ± 7.99 µg/g Cr). Urinary excretion of serotonin in depressed individuals significantly increased after antidepressant treatment by 5-hydroxy-tryptophane and/or selective serotonin re-uptake inhibitor (p < 0.01). The present ELISA provides a convenient and robust method for monitoring urinary serotonin. It is suitable to monitor serotonin imbalances and may be particularly helpful in evaluating antidepressant therapies.

Urinary excretion of 5-hydroxy-3-indoleacetic acid in dystimic/depressed, adult obese women: what correlations to hepatic steatosis?

The synthesis of serotonin at CNS level is influenced by diet. Moreover, insulin resistance is associated with lower serotonin levels. Visceral obesity, strictly linked to hepatic steatosis is specifically associated with mild to severe somatic affective-depressive symptom clusters. Previous data support the view that depression involves serotonergic systems, reflecting low levels of urinary 5- hydroxy-3-indoleacetic acid (5-HIAA). The 24-h urinary excretion of 5-HIAA was evaluated in 76 dystimic/depressed, obese/overweight females, divided into two groups, i.e., on a hyper-caloric diet, associated with a life style characterized by leisure time sedentary behavior (LTSB, 35 women), or on a normo-caloric diet, assisted by program-based strategies aimed at promoting physical activity participation (PAP, 41 women). Beck Depression Inventory (BDI) was carried out to score the severity of dystimia/depression. Anthropometric measures, metabolic indices, severity of hepatic steatosis at sonography and HOMA were studied. Urinary levels of 5-HIAA in controls and PAP groups were comparable with a great overlap, while in the LTSB group the urinary excretion of 5-HIAA was significantly reduced in respect to that of the PAP group and obviously compared to that of the control group, 3.4±1.4 mg/L versus 6.2±2.7 mg/L and 6.4±2.6 mg/L, respectively, ANOVA test, P= 0.001. Among metabolic indices, cholesterol, HDL-cholesterol, triglycerides and uric acid were not able to predict urinary concentrations of 5-HIAA, which were not associated with hepatic steatosis; vice versa, ferritin levels, and mainly HOMA values, were independent predictors of the urinary excretion of 5-HIAA (ß=0.235 and 0.45, respectively). Dystimia/depression severity was negatively predicted by urinary 5-HIAA levels in the sense that the highest BDI values were forecast by the lowest values of urinary 5-HIAA (ß= -0.72).The importance of measuring the 24-h urinary excretion of 5-HIAA in follow-ups could rely on a method simultaneously mirroring the well-being status, the adherence to physical activity, which leads to improved insulin sensitivity, and the eating habits acquired by dystimic/depressed overweight/obese patients. In contrast, the significance of the urinary 5-HIAA is reduced in evaluating the severity of hepatic steatosis, likely because it is a structured process.

6­Sulfatoxymelatonin as a predictor of clinical outcome in depressive patients.

OBJECTIVES: This study established the value of the 6­sulfatoxymelatonin (aMT6s) urine concentration as a predictor of the therapeutic response to noradrenaline reuptake inhibitors in depressive patients. METHODS: Twenty-two women aged 18-60 years were selected. Depressive symptoms were assessed by using the Hamilton Depression Scale. Urine samples were collected at 0600-1200 h, 1200-1800 h, 1800-2400 h, and 2400-0600 h intervals, 1 day before and 1 day after starting on the nortriptyline treatment. Urine aMT6s concentration was analyzed by a one-way analysis of variance/Bonferroni test. Spearman's rank correlation coefficient was used to analyze the correlation between depressive symptoms after 2 weeks of antidepressant treatment and the increase in aMT6s urine concentration. RESULTS: Higher and lower size effect groups were compared by independent Student's t-tests. At baseline, the 2400­ to 0600­h interval differed from all other intervals presenting a significantly higher aMT6s urine concentration. A significant difference in aMT6s urine concentrations was found 1 day after treatment in all four intervals. Higher size effect group had lower levels of depressive symptoms 2 weeks after the treatment. A positive correlation between depressive symptoms and the delta of aMT6s in the 2400-0600 h interval was observed. CONCLUSION: Our results reinforce the hypothesis that aMT6s excretion is a predictor of clinical outcome in depression, especially in regard to noradrenaline reuptake inhibitors.

Sleep symptoms during the menopausal transition and early postmenopause: observations from the Seattle Midlife Women's Health Study.

STUDY OBJECTIVES: Describe the severity of getting to sleep, nighttime awakening, and early morning awakening across the menopausal transition (MT) and early postmenopause (PM) and their relationship to age, menopausal transition factors, symptoms, stress-related factors, and health related factors. DESIGN: Cohort. SETTING: community. PARTICIPANTS: 286 women from the Seattle Midlife Women's Health Study cohort. MEASUREMENTS: Participants completed annual menstrual calendars for MT staging, diaries in which they rated their symptoms, stress levels, and perceived health multiple times per year from 1990-2007 and provided first morning urine samples assayed for E1G, FSH, cortisol, and catecholamines. Multilevel modeling (R program) was used for data analysis. RESULTS: Severity of self-reported problems going to sleep was associated with all symptoms, perceived stress, history of sexual abuse, perceived health (-), alcohol use (-) (all P < 0.001), and lower cortisol (P = 0.009), but not E1G or FSH. Severity of nighttime awakening was significantly associated with age, late MT stage, and early PM, FSH, E1G (-), hot flashes, depressed mood, anxiety, joint pain, backache, perceived stress, history of sexual abuse, perceived health (-), and alcohol use (-) (all P < 0.001, except E1G for which P = 0.030). Severity of early morning awakening was significantly associated with age, hot flashes, depressed mood anxiety, joint pain, backache, perceived stress, history of sexual abuse, perceived health (-) (all P < or = 0.001, except E1G for which P = 0.02 and epinephrine (P = 0.038), but not MT stages or FSH. Multivariate models for each symptom included hot flashes, depressed mood, and perceived health. CONCLUSION: Sleep symptoms during the MT may be amenable to symptom management strategies that take into account the symptom clusters and promote women's general health rather than focusing only on the MT.

Urinary 6-sulphatoxymelatonin levels are depressed in chronic migraine and several comorbidities.

OBJECTIVE: To assess urinary 6-sulphatoxymelatonin levels in a large consecutive series of patients with migraine and several comorbidities (chronic fatigue, fibromyalgia, insomnia, anxiety, and depression) as compared with controls. BACKGROUND: Urine analysis is widely used as a measure of melatonin secretion, as it is correlated with the nocturnal profile of plasma melatonin secretion. Melatonin has critical functions in human physiology and substantial evidence points to its importance in the regulation of circadian rhythms, sleep, and headache disorders. METHODS: Urine samples were collected into a single plastic container over a 12-hour period from 8:00 pm to 8:00 am of the next day, and 6-sulphatoxymelatonin was measured by quantitative ELISA. All of the patients were given a detailed questionnaire about headaches and additionally answered the following questionnaires: Chalder fatigue questionnaire, Epworth somnolence questionnaire, State-Trait Anxiety Inventory, and the Beck Depression Inventory. RESULTS: A total of 220 subjects were evaluated - 73 (33%) had episodic migraine, 73 (33%) had chronic migraine, and 74 (34%) were enrolled as control subjects. There was a strong correlation between the concentration of 6-sulphatoxymelatonin detected and chronic migraine. Regarding the comorbidities, this study objectively demonstrates an inverse relationship between 6-sulphatoxymelatonin levels and depression, anxiety, and fatigue. CONCLUSIONS: To our knowledge, this is the first study to evaluate the relationship between the urinary concentration of melatonin and migraine comorbidities. These results support hypothalamic involvement in migraine pathophysiology.

Does night-time cortisol excretion normalize in the long-term course of depression?

INTRODUCTION: While there is extensive literature on HPA system activity in acutely depressed patients, there is only limited information about the presence of hypercortisolemia during the interepisode interval of affective disorders. We hypothesized an increase in HPA system activity in depressed patients compared to controls, and proposed that night-time cortisol excretion during follow-up will depend on clinical outcome. METHODS: We measured night-time cortisol excretion in 27 patients during an acute episode of major depression as well as a 20-week follow-up. 40 healthy subjects served as control group. RESULTS: During the acute episode depressed patients showed increased levels of night-time cortisol excretion compared to healthy controls. Both, patients with full and sustained remission (n=8) as well as patients with incomplete remission or relapse (n=19) showed declining cortisol excretion in night-time urine during follow-up. At the end of follow-up cortisol excretion did not differ between patients with affective disorder and healthy controls. DISCUSSION: Irrespective of residual depressive symptoms, HPA system activity declines after the generally investigated acute depressive episode.

Urinary catecholamine levels and response to group cognitive behaviour therapy in depression.

AIM: The aim was to investigate whether high catecholamine (CA) excreters would respond less well to a group cognitive behaviour therapy (CBT) treatment for depression than others. METHOD: A sample of 70 adults with depression symptoms participated in a 12-week course of group CBT. Participants' 24 hour urinary catecholamine levels at pre-therapy and post-therapy were used to classify them as High (N = 10); Low (N = 33) or Mixed (N = 27) according to a cut-off one standard deviation above a published mean for healthy adults. Beck Depression Inventory (BDI) and cognitions questionnaire (Automatic Thoughts Questionnaire; Beck Hopelessness Scale and Dysfunctional Attitudes Scale) were used. RESULTS: Repeated measures ANOVA analyses showed an equal rate of mood improvement in all three groups over the course of CBT, despite the fact that the High excreters were on average more depressed throughout the study. Changes in depression symptoms were mirrored by improvements in cognitive measures in the three catecholamine groups. CONCLUSION: This study indicates that adults showing a biological marker of depression (elevated catecholamine levels) are equally able to benefit from CBT treatment as adults without this marker.

Urothelial toxicity of esketamine in the treatment of depression.

RATIONALE: Ketamine is the first widely used substance with rapid-onset antidepressant action. However, there are uncertainties regarding its potential urothelial toxicity, particularly after repeated application. In the context of rising recreational ketamine use, severe side effects affecting the human urinary tract have been reported. It is assumed that ketamine interacts with bladder urothelial cells and induces apoptosis. OBJECTIVES: This study aimed to assess whether single or repeated doses of esketamine used in an antidepressant indication are associated with urinary toxicity. METHODS: We included male and female inpatients with a current episode of depression and a diagnosis of recurrent depressive disorder, bipolar disorder or schizoaffective disorder according to ICD-10 criteria (n = 25). The esketamine treatment schedule involved a maximum of 3× weekly dosing at 0.25-0.5 mg/kg i.v. or s.c. The primary outcome was the change in urine toxicity markers (leukocytes, erythrocytes, protein and free haemoglobin). Description of demographic, clinical and laboratory data was conducted using means, standard deviations, frequencies and percentages. Changes in urinary toxicity markers over time were evaluated using linear mixed models with gender as a covariate. RESULTS: The participants received an average of 11.4 (SD 8) esketamine treatments, and an average number of 11.2 (SD 8) urine samples were analysed over the course of treatment. Neither urinary leukocyte concentration (F(20; 3.0) = 3.1; p = 0.2) nor erythrocyte concentration (F(20;2.2) = 4.1; p = 0.2) showed a significant trend towards increase during the course of esketamine treatment. Similarly, free haemoglobin and protein concentrations, which were analysed descriptively, did not display a rise during treatment. There was a significant improvement in depression ratings after esketamine treatment (p < 0.001). CONCLUSIONS: This study is, to the best of our knowledge, the first to focus on urothelial toxicity of esketamine used in antidepressant indication and dose. The results indicate that the use of single or repeated doses of esketamine is unlikely to cause urothelial toxicity. The results are in need of confirmation as sample size was small.

Urinary phenyl acetate: a diagnostic test for depression?

The compound 2-phenylethylamine is an "endogenous amphetamine" which may modulate central adrenergic functions. 2-Phenylethylamine is mainly metabolized by monoamine oxidase to form phenyl acetate (PAA). The 24-hour urinary excretion of PAA was measured in normal healthy volunteers and depressed patients. Patients were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, edition 3. In 70 percent of healthy volunteers of both sexes, the excretion of PAA ranged between 70 and 175 milligrams per 24 hours (mean = 141.1 +/- 10.2). Inpatients with major depressive disorder (unipolar type) (N = 31) excreted less PAA (68.7 +/- 7.0 milligrams per 24 hours) and 55 percent of them excreted less than 70 milligrams per 24 hours; there were no significant differences in the PAA excretion between untreated patients (N = 13) and those treated with antidepressants that were not effective (N = 18). The PAA excretion was reduced to a lesser extent in 35 less severely depressed unipolar outpatients (drug-free for 1 week) (86.3 +/- 11.8 milligrams per 24 hours). These results suggest that low PAA urinary excretion may be a reliable state marker for the diagnosis of some forms of unipolar major depressive disorders.

Enhanced norepinephrine output during long-term desipramine treatment: a possible role for the extraneuronal monoamine transporter (SLC22A3).

To study the delay (2-6 weeks) between initial administration of norepinephrine reuptake inhibitor antidepressants and onset of clinical antidepressant action, we examined the effects of desipramine treatment on urinary and plasma catecholamines and their metabolites during the initial 6 weeks of treatment in depressed patients. Catecholamines and metabolites in 24-h urine collections and 8:00 a.m. plasma samples were measured at baseline and after 1, 4, and 6 weeks of desipramine treatment. Desipramine treatment produced significant increases in urinary norepinephrine (NE) and normetanephrine (NMN) and plasma NE at Weeks 4 and 6, but not at Week 1. The ratio of urinary NE/NMN was increased at Weeks 4 and 6, suggesting a reduction in the metabolism of NE to NMN at extraneuronal sites by Weeks 4 and 6. The increases in urinary NE and NMN and plasma NE at Weeks 4 and 6 of desipramine treatment were associated with a reduction in the conversion of NE to NMN. This would be compatible with a blockade of the extraneuronal monoamine transporter (organic cation transporter 3; SLC22A3) by NMN. Inhibition of the extraneuronal monoamine transporter may be an important component in the clinical pharmacology of the norepinephrine reuptake inhibitor antidepressant drugs, such as desipramine.

Urinary biomarker panel for diagnosing patients with depression and anxiety disorders.

Available data indicate that patients with depression and anxiety disorders are likely to be at greater risk for suicide. Therefore, it is important to correctly diagnose patients with depression and anxiety disorders. However, there are still no empirical laboratory methods to objectively diagnose these patients. In this study, the multiple metabolomics platforms were used to profile the urine samples from 32 healthy controls and 32 patients with depression and anxiety disorders for identifying differential metabolites and potential biomarkers. Then, 16 healthy controls and 16 patients with depression and anxiety disorders were used to independently validate the diagnostic performance of the identified biomarkers. Finally, a panel consisting of four biomarkers-N-methylnicotinamide, aminomalonic acid, azelaic acid and hippuric acid-was identified. This panel was capable of distinguishing patients with depression and anxiety disorders from healthy controls with an area under the receiver operating characteristic curve of 0.977 in the training set and 0.934 in the testing set. Meanwhile, we found that these identified differential metabolites were mainly involved in three metabolic pathways and five molecular and cellular functions. Our results could lay the groundwork for future developing a urine-based diagnostic method for patients with depression and anxiety disorders.

Overnight urinary cortisol release in women with borderline personality disorder depends on comorbid PTSD and depressive psychopathology.

Free cortisol was investigated in BPD patients and healthy controls. A positive association was found between cortisol and depression scores, while the number of PTSD symptoms was negatively correlated with cortisol release. These findings suggest that alterations in cortisol release in BPD are strongly associated with the severity of psychopathology.

Lower rates of consistent urine drug tests for prescribed psychotropic medications among patients on opioid replacement therapy.

BACKGROUND: Patients on opioid replacement therapy (ORT) to treat opioid use disorder are frequently monitored for these medications, but it is not known if they are also adhering to their psychotropic medications. This is an analysis of measure of potential adherence to psychotropic medications by patients on ORT. METHODS: This is a retrospective cohort study of patients (n=1470) on antidepressants and/or antipsychotics and tested by the Millennium Health laboratory. Potential adherence to psychotropic medications was measured by urine drug test (UDT) results. The consistency of UDT for expected psychotropic medication in patients on ORT was compared to patients not on ORT (control group) during 3-months period. The study used propensity score methods to match individuals from both groups on their demographics and their psychotropic medication. RESULTS: There were 457 participants (31.09%) on ORT and 1013 participants (68.91%) in the control group. Only 55.33% of UDTs (n=1388) were consistent for expected psychotropic medications in the ORT group compared to 73.69% of UDTs (n=4953) consistent for expected psychotropic medications in the control group (χ2=172.99, p<0.001). After matching, patients in the ORT group were less likely than the control group to have consistent UDTs for expected psychotropic medications (OR: 0.81, 95% CI: 0.76-0.85, P<0.001). CONCLUSION: There is a high rate of inconsistent UDT for prescribed psychotropic medication among patients on ORT. This could reflect potential poor adherence. Monitoring adherence to psychotropic medications should be part of every clinical visit for patients on ORT.

Depressive symptoms and 24-hour urinary norepinephrine excretion levels in patients with coronary disease: findings from the Heart and Soul Study.

OBJECTIVE: Depressive symptoms are associated with an increased risk of cardiac events in patients with heart disease. Elevated catecholamine levels may contribute to this association, but whether depressive symptoms are associated with catecholamine levels in patients with heart disease is unknown. METHOD: The authors examined the association between depressive symptoms (defined by a Patient Health Questionnaire score > or =10) and 24-hour urinary norepinephrine, epinephrine, and dopamine excretion levels in 598 subjects with coronary disease. RESULTS: A total of 106 participants (18%) had depressive symptoms. Participants with depressive symptoms had greater mean norepinephrine excretion levels than those without depressive symptoms (65 microg/day versus 59 mug/day, with adjustment for age, sex, body mass index, smoking, urinary creatinine levels, comorbid illnesses, medication use, and cardiac function). In logistic regression analyses, participants with depressive symptoms were more likely than those without depressive symptoms to have norepinephrine excretion levels in the highest quartile and above the normal range. Depressive symptoms were not associated with dopamine or epinephrine excretion levels. CONCLUSIONS: In patients with coronary disease, depressive symptoms are associated with elevated norepinephrine excretion levels. Future longitudinal studies are needed to determine whether elevations in norepinephrine contribute to adverse cardiac outcomes in patients with depressive symptoms.

Initial urinary epinephrine and cortisol levels predict acute PTSD symptoms in child trauma victims.

BACKGROUND: Previous research examining biological correlates of posttraumatic stress disorder (PTSD) in children has suggested that children with chronic PTSD have altered levels of catecholamines and cortisol compared to similarly traumatized children who do not meet diagnostic criteria. The present study extended these findings by examining whether urinary hormone levels collected soon after a trauma were related to subsequent acute PTSD symptoms in child trauma victims. METHODS: Initial 12-h urine samples were collected from 82 children aged 8-18 admitted to a Level 1 trauma center. Collection was begun immediately upon admission, and samples were assayed for levels of catecholamines and cortisol. PTSD and depressive symptomatology were assessed 6 weeks following the accident. RESULTS: Initial urinary cortisol levels were significantly correlated with subsequent acute PTSD symptoms (r=0.31). After removing the variance associated with demographic variables and depressive symptoms, urinary cortisol and epinephrine levels continued to predict a significant percentage (7-10%) of the variance in 6-week PTSD symptoms. Examination of boys and girls separately suggested that significance was primarily driven by the strength of the relationships between hormone levels and acute PTSD symptoms in boys. CONCLUSIONS: The present findings suggest that high initial urinary cortisol and epinephrine levels immediately following a traumatic event may be associated with increased risk for the development of subsequent acute PTSD symptoms, especially in boys.

Subtypes of depression based on excretion of MHPG and response to nortriptyline.

We investigated the relationship between urinary excretion of MHPG and the clinical response of 17 depressed patients to nortriptyline hydrochloride. Plasma concentrations of nortriptyline were monitored to assure optimal doses. Patients were classified as having "low" or "normal-high" excretion of MHPG based on one to five 24-hour urine specimens. Hamilton Depression Rating Scale scores were not reduced significantly more among the nine low excreters as compared with the eight normal-high excreters. However, when a true bimodal distribution of MHPG excretion was created by comparing only the six lowest excreters with the six highest excreters, the low group improved significantly more than the high group. This differential response to nortriptyline somewhat supports the notion that MHPG excretion may predict response to specific tricyclics. Collecting urine for MHPG determination in depressed patients is not easy; the variability of excretion within patients is considerable, and the range of MHPG excretion closely parallels that in normal persons. The clinical utility of this procedure is still to be determined.

High correlation of norepinephrine and its major metabolite excretion rates.

Twenty-four-hour urinary excretion rates of norepinephrine, normetanephrine, 3-methoxy-4-hydroxyphenylglycol, and (vanillylmandelic) acid were repeatedly measured in 12 depressed patients. High (greater than. 83) positive correlations were found between the excretion rates of these four substances. Based on these findings, the conclusion was reached that in depressed patients the 24-hour urinary excretion rates of norepinephrine and any of its three major metabolites reflect total norepinephrine production in the body.

High intercorrelations among urinary outputs of norepinephrine and its major metabolites. A replication in depressed patients and controls.

We examined the intercorrelations among urinary outputs of norepinephrine (NE) and its three major metabolites in unipolar depressed patients (n = 28) and normal controls (n = 24). Among the depressed patients, levels of NE correlated with normetanephrine (NM), 3-methoxy-4-hydroxyphenylglycol (MHPG), and vanillylmandelic acid (VMA), and VMA correlated with NM and MHPG. In the total group of depressed and control subjects (n = 52), the sum of NE and its major metabolites correlated with urinary outputs of NE, NM, MHPG, and VMA. These highly significant correlations among urinary outputs of NE and its major metabolites replicate a previous report of strong correlations among these same four urinary substances in a smaller group of depressed patients.

Neuroendocrine aspects of primary endogenous depression. I. Cortisol secretory dynamics in patients and matched controls.

To examine both predexamethasone and postdexamethasone cortisol measures in depression, we determined circadian serum cortisol patterns, cortisol responses to dexamethasone, and 24-hour urinary free cortisol excretion before and after dexamethasone administration in 40 patients with primary, definite endogenous depression diagnosed by Research Diagnostic Criteria and in 40 individually matched normal control subjects. Fifteen patients (38%) were dexamethasone nonsuppressors; they had significantly higher predexamethasone serum and urine cortisol measures than both their matched controls and the 25 suppressor patients. Both the predexamethasone and postdexamethasone cortisol measures were unimodally distributed across the patients and the controls. Circadian cortisol rhythms of similar magnitude occurred in both groups. The cortisol measures before and after dexamethasone administration were positively correlated to a similar degree in the patients and their controls, suggesting that predexamethasone hypothalamic-pituitary-adrenocortical hyperactivity and postdexamethasone cortisol nonsuppression are not independently determined in endogenous depression.

Marked reduction in indexes of dopamine metabolism among patients with depression who attempt suicide.

Cerebrospinal fluid studies have reported that low concentrations of the dopamine metabolite homovanillic acid are associated with suicidal behavior in depression. Although only a small proportion of homovanillic acid in the urine derives from the brain, we decided to examine 24-hour urinary outputs of homovanillic acid in relation to suicidal behavior in depression. Patients with depression who had attempted suicide had significantly smaller urinary outputs of homovanillic acid, dihydroxyphenylacetic acid, and total body output of dopamine (sum dopamine) than did patients with depression who had not attempted suicide. Patients with depression who reattempted suicide during 5-year follow-up had significantly smaller urinary outputs of homovanillic acid and sum dopamine than did patients who did not reattempt suicide, patients who never attempted suicide, and normal control subjects, and had significantly smaller outputs of dihydroxyphenylacetic acid than patients who never attempted suicide or control subjects. These data suggest that urinary outputs of homovanillic acid may be peripheral correlates of suicidality in depression. These data add to data on the low levels of homovanillic acid in cerebrospinal fluid in suggesting that diminished dopaminergic neurotransmission may play a part in suicidal behavior in depression.