Serotonin transporter 5HTTLPR polymorphism and affective disorders: no evidence of association in a large European multicenter study

The available data from preclinical and pharmacological studies on the role of the serotonin transporter (5-HTT) support the hypothesis that a dysfunction in brain serotonergic system activity contributes to the vulnerability to affective disorders (AD). 5-HTT is the major site of serotonin reuptake into the presynaptic neuron, and it has been shown that the polymorphic repeat polymorphism in the 5-HTT promotor region (5-HTTLPR) may affect gene-transcription activity. 5-HTT maps to chromosome 17 at position 17q11.17-q12, and the 5-HTTLPR polymorphisms have been extensively investigated in AD with conflicting results. The present study tested the genetic contribution of the 5-HTTLPR polymorphism in a large European multicenter case-control sample, including 539 unipolar (UPAD), 572 bipolar patients (BPAD), and 821 controls (C). Our European collaboration has led to efforts to optimize a methodology that attenuates some of the major limitations of the case-control association approach. No association was found with primary psychiatric diagnosis (UPAD and BPAD) and with phenotypic traits (family history of AD, suicidal attempt, and presence of psychotic features). Our negative findings are not attributable to the lack of statistical power, and may contribute to clarify the role of 5-HTTLPR polymorphism in AD.

Clinical characteristics and treatment outcomes of patients with major depressive disorder and comorbid anxiety disorders - results from a European multicenter study

This naturalistic European multicenter study aimed to elucidate the association between major depressive disorder (MDD) and comorbid anxiety disorders. Demographic and clinical information of 1346 MDD patients were compared between those with and without concurrent anxiety disorders. The association between explanatory variables and the presence of comorbid anxiety disorders was examined using binary logistic regression analyses. 286 (21.2%) of the participants exhibited comorbid anxiety disorders, 10.8% generalized anxiety disorder (GAD), 8.3% panic disorder, 8.1% agoraphobia, and 3.3% social phobia. MDD patients with comorbid anxiety disorders were characterized by younger age (social phobia), outpatient status (agoraphobia), suicide risk (any anxiety disorder, panic disorder, agoraphobia, social phobia), higher depressive symptom severity (GAD), polypsychopharmacy (panic disorder, agoraphobia), and a higher proportion receiving augmentation treatment with benzodiazepines (any anxiety disorder, GAD, panic disorder, agoraphobia, social phobia) and pregabalin (any anxiety disorder, GAD, panic disorder). The results in terms of treatment response were conflicting (better response for panic disorder and poorer for GAD). The logistic regression analyses revealed younger age (any anxiety disorder, social phobia), outpatient status (agoraphobia), suicide risk (agoraphobia), severe depressive symptoms (any anxiety disorder, GAD, social phobia), poorer treatment response (GAD), and increased administration of benzodiazepines (any anxiety disorder, agoraphobia, social phobia) and pregabalin (any anxiety disorder, GAD, panic disorder) to be associated with comorbid anxiety disorders. Our findings suggest that the various anxiety disorders subtypes display divergent clinical characteristics and are associated with different variables. Especially comorbid GAD appears to be characterized by high symptom severity and poor treatment response.

Cerebrospinal fluid neurophysins in affective illness and in schizophrenia

We studied the concentration of neurophysin I (hNPI) and II (hNPII), the hypothalamo-pituitary carriers of vasopressin and oxytocin, in CSF of depressed and schizophrenic patients and age matched controls. Mean hNPI values were lower and mean hNPII values greater in schizophrenics than in controls. Lower hNPI values were observed in unipolar patients than in controls. In bipolar patients however, higher hNPI values were present. Significantly higher hNPII values were observed in bipolar patients than in controls; no difference was present between unipolars and controls. A positive correlation was observed with age in controls and bipolars for hNPII. These data emphasize the interest of studying the neurohypophysal function in affective illness and in schizophrenia.

Multicompartmental study of fluorine-18 altanserin binding to brain 5HT2 receptors in humans using positron emission tomography

Serotoninergic type 2 (5HT2) receptors have been implicated in the regulation of many brain functions in humans and may play a role in several neurological and psychiatric diseases. Fluorine-18 altanserin has been proposed as a new radiotracer for the study of 5HT2 receptors by PET because of its high affinity for 5HT2 receptors (Ki: 0.13 nM) and its good specificity in in vitro studies. Dynamic PET studies were carried out in 12 healthy volunteers after intravenous injection of 0.1 mCi/kg [18F]altanserin. Ninety minutes after injection, we observed mainly cortical binding. Basal ganglia and cerebellum showed very low uptake and the frontal cortex to cerebellum ratio was about 3. To evaluate the quantitative distribution of this ligand in the brain, we used two different methods of data analysis: a four-compartment model was used to achieve quantitative evaluation of rate constants (K1 and k2 through k6) by non-linear regression, and a multiple-time graphical analysis technique for reversible binding was employed for the measurement of k1/k2 and k3/k4 ratios. Using both methods, we found significant differences in binding capacity (estimated by k3/k4 = Bmax/Kd) between regions, the values increasing as follows: occipital, limbic, parietal, frontal and temporal cortex. After correction of values obtained by the graphical method for the existence of non-specific binding, results generated by the two methods were consistent.

Consensus paper of the WFSBP Task Force on Genetics: Genetics, epigenetics and gene expression markers of major depressive disorder and antidepressant response

Major depressive disorder (MDD) is a heritable disease with a heavy personal and socio-economic burden. Antidepressants of different classes are prescribed to treat MDD, but reliable and reproducible markers of efficacy are not available for clinical use. Further complicating treatment, the diagnosis of MDD is not guided by objective criteria, resulting in the risk of under- or overtreatment. A number of markers of MDD and antidepressant response have been investigated at the genetic, epigenetic, gene expression and protein levels. Polymorphisms in genes involved in antidepressant metabolism (cytochrome P450 isoenzymes), antidepressant transport (ABCB1), glucocorticoid signalling (FKBP5) and serotonin neurotransmission (SLC6A4 and HTR2A) were among those included in the first pharmacogenetic assays that have been tested for clinical applicability. The results of these investigations were encouraging when examining patient-outcome improvement. Furthermore, a nine-serum biomarker panel (including BDNF, cortisol and soluble TNF-α receptor type II) showed good sensitivity and specificity in differentiating between MDD and healthy controls. These first diagnostic and response-predictive tests for MDD provided a source of optimism for future clinical applications. However, such findings should be considered very carefully because their benefit/cost ratio and clinical indications were not clearly demonstrated. Future tests may include combinations of different types of biomarkers and be specific for MDD subtypes or pathological dimensions.

Social adjustment and self-esteem of bipolar patients: a multicentric study

The aim of the present study was to investigate impairment in social adjustment and self-esteem of bipolar patients (n=144) in remission for at least 3 months. Patients were recruited among four different centres: Sofia, Athens, Jerusalem and Milan, and were individually matched to control subjects in relation to sex, age and geographical origin. Subjects completed the Rosenberg self-esteem scale (SES) and the self-report version of the social adjustment scale (SAS). Bipolar patients reported to experience more difficulties in social adjustment than controls, specifically for leisure and work activities. Further, our results show that bipolar patients have significantly lower self-esteem compared to controls, even after remission.

A New Prediction Model for Evaluating Treatment-Resistant Depression

OBJECTIVE

Despite a broad arsenal of antidepressants, about a third of patients suffering from major depressive disorder (MDD) do not respond sufficiently to adequate treatment. Using the data pool of the Group for the Study of Resistant Depression and machine learning, we intended to draw new insights featuring 48 clinical, sociodemographic, and psychosocial predictors for treatment outcome.

METHOD

Patients were enrolled starting from January 2000 and diagnosed according to DSM-IV. Treatment-resistant depression (TRD) was defined by a 17-item Hamilton Depression Rating Scale (HDRS) score ≥ 17 after at least 2 antidepressant trials of adequate dosage and length. Remission was defined by an HDRS score < 8. Stepwise predictor reduction using randomForest was performed to find the optimal number for classification of treatment outcome. After importance values were generated, prediction for remission and resistance was performed in a training sample of 400 patients. For prediction, we used a set of 80 patients not featured in the training sample and computed receiver operating characteristics.

RESULTS

The most useful predictors for treatment outcome were the timespan between first and last depressive episode, age at first antidepressant treatment, response to first antidepressant treatment, severity, suicidality, melancholia, number of lifetime depressive episodes, patients' admittance type, education, occupation, and comorbid diabetes, panic, and thyroid disorder. While single predictors could not reach a prediction accuracy much different from random guessing, by combining all predictors, we could detect resistance with an accuracy of 0.737 and remission with an accuracy of 0.850. Consequently, 65.5% of predictions for TRD and 77.7% for remission can be expected to be accurate.

CONCLUSIONS

Using machine learning algorithms, we could demonstrate success rates of 0.737 for predicting TRD and 0.850 for predicting remission, surpassing predictive capabilities of clinicians. Our results strengthen data mining and suggest the benefit of focus on interaction-based statistics. Considering that all predictors can easily be obtained in a clinical setting, we hope that our model can be tested by other research groups.

Association study of bipolar disorder with candidate genes involved in catecholamine neurotransmission: DRD2, DRD3, DAT1, and TH genes

Despite strong evidence for genetic involvement in the etiology of affective disorders (from twin adoption and family studies), linkage and association methodologies are still exploring the nature of genetic factors in these diseases. Interesting testable hypotheses have been described, including candidate genes involved in catecholamine neurotransmission. We studied 69 bipolar patients and 69 matched controls (for age, sex, and geographical origin) for association and linkage disequilibrium with DNA markers at the following genes: the tyrosine hydroxylase gene, dopamine transporter gene, and dopamine D2 and D3 receptor genes. Association and linkage disequilibrium were excluded between bipolar affective disorder and these four candidate genes in our sample.

Temperament and Character Inventory (TCI) personality profile and sub-typing in alcoholic patients: a controlled study

Cloninger's Temperament and Character Inventory (TCI) personality profile was used to compare alcohol-dependent patients with non-psychiatric control subjects, and a search made for sub-types of alcoholics with different TCI profiles, using the criteria age of onset of alcohol-related problems, paternal dependence on alcohol and familial antecedents of alcohol dependence. Alcohol-dependent patients (n = 38) were characterized by higher Novelty-Seeking [corresponding to Diagnostic and Statistical Manual of Mental Disorders (4th edition) group B personality type] and lower Self-Directedness than non-psychiatric control subjects (n = 47). Lower Self-Directedness indicates a higher probability of personality disorder in the alcohol-dependent population. Only age of onset of alcohol-related problems delineated the two sub-populations with different TCI profiles: early-onset alcoholics (< or =25 years of age, n = 19), but not late-onset ones (n = 16), in comparison with control subjects, were associated with higher Novelty-Seeking. Both early and late-onset patients scored lower on Self-Directedness than control subjects. Self-Directedness and Cooperation scores were lower in early-onset than in late-onset patients. These results in part support Cloninger's typology, and the TCI data add to evidence concerning a higher probability of personality disorder in alcohol-dependent patients, particularly those with early-onset.

Reduced cholecystokinin immunoreactivity in the cerebrospinal fluid of patients with psychiatric disorders

The close relationship of cholecystokinin peptides with some of the dopamine pathways and the limbic system suggests a putative role for these peptides in the pathophysiology of neuropsychiatric disorders such as Parkinson's disease, manic-depression and schizophrenia. By use of radioimmunoassay, we report a significant decrease in cholecystokinin-immunoreactivity in the cerebrospinal fluid of patients with bipolar manic-depression and untreated schizophrenia in comparison to control subjects.

Socio-demographic and clinical predictors of treatment resistant depression: A prospective European multicenter study

BACKGROUND

Few studies investigated socio-demographic and clinical predictors of non response and remission in treatment resistant depression (TRD) in the case of failure of more than two adequate antidepressant (AD) trial. The primary aim of this study was to investigate socio-demographic and clinical predictors of TRD defined as the lack of response to at least three adequate AD treatments, two of which prospectively evaluated. As secondary aims, we also investigated predictors of non response and remission to: (1) at least two adequate AD treatment (one of which prospectively assessed); (2) at least one adequate and retrospectively assessed AD treatment.

METHODS

In the context of a European multicenter project, 407 major depressive disorder (MDD) patients who failed to respond to a previous AD treatment were recruited for a 2 stage trial, firstly receiving venlafaxine and then escitalopram. MINI, HRSD, MADRS, UKU, CGI-S and CGI-I were administered.

RESULTS

Ninety eight subjects (27.61%) were considered as resistant to three AD treatments. Clinical predictors were: longer duration and higher severity of the current episode (p=0.004; ES=0.24; p=0.01; RR=1.41, respectively), outpatient status (p=0.04; RR=1.58), higher suicidal risk level (p=0.02; RR=1.49), higher rate of the first/second degree psychiatric antecedents (MDD and others) (p=0.04; RR=1.31, p=0.03; RR=1.32 respectively) and side effects during treatments (p=0.002; RR=2.82). Multivariate analyses underlined the association between TRD and the severity of the current episode (p=0.04). As for secondary outcomes, predicting factors were partially overlapping.

LIMITATIONS

The limited sample size and specific drugs used limit present findings.

CONCLUSION

Subjects with a high degree of resistance to AD treatments show specific features which may guide the clinicians to the choice of more appropriate therapies at baseline.

The combined effect of genetic polymorphisms and clinical parameters on treatment outcome in treatment-resistant depression

For over a decade, the European Group for the Study of Resistant Depression (GSRD) has examined single nucleotide polymorphisms (SNP) and clinical parameters in regard to treatment outcome. However, an interaction based model combining these factors has not been established yet. Regarding the low effect of individual SNPs, a model investigating the interactive role of SNPs and clinical variables in treatment-resistant depression (TRD) seems auspicious. Thus 225 patients featured in previous work of the GSRD were enrolled in this investigation. According to data availability and previous positive results, 12 SNPs in HTR2A, COMT, ST8SIA2, PPP3CC and BDNF as well as 8 clinical variables featured in other GSRD studies were chosen for this investigation. Random forests algorithm were used for variable shrinkage and k-means clustering for surfacing variable characteristics determining treatment outcome. Using these machine learning and clustering algorithms, we detected a set of 3 SNPs and a clinical variable that was significantly associated with treatment response. About 62% of patients exhibiting the allelic combination of GG-GG-TT for rs6265, rs7430 and rs6313 of the BDNF, PPP3CC and HTR2A genes, respectively, and without melancholia showed a HAM-D decline under 17 compared to about 34% of the whole study sample. Our random forests prediction model for treatment outcome showed that combining clinical and genetic variables gradually increased the prediction performance recognizing correctly 25% of responders using all 4 factors. Thus, we could confirm our previous findings and furthermore show the strength of an interaction-based model combining statistical algorithms in identifying and operating treatment predictors.

EEG sleep patterns in man: a twin study

All-night EEG sleep recording was performed for 3 consecutive nights in 26 pairs of normal male twins (14 monozygotic and 12 dizygotic) in order to investigate genetic components of sleep. The analysis was based on average values of repeated sleep measures and controlled for the effect of cohabitation. Our results indicate that a significant proportion of variance in stages 2, 4 and delta sleep as well as in REM density is genetically determined in man. Genetic influences on stage 1 and REM are strongly confounded by a synchronizing effect of the cohabitational status.

Simultaneous study of 24-hour patterns of melatonin and cortisol secretion in depressed patients

The temporal organization of melatonin and cortisol secretion were studied in depressed patients in order to investigate a possible relationship between the secretory patterns of the two hormones. Women who suffered from a primary affective disorder were studied twice as inpatients, the first time during the depressive episode and the second time after amitriptyline treatment and clinical recovery. During both 24-hour studies blood was collected at 1-hour intervals during the day and at 30-min intervals at night. A dissociation of melatonin and cortisol secretory patterns was observed in the 3 patients in whom the two hormones were determined simultaneously. 2 patients exhibited alterations in the circadian rhythm of both hormones during illness. After recovery, however, the melatonin rhythm remained altered but the cortisol rhythm was normalized. Another patient showed a nocturnal melatonin rise and day-night melatonin differences closer to those seen in normal subjects, but she had altered cortisol secretory patterns during depression which normalized after recovery. These results suggest that the melatonin and cortisol rhythms are controlled by different mechanisms.

Non-replication of the brain-derived neurotrophic factor (BDNF) association in bipolar affective disorder: a Belgian patient-control study

This patient-control association study was conducted to investigate a possible association of two single nucleotide polymorphisms (SNPs), g.11757C > G and g.196G > A, in the brain-derived neurotrophic factor (BDNF) with bipolar affective disorder (BPAD). Two hundred seventy-five individuals of Belgian origin (at least two generations of Belgian ancestors) were genotyped (112 BPAD and 163 controls). No significant differences were found in the frequency of genotypes and alleles of g.196G > A (P = 0.37 and 0.94, respectively) and g.11757C > G (P = 0.49 and 0.59, respectively) between controls and BPAD patients. An haplotype analysis revealed no difference between patients and controls (P = 0.44). We failed to replicate previous findings implicating BDNF in the aetiology of BPAD. However, BDNF remains an interesting target for future genetic studies and should be tested in prospective pharmacogenetic therapeutic trials.

CYP2C19 genotype predicts steady state escitalopram concentration in GENDEP

In vitro work shows CYP2C19 and CYP2D6 contribute to the metabolism of escitalopram to its primary metabolite, N-desmethylescitalopram. We report the effect of CYP2C19 and CYP2D6 genotypes on steady state morning concentrations of escitalopram and N-desmethylescitalopram and the ratio of this metabolite to the parent drug in 196 adult patients with depression in GENDEP, a clinical pharmacogenomic trial. Subjects who had one CYP2D6 allele associated with intermediate metabolizer phenotype and one associated with poor metabolizer (i.e. IM/PM genotypic category) had a higher mean logarithm escitalopram concentration than CYP2D6 extensive metabolizers (EMs) (p = 0.004). Older age was also associated with higher concentrations of escitalopram. Covarying for CYP2D6 and age, we found those homozygous for the CYP2C19*17 allele associated with ultrarapid metabolizer (UM) phenotype had a significantly lower mean escitalopram concentration (2-fold, p = 0.0001) and a higher mean metabolic ratio (p = 0.0003) than EMs, while those homozygous for alleles conferring the PM phenotype had a higher mean escitalopram concentration than EMs (1.55-fold, p = 0.008). There was a significant overall association between CYP2C19 genotypic category and escitalopram concentration (p = 0.0003; p = 0.0012 Bonferroni corrected). In conclusion, we have demonstrated an association between CYP2C19 genotype, including the CYP2C19*17 allele, and steady state escitalopram concentration.

Tryptophan hydroxylase polymorphism and suicidality in unipolar and bipolar affective disorders: a multicenter association study

BACKGROUND

Being the rate-limiting enzyme in the biosynthesis of serotonin, the tryptophan hydroxylase gene (TPH) has been considered a possible candidate gene in bipolar and unipolar affective disorders (BPAD and UPAD). Several studies have investigated the possible role of TPH polymorphisms in affective disorders and suicidal behavior.

METHODS

The TPH A218C polymorphism has been investigated in 927 patients (527 BPAD and 400 UPAD) and their matched healthy control subjects collected within the European Collaborative Project on Affective Disorders.

RESULTS

No difference of genotype distribution or allele distribution was found in BPAD or UPAD. No statistically significant difference was observed for allele frequency and genotypes counts. In a genotype per genotype analysis in UPAD patients with a personal history of suicide attempt, the frequency of the C-C genotype (homozygosity for the short allele) was lower in UPAD patients (24%) than in control subjects (43%) (chi(2) = 4.67, p =.03). There was no difference in allele or genotype frequency between patients presenting violent suicidal behavior (n = 48) and their matched control subjects.

CONCLUSIONS

We failed to detect an association between the A218C polymorphism of the TPH gene and BPAD and UPAD in a large European sample. Homozygosity for the short allele is significantly less frequent in a subgroup of UPAD patients with a history of suicide attempt than in control subjects.

Immunoglobulins, autoantibodies and other serum protein fractions in psychiatric disorders

The levels of IgM, IgG and IgA were measured in the serum of 337 psychiatric inpatients (92 patients with bipolar depression, 150 patients with unipolar depression and 95 schizophrenics) and compared to 150 healthy subjects. A significantly higher level of IgM was found in all psychiatric groups compared with the controls, and IgM levels were more elevated in female patients than in male patients for the bipolar and unipolar groups. There were no differences for the other immunoglobulins (IgG, IgA) among the groups studied. In 51 of the patients (17 bipolar, 34 unipolar), other measurements were performed (C-reactive protein, antinuclear antibodies, lymphocyte antibodies, thyroid antibodies, complement and the third and fourth factors of complement). The unipolar group showed a significant rise of C-reactive protein values and the presence of antinuclear antibodies. Interestingly all patients with antinuclear antibodies were females. No difference was found between psychiatric patients and controls in lymphocyte antibodies, thyroid antibodies and values of complement.

Linkage analysis of families with bipolar illness and chromosome 18 markers

Linkage of bipolar (BP) illness with chromosome 18 markers located at 18p11 was recently reported. A possible role for chromosome 18 in the etiology of BP illness was implicated previously by the finding in three unrelated patients of a ring chromosome with breakpoints and deleted segments at 18pter-p11 and 18q23-qter. To test the potential importance of a gene defect on chromosome 18 in our material, we examined linkage with chromosome 18 markers in two families with multiple patients with BP illness or BP spectrum disorders. fourteen simple tandem repeat polymorphisms were used located in the chromosomal region 18p11 to 18q23 and separated by distances of approximately 10 cM on the genetic map. In one family linkage to chromosome 18 could not be excluded. Linkage and segregation analysis in the family suggests that the 12-cM region between D18S51 and D18S61 located at 18q21.33-q23 may contain a candidate gene for BP illness.

Major Depression and the Degree of Suicidality: Results of the European Group for the Study of Resistant Depression (GSRD)

BACKGROUND

This European multicenter study aimed to elucidate suicidality in major depressive disorder. Previous surveys suggest a prevalence of suicidality in major depressive disorder of ≥50%, but little is known about the association of different degrees of suicidality with socio-demographic, psychosocial, and clinical characteristics.

METHODS

We stratified 1410 major depressive disorder patients into 3 categories of suicidality based on the Hamilton Rating Scale for Depression item 3 (suicidality) ratings (0=no suicidality; 1-2=mild/moderate suicidality; 3-4=severe suicidality). Chi-squared tests, analyses of covariance, and Spearman correlation analyses were applied for the data analyses.

RESULTS

The prevalence rate of suicidality in major depressive disorder amounted to 46.67% (Hamilton Rating Scale for Depression item 3 score ≥1). 53.33% were allocated into the no, 38.44% into the mild/moderate, and 8.23% into the severe suicidality patient group. Due to the stratification of our major depressive disorder patient sample according to different levels of suicidality, we identified some socio-demographic, psychosocial, and clinical variables differentiating from the patient group without suicidality already in presence of mild/moderate suicidality (depressive symptom severity, treatment resistance, psychotic features, add-on medications in general), whereas others separated only when severe suicidality was manifest (inpatient treatment, augmentation with antipsychotics and benzodiazepines, melancholic features, somatic comorbidities).

CONCLUSIONS

As even mild/moderate suicidality is associated with a failure of achieving treatment response, adequate recognition of this condition should be ensured in the clinical practice.

Depression in adolescents and young adults--polysomnographic and neuroendocrine aspects

The comparison of polysomnographic data between a group of nine major depressive adolescents, 12 minor depressive adolescents and 12 controls showed a significant difference in sleep efficiency index and in percentage of awakenings. Sleep efficiency was reduced in major depressive adolescents and the percentage of awakenings was increased. Pubertal stage did not appear to have any effect on sleep EEG recordings. The administration of dexamethasone provoked a suppression of cortisol secretion in 50% of major depressive adolescents. Pubertal stage did not appear to have any significant effect on cortisol level after DST.

Sleep spindle activity changes in patients with affective disorders

Various polysomnographic sleep patterns are associated with affective disorders, but very little is known about sleep spindle characteristics in adult depression. In primary endogenous depressive male patients (unipolar, UP, and bipolar, BP) with comparable depression scores and in normal control subjects recorded during 3 consecutive nights, no night effect was observed on the sleep variables investigated except for REM latencies of stages 1 and 2. Stage 2 duration and variables related to sleep spindle characteristics (the number and the density of spindles of 1/2 s; the number and the density of full spindles of stage 2 over the 3 nights) were significantly lower in depressed patients than in control subjects, the mean number of spindles being lower in UP than in BP patients. Sleep spindle measures were clearly negatively correlated with age in the overall group (i.e., depressed plus control subjects). They were also negatively correlated with the REM latencies of stages 1 and 2 in BP depressed patients, whereas this relation was not observed in UP patients.

Circannual variations in the density of tritiated imipramine binding sites on blood platelets in man

We demonstrate a circannual variation in the density of binding sites of 3H-imipramine on human platelets of normal controls and depressed patients. These results imply further reassessment of previously published data on 3H-imipramine binding studies in affective disorders.