Biomedical subjects

Abraham Weizman

Publications and source records attributed to Abraham Weizman.

At least 19 recordsLinked to original sources

PubMed2007

Analysis of clinical symptomatology, extrapyramidal symptoms and neurocognitive dysfunction following dehydroepiandrosterone (DHEA) administration in olanzapine treated schizophrenia patients: a randomized, double-blind placebo controlled trial.

Several studies have demonstrated the effective use of dehydroepiandrosterone (DHEA) in the management of mood, however studies of its use in psychosis remain limited. The aim of this study was to investigate for the first time efficacy of DHEA augmentation with standardized antipsychotic medication (olanzapine) and to explore effects of DHEA augmentation on side-effect profiles including weight gain, glucose tolerance, aggression, quality of life and neurocognitive function. Finally, we aimed to analyze any relationship between plasma levels and clinical response to DHEA administration. Forty patients with chronic schizophrenia stabilized on olanzapine were randomized in double-blind fashion to receive either DHEA (titrated up to 150mg) or placebo augmentation for a period of 12-weeks. Blood samples were collected at baseline, mid-study and study completion. Results indicated improvement of negative symptoms (SANS scale) even when baseline scores were controlled as a covariate. Some improvement in Parkinsonism and akathisia compared to baseline was seen in patients receiving DHEA. No change in psychosis as reflected by the PANSS was noted. Patients receiving DHEA appeared to demonstrate relatively stable glucose levels compared to controls at the end of the study. An improvement in cognitive performance (most notably memory), which did not reach significance due to low sample number, was observed following DHEA administration. Results further suggest preliminary evidence of involvement of the neurosteroid system in schizophrenia pathophysiology, and confirm initial "cautious" findings identifying an agent capable of improving negative symptoms and certain features of extrapyramidal side effects.

Adolescent↗

PubMed2007

Demographic and clinical characteristics of motor vehicle accident victims in the community general health outpatient clinic: a comparison of PTSD and non-PTSD subjects.

Motor vehicle accidents (MVAs) are the leading cause of posttraumatic stress disorder (PTSD) in the general population, often with enduring symptomatology. This study details epidemiological and clinical features that characterize PTSD among MVA victims living in a nonhospitalized community setting long after the MVA event, and includes exploration of premorbid and peritraumatic factors. MVA victims (n=60; 23 males, 37 females) identified from the registry of a community general health outpatient clinic during a 7-year period were administered an extensive structured battery of epidemiological, diagnostic and clinical ratings. Results indicated that 30 subjects (50%; 12 males, 18 females) had MVA-related PTSD (MVAR-PTSD). Among those with PTSD, 16 individuals exhibited PTSD in partial remission, and six, in full remission. There were no significant demographic or occupational function differences between PTSD and non-PTSD groups. The most common comorbid conditions with MVAR-PTSD were social phobia (20%), generalized anxiety disorder (7.8%) and obsessive-compulsive disorder (0.5%). Previous MVA's were not predictive of PTSD. Subjects with MVAR-PTSD scored worse on the Clinician-Administered Posttraumatic Stress Disorder Scale, Part 2 (CAPS-2), Impact of Event Scale, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, Impulsivity Scale, and Toronto Alexithymia Rating Scale. Study observations indicate a relatively high rate of PTSD following an MVA in a community-based sample. The relatively high rate of partially remitted MVAR-PTSD (N=16) underscores the importance of subsyndromal forms of illness. Alexithymia may be an adaptive method of coping with event stress. The development of PTSD appears not to be associated with the severity of MVA-related physical injury.

Accidents, Traffic↗

PubMed2006

Differences in blood pregnenolone and dehydroepiandrosterone levels between schizophrenia patients and healthy subjects.

BACKGROUND AND OBJECTIVE: Contradictory and confusing reports on serum dehydroepiandrosterone (DHEA) levels in schizophrenia led us to compare the serum concentration of its precursor, pregnenolone (PREG), between medicated schizophrenia patients and healthy subjects. The neurosteroid levels were monitored for two months and the relationship of these neurosteroids with schizophrenic symptomatology, emotional distress, and anxiety was examined. METHOD: We determined blood levels of PREG, and DHEA in 15 schizophrenia patients and 12 healthy controls at four time points: at the start of the study, after 2, 4 and 8 weeks. Analysis of covariance and canonical correlations across four time points were applied. RESULTS: Controlling for age, serum concentrations of PREG were lower, while the DHEA level and the molar ratio values of DHEA/PREG were higher in schizophrenia patients compared to healthy controls. Both levels of PREG and DHEA and their molar ratio did not change significantly during the study's period either among schizophrenia patients or healthy controls. The blood levels of PREG appear to be associated with trait-anxiety scores in the schizophrenia patients, while associations of clinical symptoms with two neurosteroids did not reach a significant level when the confounding effect of emotional distress, and anxiety scores was controlled. CONCLUSION: Low serum pregnenolone concentrations in schizophrenia appear to be associated with trait-anxiety scores independent of symptoms. Further research into the role of pregnenolone in schizophrenia is warranted.

Adult↗

PubMed2006

The protective effect of frontal cortex dehydroepiandrosterone in anxiety and depressive models in mice.

We aimed to verify whether DHEA, a neuoroactive neurosteroid, has a protective role in preventing the occurrence or enhancement of the severity of depression and anxiety in mice. Four groups were tested: controls, mice possessing significantly high frontal cortex DHEA levels, achieved by repeated DHEA injections (1.6 mg/Kg, i.p.), mice that have significantly low frontal cortex DHEA levels, consequent to castration and mice possessing significantly low frontal cortex DHEA levels, treated with DHEA to reverse its level to normal, achieved by castration and repeated DHEA injections (0.4 mg/Kg, i.p.). The Forced Swim Test to determine depressive-like and the Elevated Plus Maze (EPM) to evaluate anxiety-like behaviors, were used. We found that DHEA had an anti-depressive-like effect, as shown by a decreased immobility time in mice possessing a high level of frontal cortex DHEA and increased immobility time in mice that have a low frontal cortex DHEA level. DHEA also demonstrated an anti-anxiety-like effect, as shown by the open-arm time in EPM, which correlated with DHEA level. Mice with significantly low DHEA levels when restored to normal, did not differ from controls. In conclusion, high levels of DHEA have an anti-anxiety-like and an anti-depressive-like effect in mice and those with low levels of frontal cortex DHEA are more vulnerable to depression and/or anxiety.

Animals↗

PubMed2006

State and trait related predictors of serum cortisol to DHEA(S) molar ratios and hormone concentrations in schizophrenia patients.

OBJECTIVE: In previous studies we have demonstrated high serum molar ratios of cortisol to dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) [together abbreviated DHEA(S)], and the value of both cortisol/DHEA(S) molar ratios for prediction of responsivity to antipsychotic treatment in schizophrenia patients. The present study aimed to examine the contribution of anxiety, and severity of symptoms to the prediction of serum cortisol, DHEA(S) levels and two molar ratios across three examinations. METHOD: Serum concentrations of cortisol and DHEA(S)were examined in 43 schizophrenia inpatients and in 20 age matched healthy controls at baseline, and after 2 and 4 weeks. The Positive and Negative Symptom Scale and the State-Trait Anxiety Inventory scores were used as independent variables for multiple regression analysis. RESULTS: Despite clinical improvement during the study period cortisol/DHEA(S) molar ratios were found persistently elevated as compared to healthy controls. Multiple regression analysis revealed that across three examinations cortisol/DHEA(S) molar ratios negatively associated with trait-anxiety (partial R(2)=7-14%) rather than with negative symptoms (partial R(2)=3-6%). Age and age of onset account for 12.7% for variability of cortisol/DHEAS ratio. Serum cortisol concentrations are predicted by trait and state-anxiety, activation symptoms and daily doses of antipsychotics. A small portion of variability in serum DHEA levels (R(2)=9%) is associated with symptom severity, while DHEAS levels were predicted by age at examination and age of onset. CONCLUSION: Elevated serum cortisol/DHEA(S) molar ratios were attributed to trait-anxiety and age rather than to clinical symptoms. The findings may indicate persistent dysfunction of the hypothalamic-pituitary-adrenal axis that is independent of the patients' clinical state.

Adult↗

PubMed2006

Prolactin and estradiol serum levels in unmedicated male paranoid schizophrenia patients.

There is evidence for the involvement of the endocrine system in schizophrenia. This involment was widely investigated in female patients. In the current study, we examined prolactin and estradiol serum levels in hospitalized unmedicated men with first-episode and recurrent schizophrenia and then tested possible correlation with various subtypes of the disease. In addition, the estradiol and prolactin levels were compared with a healthy control group. The serum samples were assessed the morning following admission in fifty-seven schizophrenia male patients. There was a significant difference in prolactin serum levels between the paranoid and "nonparanoid" schizophrenia subgroups. However, no significant differences were found in estradiol serum levels between schizophrenia subtypes or between the patients and their healthy counterparts. Finally, a significant and positive correlation was found between the prolactin and estradiol levels in the paranoid subgroup alone. Thus, it appears that low estradiol levels are associated with low prolactin levels, alleged hyperdopaminergic tone and psychotic breakdown in paranoid schizophrenia. The results of the present study further support our previous report of the association between prolactin serum levels and the schizophrenia cluster subtypes, indicating a different dopaminergic activity for the various forms of the disease.

Adult↗

PubMed2006

Neurosteroids in child and adolescent psychopathology.

Neurosteroids play a significant role in neurodevelopment and are involved in a wide variety of psychopathological processes. There is accumulating evidence on their role in adult psychopathology, including Alzheimer disease, schizophrenia, mood disorder, anxiety disorders and post-traumatic stress disorder. Little is known, however, about the possible role of neurosteroids in child and adolescent psychopathology although there is increasing evidence for their critical role from the early stages of brain development until adolescence. In this review we focus on the involvement of neurosteroids in neurodevelopment and mental disorders in children and adolescents. Adequate physiological levels protect the developing neural system from insult and contribute to the regulation of brain organization and function. Neurosteroids may be involved in the pathophysiology and pharmacotherapy of a variety of disorders in children and adolescents, including schizophrenia, depression, eating disorders, aggressive behavior and attention deficit. The complex interaction between neurosteroids, neurodevelopment, life-events, genetics and mental disorders in children and adolescents merits further investigation.

Adolescent↗

PubMed2006

Serum creatine kinase level in unmedicated nonpsychotic, psychotic, bipolar and schizoaffective depressed patients.

Creatine kinase (CK) level was previously found to be increased in the majority of hospitalized acute psychotic patients. We aimed to asses the possible differences in CK level in various forms of depression: major with and without psychotic symptoms, of bipolar depression and schizoaffective depression. Unmedicated hospitalized patients participated: nonpsychotic major depression (n=39), psychotic major depression (n=23), bipolar depression (n=23) and schizoaffective depression (n=24). The severity of depression was assessed by the Hamilton Depression Rating Scale (Ham-D) and blood samples were collected in the morning of admission day, prior to any treatment. Ham-D yielded a significantly higher score for psychotic major depression group, compared with all other groups which showed similar score. CK serum level was significantly higher in nonpsychotic major depression than in all other forms of depression. The results indicate a biological difference between the nonpsychotic major depression and the "psychotic" cluster of depressive syndromes.

Adolescent↗

PubMed2006

Association of the serotonin transporter promotor polymorphism with suicide attempters with a high medical damage.

Serotonergic neurotransmission has been implicated in suicidal behavior, including inconsistent results concerning the serotonin transporter promoter polymorphism (5-HTTLPR). Here, we analyzed the 5-HTTLPR in suicide attempters (n=85). Comparing the presence of SS with SL+LL genotypes showed a significantly higher prevalence of the SS genotype in suicide attempters with high medical damage scores (chi2=9.054, df=1, p=0.0026). The results suggest that the S-allele may predispose for suicidal behavior characterized by high determination.

Adult↗

PubMed2006

Psychological and cytokine changes in children and adolescents undergoing hematopoietic stem cell transplantation.

BACKGROUND: Hematopoietic stem cell transplantation is a therapeutic option of a large variety of diseases. It involves several physiological and psychological changes. Investigations of mood changes in patients undergoing hematopoietic stem cell transplantation are common. There are no studies however, on the relationship between changes in mood and physiological changes in hematopoietic stem cell transplantation in children and adolescents. We investigated the correlation between anxiety, depression and serum Interleukin-1beta (IL-1beta), IL-2 and IL-6. METHODS: Participants, 11 boys and 12 girls, aged 6-18 years, were administered the Children Depression Inventory (CDI) and the Spielberger State Anxiety Inventory for Children (SAIC), at four different points in time: at conditioning time when treatment is initiated (time 1 = T1), on the day of hematopoietic transplantation (T2), on the day of engraftment (T3) and a week after the engraftment (T4). At each of those times serum samples for cytokines determination were collected as well. RESULTS: Up to the time of engraftment depression and anxiety were relatively high but resolved subsequently. Globally, there was a significant time effect for anxiety (p = 0.0082). Namely, scores differ between times. Depression showed a similar trend, though this trend did not reach significance (p = 0.1394). Negative correlation was found between serum IL-1beta, IL-2 and IL-6 levels and anxiety (IL-2 and IL-6) and depression scores (IL-1beta and IL-2) at T4. The complex interaction between cytokines, depression and anxiety in children and adolescents undergoing hematopoietic stem cell transplantation merits further long-term studies under natural conditions and on laboratory models.

Adolescent↗

PubMed2006

Translocator protein (18kDa): new nomenclature for the peripheral-type benzodiazepine receptor based on its structure and molecular function.

The peripheral-type benzodiazepine receptor or recognition site (PBR) is a widely distributed transmembrane protein that is located mainly in the outer mitochondrial membrane. The PBR binds to high-affinity drug ligands and cholesterol. Many functions are associated directly or indirectly with the PBR, including the regulation of cholesterol transport and the synthesis of steroid hormones, porphyrin transport and heme synthesis, apoptosis, cell proliferation, anion transport, regulation of mitochondrial functions and immunomodulation. Based on these functions, there are many potential clinical applications of PBR modulation, such as in oncologic, endocrine, neuropsychiatric and neurodegenerative diseases. Although "PBR" is a widely used and accepted name in the scientific community, recent data regarding the structure and molecular function of this protein increasingly support renaming it to represent more accurately its subcellular role (or roles) and putative tissue-specific function (or functions). Translocator protein (18kDa) is proposed as a new name, regardless of the subcellular localization of the protein.

Animals↗

PubMed2006

A 10-year retrospective study of inpatient adolescents with schizophrenia/schizoaffective disorder and substance use.

The comorbidity of schizophrenia/schizoaffective disorder and substance use is a major psychiatric concern that is associated with aggressive and suicidal behavior. This study investigated the clinical correlates and characterizes adolescent psychotic inpatients with and without comorbid substance use. We performed a retrospective study of 188 adolescent inpatients who were admitted between the years 1994 and 2004 to the inpatient unit of Geha Mental Health Center and who were diagnosed as suffering from either schizophrenia or schizoaffective disorder. The substance-using psychotic inpatients were found to have more relatives with substance-related disorders, fewer comorbid anxiety disorders, lower scores on the Brief Psychiatric Rating Scale and Hamilton Scale for Depression, higher scores on the Overt Aggression Scale, and they were more suicidal than the nonsubstance using inpatients. Adolescent inpatients with schizophrenia and schizoaffective who use substances possess differential clinical characteristics and particular correlates that justify adopting a specific approach to this high-risk clinical subgroup.

Adolescent↗

PubMed2006

Obsessive-compulsive disorder in bipolar disorder patients with first manic episode.

BACKGROUND: Evidence indicates that obsessive--compulsive disorder (OCD) co-occurs with schizophrenia and bipolar disorder (BD) at a higher rate than in the general population. The inflated rate of comorbidity may result from chronic illness, antipsychotic therapy or treatment-seeking behavior. To control for these factors we evaluated the prevalence of OCD in patients with first-episode acute mania who met DSM-IV criteria for BD-I, and compared them with our previously reported group of first-episode schizophrenia patients. METHOD: Fifty-six BD-I patients with a first-episode of acute mania were screened for OCD and additional comorbid disorders using the Structured Clinical Interview for DSM-IV Axis-I disorders and appropriate rating scales. RESULTS: Only one patient (1.8%) met DSM-IV criteria for OCD, and two (3.6%) met criteria for sub-threshold OCD. In contrast, there was a substantial aggregation of substance use disorders 32.1% (N=8), anxiety disorders, other than OCD 26.8% (N=15) and eating disorders 14.3% (N=8). LIMITATIONS: Small sample size, cross-sectional nature of the assessments and the inclusion of only BD-I patients. CONCLUSION: The rate of OCD in first-episode BD-I patients did not differ significantly from that found in the general population and was substantially lower than in previously reported first-episode schizophrenia patients (1.8% vs. 14%). We suggest that a preferential association of OCD with schizophrenia early in the course of illness represents a pathophysiological linkage between the two disorders, and putatively a specific schizo-obsessive subtype. In contrast, OCD in BD-I may stand for "true" comorbidity. Large-scale parallel comparative evaluations of comorbidity in BD-I and schizophrenia may contribute to the search for specific pathophysiological mechanisms of distinct comorbid-related subsets in either disorder.

Acute Disease↗

PubMed2006

Association of the low-activity COMT 158Met allele with ADHD and OCD in subjects with velocardiofacial syndrome.

Velocardiofacial syndrome (VCFS) is caused by a microdeletion in chromosome 22 and is a risk factor for the development of schizophrenia and other psychiatric disorders. The catechol-O-methyltransferase (COMT), residing in the 22q11.2 microdeletion region, is a major candidate gene for genetic susceptibility to neuropsychiatric disorders in VCFS. Individuals with VCFS carrying the low-activity allele (COMTL) are expected to have the lowest possible COMT activity since they have only a single copy of the gene. We explored the possibility that COMTL is associated with psychiatric disorders commonly found in VCFS. Fifty-five unrelated individuals with VCFS underwent psychiatric evaluation and were genotyped for the COMT 158Val/Met polymorphism coding for COMT high/low-activity alleles. The COMTL allele was significantly more prevalent in VCFS subjects with attention deficit hyperactivity disorder (ADHD) (73.9% vs. 33.3%, OR 5.67, chi2=7.76, p=0.005) and obsessive-compulsive disorder (OCD) (78.6% vs. 33.3%, OR 7.33, chi2=7.24, p=0.007) than in the control group (VCFS subjects without OCD, ADHD and schizophrenia/schizoaffective (SZ/SZaff) disorder). The results of this study suggest that greatly reduced COMT activity, as expected in VCFS COMTL individuals may be a risk factor for psychiatric sequelae in this population. Future longitudinal studies focusing on additional COMT polymorphic sites and other candidate genes from the deleted region will elucidate the molecular pathways leading to schizophrenia and other psychiatric disorders in VCFS.

Adolescent↗

PubMed2006

Serotonin transporter characteristics in lymphocytes and platelets of male aggressive schizophrenia patients compared to non-aggressive schizophrenia patients.

A large body of literature indicates that disturbances of central serotonin (5-HT) function play an important role in aggressive behavior. Results from open-label and placebo-controlled trials as well as the reported inverse relationship between 5-HT function and aggression in human subjects, suggest that reduced 5-HT activity is associated with aggressive behavior. The activity of the 5-HT transporter (5-HTT), as determined by [(3)H]5-HT uptake to blood lymphocytes, was measured in 20 currently aggressive and 20 non-aggressive male schizophrenia patients. In addition, the pharmacodynamic characteristics of platelet 5-HTT were assessed by [(3)H]citalopram binding. There were no significant differences in the density (B(max)) of platelet [(3)H]citalopram binding sites between the two groups. Similarly, the dissociation constant (K(d)) values were indistinguishable. The maximum uptake velocity (V(max)) of [(3)H]5-HT to fresh lymphocytes and the K(m) values of the 5-HT to the transporter were significantly higher in currently aggressive compared to the non-aggressive schizophrenia patients. The association of high V(max) values with current aggressive behavior provides further support to the involvement of the 5-HTT in aggressive behavior as well as to the efficacy of 5-HTT blockers in the control of aggression. The role of the various components of the serotonergic system in the pathophysiology and treatment of aggressive behavior in schizophrenia needs to be further evaluated.

Adult↗

PubMed2006

Thyroxine-triiodothyronine combination therapy versus thyroxine monotherapy for clinical hypothyroidism: meta-analysis of randomized controlled trials.

CONTEXT: In some patients symptoms of hypothyroidism persist despite therapy with T(4). OBJECTIVE: The objective of the study was to compare the effectiveness of T(4)-T(3) combination vs. T(4) monotherapy for the treatment of clinical hypothyroidism in adults. DATA SOURCES: PubMed, EMBASE, LILACS, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched in September 2005. References of all included trials were scanned for additional studies. We put no restrictions on language, year of publication, or publication status. STUDY SELECTION: All randomized trials that compared the effectiveness of T(4)-T(3) combination vs. T(4) monotherapy for the treatment of clinical hypothyroidism in adults were included. DATA EXTRACTION: The data were extracted by two independent reviewers. DATA SYNTHESIS: We included 11 studies, in which 1216 patients were randomized. No difference was found in the effectiveness of combination vs. monotherapy in any of the following symptoms: bodily pain [standardized mean difference (SMD) 0.00, 95% confidence interval (CI) -0.34, 0.35], depression (SMD 0.07, 95% CI -0.20, 0.34), anxiety (SMD 0.00, 95% CI -0.12, 0.11), fatigue (SMD -0.12, 95% CI -0.33, 0.09), quality of life (SMD 0.03, 95% CI -0.09, 0.15), body weight, total serum cholesterol, triglyceride levels, low-density lipoprotein, and high-density lipoprotein. Adverse events did not differ between regimens. CONCLUSIONS: T(4) monotherapy should remain the treatment of choice for clinical hypothyroidism.

Adult↗

PubMed2006

Low-dose mirtazapine: a new option in the treatment of antipsychotic-induced akathisia. A randomized, double-blind, placebo- and propranolol-controlled trial.

BACKGROUND: Preliminary evidence indicates a beneficial effect of serotonin 2A (5-HT(2A)) receptor antagonists in antipsychotic-induced akathisia (AIA). We investigated the antiakathisia effect, safety, and tolerability of low-dose mirtazapine, an agent with marked 5-HT(2A) antagonism. METHODS: In a 7-day double-blind trial, 90 antipsychotic-treated patients meeting DSM-IV criteria for AIA were randomly assigned to mirtazapine (n = 30; 15 mg), propranolol (n = 30; 80 mg), or placebo (n = 30). Primary outcome measures were between-group differences in Barnes Akathisia Scale (BAS) global scores and in the proportion of responders (reduction of > or = 2 points on BAS). Analysis was by intention to treat. RESULTS: Twenty-four patients (26.6%) who were assigned treatment did not complete the study (7 mirtazapine, 8 propranolol, 9 placebo), due to lack of response (n = 19) and adverse events (n = 5). Both mirtazapine and propranolol significantly reduced AIA severity (BAS: -34% mirtazapine and -29% propranolol vs. placebo -11%; p = .012 and p = .023, respectively). Thirteen (43.3%) mirtazapine and 9 (30.0%) propranolol-treated patients versus 2 (6.7%) placebo-treated patients responded (the corresponding odds ratios 10.7 [95% confidence interval (CI), 2.1-53.3] and 6.0 [95% CI, 1.1-30.7]). Five (16.7%) of 30 propranolol-treated patients and none in the mirtazapine and placebo groups (p = .0195 for both) prematurely discontinued the study due to clinically significant hypotension or bradycardia. CONCLUSIONS: The comparable efficacy and better tolerability of low-dose mirtazapine versus propranolol, the current first-line treatment for AIA, position mirtazapine as a favorable candidate for the treatment of acute AIA and may improve current therapeutic practices.

Adult↗

PubMed2006

Characterization of the serotonin transporter in lymphocytes and platelets of schizophrenia patients treated with atypical or typical antipsychotics compared to healthy individuals.

A rapidly growing body of data suggests that abnormalities in serotonergic function might be involved in the pathophysiology of schizophrenia and that serotonergic mechanisms play a role in the therapeutic effects of antipsychotics. The activity of the serotonin transporter (5-HTT), as determined by [(3)H]5-HT uptake to blood lymphocytes, was measured in 38 medicated schizophrenia patients (15 of them treated with typical antipsychotics and 23 treated with atypical antipsychotics) and 15 healthy control subjects. In addition, the pharmacodynamic characteristics of platelet 5-HTT were assessed by [(3)H]citalopram binding. There were no significant differences in the density (B(max)) of platelet [(3)H]citalopram binding sites between the three groups. Similarly, the dissociation constant (K(d)) values were indistinguishable. There were no significant differences in the maximal uptake velocity (V(max)) of [(3)H]5-HT to fresh lymphocytes between the three groups. The affinity (K(m)) values of 5-HT to the 5-HTT were significantly higher in schizophrenia patients treated with typical antipsychotics compared with control subjects. The K(m) values in schizophrenia patients treated with atypical antipsychotics were significantly lower compared with those observed in the group of schizophrenia patients treated with typical antipsychotics; however, they were comparable to values in the control group. The high values of K(m) associated with typical antipsychotic treatment may be relevant to the high risk of developing extrapyramidal side effects (EPS). The role of the various components of the serotonergic system in the etiopathology of schizophrenia and the mechanisms by which antipsychotics achieve their therapeutic effects need to be further evaluated.

Adult↗