Flupenthixol versus risperidone: subjective quality of life as an important factor for compliance in chronic schizophrenic patients

Meet the relatives: a reintroduction to the clinical pharmacology of ‘typical’ antipsychotics (Part 2)

This second of two articles on the ‘typical’ (‘first-generation’) antipsychotics covers non-phenothiazines: thioxanthenes (flupentixol and zuclopenthixol), butyrophenones/diphenylbutylpiperidines (including one-time world market-leader haloperidol, and pimozide) and sulpiride, for many years the only substituted benzamide available in the UK. Several tolerability issues ascribed specifically or more frequently to older antipsychotics are also discussed.

Dorsal striatal volumes in never-treated patients with first-episode schizophrenia before and during acute treatment

BACKGROUND

Studies of pre-and post-treatment striatal volume in schizophrenia have reported conflicting results.

MATERIALS AND METHODS

We assessed dorsal striatal (caudate and putamen) volumes bilaterally in 22 never-treated, non-substance-abusing patients with first-episode schizophrenia or schizophreniform disorder and 23 healthy controls matched for age, sex and educational status. Patients received either risperidone or flupenthixol long acting injection and were compared by structural MRI with controls at weeks 0, 4 and 13. T1-weighted data on a 3T MRI scanner were obtained and images were reconstructed using FreeSurfer. Treatment outcome was assessed by changes in psychopathology, insight, functionality, cognitive performance and motor symptoms.

RESULTS

Caudate, but not putamen volumes was significantly larger in patients bilaterally at baseline (P=0.01). Linear mixed effects repeated measures found no significant group × time interactions for any of the regions. Caudate volume was not significantly associated with improvements in psychotic symptoms. Also, the findings of a regression model were inconsistent insofar as larger caudate volume was associated with less improvement in depression scores, greater improvement in functionality and greater improvement in verbal learning but less improvement in reasoning and problem solving (left caudate) and composite cognitive score (right caudate).

CONCLUSIONS

The increased caudate volumes prior to treatment are contrary to previous reports in never-treated patients with first-episode schizophrenia, and together with our failure to demonstrate volume changes related to acute treatment, call into question previous proposals that enlarged caudate volume is a consequence of antipsychotic treatment.

Interventions for enhancing medication adherence

BACKGROUND

People who are prescribed self administered medications typically take only about half their prescribed doses. Efforts to assist patients with adherence to medications might improve the benefits of prescribed medications.

OBJECTIVES

The primary objective of this review is to assess the effects of interventions intended to enhance patient adherence to prescribed medications for medical conditions, on both medication adherence and clinical outcomes.

SEARCH METHODS

We updated searches of The Cochrane Library, including CENTRAL (via http://onlinelibrary.wiley.com/cochranelibrary/search/), MEDLINE, EMBASE, PsycINFO (all via Ovid), CINAHL (via EBSCO), and Sociological Abstracts (via ProQuest) on 11 January 2013 with no language restriction. We also reviewed bibliographies in articles on patient adherence, and contacted authors of relevant original and review articles.

SELECTION CRITERIA

We included unconfounded RCTs of interventions to improve adherence with prescribed medications, measuring both medication adherence and clinical outcome, with at least 80% follow-up of each group studied and, for long-term treatments, at least six months follow-up for studies with positive findings at earlier time points.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted all data and a third author resolved disagreements. The studies differed widely according to medical condition, patient population, intervention, measures of adherence, and clinical outcomes. Pooling results according to one of these characteristics still leaves highly heterogeneous groups, and we could not justify meta-analysis. Instead, we conducted a qualitative analysis with a focus on the RCTs with the lowest risk of bias for study design and the primary clinical outcome.

MAIN RESULTS

The present update included 109 new RCTs published since the previous update in January 2007, bringing the total number of RCTs to 182; we found five RCTs from the previous update to be ineligible and excluded them. Studies were heterogeneous for patients, medical problems, treatment regimens, adherence interventions, and adherence and clinical outcome measurements, and most had high risk of bias. The main changes in comparison with the previous update include that we now: 1) report a lack of convincing evidence also specifically among the studies with the lowest risk of bias; 2) do not try to classify studies according to intervention type any more, due to the large heterogeneity; 3) make our database available for collaboration on sub-analyses, in acknowledgement of the need to make collective advancement in this difficult field of research. Of all 182 RCTs, 17 had the lowest risk of bias for study design features and their primary clinical outcome, 11 from the present update and six from the previous update. The RCTs at lowest risk of bias generally involved complex interventions with multiple components, trying to overcome barriers to adherence by means of tailored ongoing support from allied health professionals such as pharmacists, who often delivered intense education, counseling (including motivational interviewing or cognitive behavioral therapy by professionals) or daily treatment support (or both), and sometimes additional support from family or peers. Only five of these RCTs reported improvements in both adherence and clinical outcomes, and no common intervention characteristics were apparent. Even the most effective interventions did not lead to large improvements in adherence or clinical outcomes.

AUTHORS' CONCLUSIONS

Across the body of evidence, effects were inconsistent from study to study, and only a minority of lowest risk of bias RCTs improved both adherence and clinical outcomes. Current methods of improving medication adherence for chronic health problems are mostly complex and not very effective, so that the full benefits of treatment cannot be realized. The research in this field needs advances, including improved design of feasible long-term interventions, objective adherence measures, and sufficient study power to detect improvements in patient-important clinical outcomes. By making our comprehensive database available for sharing we hope to contribute to achieving these advances.

Flupentixol use and adverse reactions in comparison with other common first- and second-generation antipsychotics: data from the AMSP study

This study compares the first-generation antipsychotic (FGA) flupentixol to haloperidol and common second-generation antipsychotics (SGAs) as to drug utilization and severe adverse drug reactions (ADRs) in clinical treatment of schizophrenia inpatients using data from the drug safety program Arzneimittelsicherheit in der Psychiatrie (AMSP). AMSP drug utilization and reported ADR data were analyzed. Type and frequency of severe ADRs attributed to flupentixol were compared with haloperidol, clozapine, olanzapine, quetiapine, risperidone and amisulpride in a total of 56,861 schizophrenia inpatients exposed to these drugs. In spite of increasing prescription of SGAs, flupentixol was consistently used in schizophrenic inpatients (about 5 %) over time. Reporting rates of severe ADR ranged from 0.38 to 1.20 % for the individual antipsychotics (drugs imputed alone); flupentixol ranked lowest. The type of ADR differed considerably; as to severe EPMS, flupentixol (0.27 %), such as risperidone (0.28 %), held an intermediate position between haloperidol/amisulpride (0.55/0.52 %) and olanzapine/quetiapine (<0.1 %). The study is a heuristic approach, not a confirmatory test. Flupentixol has a stable place in the treatment of schizophrenia in spite of the introduction of different SGAs. Comparative ADR profiles suggest an intermediate position between FGAs and SGAs for flupentixol in clinical practice.

Cost-effectiveness of long-acting injectable risperidone versus flupentixol decanoate in the treatment of schizophrenia: a Markov model parameterized using administrative data

We use longitudinal patient-level data from a German sickness fund with 7.26 million insured in a Markov-simulation model to assess the cost-effectiveness of long-acting injectable risperidone (LAI-RIS) compared with long-acting injectable flupentixol (LAI-FLX) in the long-term management of schizophrenia. We simulate treatment costs from the payer's perspective, hospitalization, the probability to be prescribed co-medication, and treatment discontinuation over a 2-year time horizon. Model inputs were derived from 935 patients hospitalized with schizophrenia between 2005 and 2008 who received either LAI-RIS or LAI-FLX for at least 1 month. After 2 years, 89.4% (95.8%) of patients who were initiated on LAI-RIS (LAI-FLX) discontinued the initial regimen. The number of days spent in hospital per month and patient was slightly lower with LAI-RIS (1.08 vs. 1.28 days, p<0.001). The proportion of patients receiving side-effect co-medication was lower with LAI-RIS (8.3 vs. 15.0% per month, p<0.001). Mean total costs of treatment per patient and month were 1,015 € under LAI-RIS and 395 € under LAI-FLX, resulting in an ICER of 3,088 € (95% CI [-913 €; 3,551 €]) for an avoided hospital day per patient and month in the base case scenario with a 15.1% probability of LAI-FLX being the dominant treatment strategy. Cost differences were mainly attributable to the higher drug costs of LAI-RIS. The effectiveness of LAI-RIS in preventing hospital days appears to be similar to LAI-FLX, with a slight superiority in side-effect and switching rates. This comes at the cost of substantially higher treatment expenses. From a decision-maker's point of view, the use of health insurance data as a source of input for decision models appears to be a reasonable alternative to models driven by clinical data only.

Effectiveness and costs of flupentixol compared to other first- and second-generation antipsychotics in the treatment of schizophrenia

RATIONALE

The purpose of this study is to analyse the effectiveness of flupentixol compared to other first- and second-generation antipsychotics for the treatment of schizophrenia in routine care.

METHOD

A retrospective cohort study was conducted using administrative data from four sickness funds covering 12.6 million insured. Patients discharged from hospital in 2003 with an ICD-10 diagnosis of schizophrenia were followed for 12 months. Rehospitalisation during follow-up was analysed using a hurdle regression model. Treatment costs were defined as cost of pharmaceutical and cost of inpatient care. Two thousand eight hundred ninety insured were included, of which 177 were treated with flupentixol during follow-up, while 429 and 2,284 were treated with other first-and second-generation antipsychotics, respectively.

RESULTS

Compared to patients treated with flupentixol (21.0 days), predicted hospitalisation did not differ significantly for patients treated with other first- (21.3 days, p = 0.8313) or second-generation antipsychotics (25.6 days, p = 0.4035). Predicted treatment costs for the average patient were 4,193 Euro if treated with flupentixol, 4,846 Euro if treated with other first-generation antipsychotic, and 6,523 Euro if treated with a second-generation antipsychotic. Second-generation antipsychotics showed a clear advantage over flupentixol concerning extrapyramidal symptoms co-medication.

CONCLUSION

The effectiveness of flupentixol preventing relapse in patients with schizophrenia appears to be similar to that of other first- and second-generation antipsychotics. However, the low treatment costs for patients treated with flupentixol could be explained by the small number of patients with readmissions (70 insured) and the larger share of patients treated with its depot formulation.

Long-term treatment with flupentixol results of a post-marketing surveillance study

Schizophrenia is one of the most expensive illnesses. Antipsychotics are an essential component of the acute and preventative treatment of this illness, and long-term treatment is necessary to decrease the risk of psychotic relapse. The efficacy and tolerability of flupentixol was evaluated in a post-marketing surveillance study (PMS) in schizophrenic patients receiving long-term treatment in routine clinical practice. Psychiatrists in office practice treated patients for approximately 10 weeks, with a subsequent follow-up period of up to 18 months. We here report on the follow-up period in 128 patients. The benefit for schizophrenic patients increased with the treatment duration of flupentixol as documented by the Clinical Global Impression (CGI). Subjective quality of life improved during the first study period, and this remained stable in the follow-up period. No increase in body weight was observed during the study. The relapse rate was much lower than in other studies. Anticholinergic medication was necessary for 22.7% of the patients at any time. More than 70% of the psychiatrists involved evaluated the treatment as very good or good. The results of this study suggest that flupentixol is a potent and safe antipsychotic for the long-term treatment of schizophrenia in routine clinical practice.

Clinical trial: a randomized controlled cross-over study of flupenthixol + melitracen in functional dyspepsia

BACKGROUND

Functional dyspepsia is a prevalent condition associated with diminished quality of life (QoL) and high economic burden.

AIM

To study the efficacy of a combination of flupenthixol and melitracen (F + M) with anxiolytic and antidepressant properties in functional dyspepsia using a randomized controlled cross-over design.

METHODS

Patients met the Rome III criteria for functional dyspepsia and a validated questionnaire was used to exclude those with anxiety or depression. Moreover, patients had to have failed a trial of acid-suppressive therapy and Helicobacter pylori eradication when positive. End points included subjective global symptom relief and QoL assessed by the Nepean Dyspepsia Index (NDI).

RESULTS

Twenty-five patients (14 females, 11 males; mean age = 34.3 +/- 9.9 years) were enrolled and 24 completed the 8-week study. There was a significant improvement in subjective global symptom relief with F + M vs. placebo (ITT: 73.9% vs. 26.1%, P = 0.001) and a significant drop in the NDI score vs. placebo (ITT: -9.0 +/- 11.9 vs. -2.4 +/- 8.9, P = 0.03). No difference was noted whether the initial treatment was F + M or placebo. No significant side effects were noted.

CONCLUSIONS

A combination of F and M is safe and effective in the short-term treatment of functional dyspepsia. F + M is associated with significant improvement in QoL independent of the presence of anxiety or depression.

Interventions for enhancing medication adherence

BACKGROUND

People who are prescribed self-administered medications typically take less than half the prescribed doses. Efforts to assist patients with adherence to medications might improve the benefits of prescribed medications, but also might increase their adverse effects.

OBJECTIVES

To update a review summarizing the results of randomized controlled trials (RCTs) of interventions to help patients follow prescriptions for medications for medical problems, including mental disorders but not addictions.

SEARCH STRATEGY

We updated searches of The Cochrane Library, MEDLINE, CINAHL, EMBASE, International Pharmaceutical Abstracts (IPA), PsycINFO (all via OVID) and Sociological Abstracts (via CSA) in January 2007 with no language restriction. We also reviewed bibliographies in articles on patient adherence and articles in our personal collections, and contacted authors of relevant original and review articles.

SELECTION CRITERIA

Articles were selected if they reported an unconfounded RCT of an intervention to improve adherence with prescribed medications, measuring both medication adherence and treatment outcome, with at least 80% follow-up of each group studied and, for long-term treatments, at least six months follow-up for studies with positive initial findings.

DATA COLLECTION AND ANALYSIS

Study design features, interventions and controls, and results were extracted by one review author and confirmed by at least one other review author. We extracted adherence rates and their measures of variance for all methods of measuring adherence in each study, and all outcome rates and their measures of variance for each study group, as well as levels of statistical significance for differences between study groups, consulting authors and verifying or correcting analyses as needed. The studies differed widely according to medical condition, patient population, intervention, measures of adherence, and clinical outcomes. Therefore, we did not feel that quantitative analysis was scientifically justified; rather, we conducted a qualitative analysis.

MAIN RESULTS

For short-term treatments, four of ten interventions reported in nine RCTs showed an effect on both adherence and at least one clinical outcome, while one intervention reported in one RCT significantly improved patient adherence, but did not enhance the clinical outcome. For long-term treatments, 36 of 81 interventions reported in 69 RCTs were associated with improvements in adherence, but only 25 interventions led to improvement in at least one treatment outcome. Almost all of the interventions that were effective for long-term care were complex, including combinations of more convenient care, information, reminders, self-monitoring, reinforcement, counseling, family therapy, psychological therapy, crisis intervention, manual telephone follow-up, and supportive care. Even the most effective interventions did not lead to large improvements in adherence and treatment outcomes.

AUTHORS' CONCLUSIONS

For short-term treatments several quite simple interventions increased adherence and improved patient outcomes, but the effects were inconsistent from study to study with less than half of studies showing benefits. Current methods of improving adherence for chronic health problems are mostly complex and not very effective, so that the full benefits of treatment cannot be realized. High priority should be given to fundamental and applied research concerning innovations to assist patients to follow medication prescriptions for long-term medical disorders.

'Real world' comparison of first- and second-generation antipsychotics in regard to length of inpatient hospitalization and number of re-hospitalizations

The purpose of this study was to determine if Second-Generation Antipsychotics (SGAs), relative to First-Generation Antipsychotics (FGAs), reduced either the length of stay (LOS) or number of re-hospitalizations of schizophrenic patients receiving treatment in a state psychiatric hospital. Medical records were compared for the periods 1991-1994 and 2001-2004 for three inpatient groups: those receiving FGAs, those receiving SGAs, and those switched from FGAs to SGAs. During both time periods, patients on FGAs had significantly shorter LOS than either those receiving SGAs or those switched from FGAs to SGAs. Therefore, inpatients receiving SGAs were hospitalized longer than those receiving FGAs. Conversely, once discharged, patients receiving SGAs were significantly less likely to be re-admitted than patients discharged on FGAs. The data suggest that some patients do benefit from SGAs and it may be cost-effective in the long-term, to determine when to utilize FGAs first and when to switch from the older to the newer agents.

Quality of life in schizophrenic patients

In the last decades, there has been increased interest in the field of quality of life in mental disorders in general, and particularly in schizophrenia. In addition, the appearance of the atypical antipsychotic drugs (amisul pride, aripiprazole, clozapine, olanzapine, quetiapine, risperidone, and ziprasidone) with different therapeutic and side-effect profiles, has promoted a greater interest in assessing the quality of life of schizophrenic patients. In this paper we will briefly summarize the difficulties in assessing quality of life in schizophrenic patients, as well as the results concerning their quality of life and the influence of psychopathology, especially negative and depressive symptoms, on it. We will also review data from recent clinical trials showing the impact of antipsychotic treatments and their side effects upon quality of life.

Efficacy of flupentixol and risperidone in chronic schizophrenia with predominantly negative symptoms

The study investigated the non-inferiority of flupentixol compared to risperidone in the treatment of negative symptoms. In addition, the effects of flupentixol on mood and cognitive symptoms were explored. In a randomized, double-blind multicenter study, 144 non-acute schizophrenia patients with predominant negative symptoms were treated with a flexible dose of either flupentixol (4-12 mg/d) or risperidone (2-6 mg/d) for up to 25 weeks. In addition to a non-inferiority analysis, a principal component analysis (PCA) of the PANSS was performed post hoc. Regarding negative symptoms, flupentixol proved to be non-inferior to risperidone. Both drugs improved depressed mood with effect sizes favoring flupentixol. PCA suggested a five-factor structure. Effect sizes for the cognitive factor were up to 0.74 for flupentixol and up to 0.80 for risperidone. EPS scores were rather low and Parkinsonism improved in both groups, but anticholinergic drugs were prescribed significantly more frequently in the flupentixol group, which generally showed significantly more adverse events. Results indicate that the 1st generation antipsychotic flupentixol improves negative, affective and cognitive symptoms in chronic schizophrenia comparable to risperidone. Further studies should confirm the latter using neuropsychological performance tests and should investigate whether tolerability improves with a markedly lower dose range.

Defining and assessing adherence to oral antipsychotics: a review of the literature

The definition and assessment of adherence vary considerably across studies. Increasing consensus regarding these issues is necessary to improve our understanding of adherence and the development of more effective treatments. We review the adherence literature over the past 3 decades to explore the definitions and assessment of adherence to oral antipsychotics in schizophrenia patients. A total of 161 articles were identified through MEDLINE and PsycINFO searches. The most common method used to assess adherence was the report of the patient. Subjective and indirect methods including self-report, provider report, significant other report, and chart review were the only methods used to assess adherence in over 77% (124/161) of studies reviewed. Direct or objective measures including pill count, blood or urine analysis, electronic monitoring, and electronic refill records were used in less than 23% (37/161) of studies. Even in studies utilizing the same methodology to assess adherence, definitions of an adherent subject varied broadly from agreeing to take any medication to taking at least 90% of medication as prescribed. We make suggestions for consensus development, including the use of recommended terminology for different subject samples, the increased use of objective or direct measures, and the inclusion in all studies of an estimate of the percentage of medication taken as prescribed in an effort to increase comparability among studies. The suggestions are designed to advance the field with respect to both understanding predictors of adherence and developing interventions to improve adherence to oral antipsychotic medications.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for biological treatment of schizophrenia, part 2: long-term treatment of schizophrenia

These guidelines for the biological treatment of schizophrenia were developed by an international Task Force of the World Federation of Societies of Biological Psychiatry (WFSBP). The goal during the development of these guidelines was to review systematically all available evidence pertaining to the treatment of schizophrenia, and to reach a consensus on a series of practice recommendations that are clinically and scientifically meaningful based on the available evidence. These guidelines are intended for use by all physicians seeing and treating people with schizophrenia. The data used for developing these guidelines have been extracted primarily from various national treatment guidelines and panels for schizophrenia, as well as from meta-analyses, reviews and randomised clinical trials on the efficacy of pharmacological and other biological treatment interventions identified by a search of the MEDLINE database and Cochrane Library. The identified literature was evaluated with respect to the strength of evidence for its efficacy and then categorised into four levels of evidence (A-D). This second part of the guidelines covers the long-term treatment as well as the management of relevant side effects. These guidelines are primarily concerned with the biological treatment (including antipsychotic medication, other pharmacological treatment options, electroconvulsive therapy, adjunctive and novel therapeutic strategies) of adults suffering from schizophrenia.

Interventions to enhance medication adherence

BACKGROUND

People who are prescribed self-administered medications typically take less than half the prescribed doses. Efforts to assist patients with adherence to medications might improve the benefits of prescribed medications, but also might increase their adverse effects.

OBJECTIVES

To update a review summarizing the results of randomized controlled trials (RCTs) of interventions to help patients follow prescriptions for medications for medical problems, including mental disorders but not addictions.

SEARCH STRATEGY

Computerized searches were updated to September 2004 without language restriction in MEDLINE, EMBASE, CINAHL, The Cochrane Library, International Pharmaceutical Abstracts (IPA), PsycINFO and SOCIOFILE. We also reviewed bibliographies in articles on patient adherence and articles in our personal collections, and contacted authors of original and review articles on the topic.

SELECTION CRITERIA

Articles were selected if they reported an unconfounded RCT of an intervention to improve adherence with prescribed medications, measuring both medication adherence and treatment outcome, with at least 80% follow-up of each group studied and, for long-term treatments, at least six months follow-up for studies with positive initial findings.

DATA COLLECTION AND ANALYSIS

Study design features, interventions and controls, and results were extracted by one reviewer and confirmed by at least one other reviewer. We extracted adherence rates and their measures of variance for all methods of measuring adherence in each study, and all outcome rates and their measures of variance for each study group, as well as levels of statistical significance for differences between study groups, consulting authors and verifying or correcting analyses as needed.

MAIN RESULTS

For short-term treatments, four of nine interventions reported in eight RCTs showed an effect on both adherence and at least one clinical outcome, while one intervention reported in one RCT significantly improved patient compliance, but did not enhance the clinical outcome. For long-term treatments, 26 of 58 interventions reported in 49 RCTs were associated with improvements in adherence, but only 18 interventions led to improvement in at least one treatment outcome. Almost all of the interventions that were effective for long-term care were complex, including combinations of more convenient care, information, reminders, self-monitoring, reinforcement, counseling, family therapy, psychological therapy, crisis intervention, manual telephone follow-up, and supportive care. Even the most effective interventions did not lead to large improvements in adherence and treatment outcomes. Six studies showed that telling patients about adverse effects of treatment did not affect their adherence.

AUTHORS' CONCLUSIONS

Improving short-term adherence is relatively successful with a variety of simple interventions. Current methods of improving adherence for chronic health problems are mostly complex and not very effective, so that the full benefits of treatment cannot be realized. High priority should be given to fundamental and applied research concerning innovations to assist patients to follow medication prescriptions for long-term medical disorders.

Quality of life outcomes of risperidone, olanzapine, and typical antipsychotics among schizophrenia patients treated in routine clinical practice: a naturalistic comparative study

Findings in previous studies investigating the beneficial effect of risperidone and olanzapine versus typical antipsychotics on quality of life (QOL) are controversial since they did not adjust for various factors contributing to QOL. To test this assumption in a naturalistic cross-sectional design, we evaluated general and domain-specific QOL scores for baseline data of schizophrenia outpatients stabilized on atypical (N = 78, risperidone or olanzapine) and typical (N = 55) agents. Self-report and observer-rated QOL outcomes of both risperidone and olanzapine with typical antipsychotic therapy were compared across demographic, illness-related, and treatment-related factors using analysis of variance, multivariate analysis of variance, and correlation analysis. No significant differences were found in QOL outcomes of risperidone-treated and olanzapine-treated patients. Both self-report and rater-observed QOL measures indicated superiority of atypical over typical antipsychotic agents after adjusting for daily doses, duration of treatment, subjective tolerability, and adjuvant antidepressants. Lower daily doses and longer antipsychotic treatment were associated with better QOL. Self-report and observer-rated QOL scores correlated positively (r = 0.64, P < 0.001). Gender, marital status, age, education, living arrangement and employment status, age of onset, illness duration, symptom severity, emotional distress, subtypes of schizophrenia, and side effects did not affect QOL outcomes in either group. Risperidone and olanzapine revealed an advantage over typical agents in terms of QOL. Findings suggest that when calculating the beneficial effects of atypical antipsychotic therapy on QOL outcomes, daily doses, duration of treatment, and subjective tolerability may be intervening variables and should be adjusted accordingly to clearly appreciate benefits of atypical antipsychotics.

Association study of serotonin 1B receptor (A-161T) genetic polymorphism and suicidal behaviors and response to fluoxetine in major depressive disorder

Serotonin 1B receptors (5-HT1B) are autoreceptors involved in the local inhibitory control of serotonin release, and have been suggested to play a role in the pathogenesis of major depressive disorder (MDD) and the antidepressant effects of the selective serotonin reuptake inhibitors in patients. We genotyped the 5-HT1B A-161T polymorphism in 160 patients with MDD and 160 normal controls. We then tested the hypothesis that the allelic variant, A-161T, of the 5-HT1B gene confers susceptibility to MDD or is associated with suicide attempt. We also examined the association of this polymorphism with therapeutic response in 116 of the MDD patients who received fluoxetine treatment for 4 weeks. No significant difference was found in the A-161T genetic polymorphism between MDD patients and controls. The genotype distribution between patients with and without suicide attempt, or between fluoxetine treatment responders and nonresponders were also similar. Our findings suggest that 5-HT1B A-161T genetic polymorphism does not play a major role in the susceptibility to MDD, nor is it related to suicidal attempt or the therapeutic response to fluoxetine in MDD.