Understanding antidepressant discontinuation syndrome (ADS) through preclinical experimental models

Antidepressant discontinuation syndrome: A state-of-the-art clinical review

Antidepressant drugs are prescribed to patients with depressive, anxiety disorders, and other conditions. Evidence about antidepressant discontinuation syndrome (ADS) and related outcomes is sparse, although potentially burdensome in some patients. The present state-of-the-art review aims to appraise the most current evidence about ADS critically. ADS has been documented for most antidepressant drugs, although most literature focuses on selective serotonin reuptake inhibitors prescribed for depression. While down-titration cannot exclude the chance of ADS, it is nonetheless warranted in the clinical setting, especially for short half-life and sedative compounds such as paroxetine. Integrative management with concurrent pharmacotherapy and psychotherapy may minimize the eventual unpleasant effects arising within the discontinuation process. In addition, patient-tailored interventions and education should be part of the discontinuation strategy. Future research must rely on broadly accepted definitions for ADS and related phenomena such as antidepressant withdrawal and shed further light on the underpinning neurobiology. Discriminating between ADS-related phenomena and relapse of depression is likewise warranted, along with a neuroscience-based nomenclature instead of a class one.

Short-course antidepressant therapy reduces discontinuation syndrome while maintaining treatment efficacy in patients with refractory functional dyspepsia: A randomized controlled trial

BACKGROUND AND OBJECTIVE

Long-course (LC) antidepressants for the treatment of disorders of gut-brain interaction, such as refractory functional dyspepsia (rFD), pose patients at risk of antidepressant discontinuation syndrome (ADS). Short-course (SC) therapy of rapid-acting antidepressant may reduce discontinuation syndromes while maintaining efficacy for dyspeptic symptoms. However, the evidence-based research is lacking. This study aims to determine whether SC therapy with antidepressants could decrease the risk of ADS with comparable treatment efficacy to LC therapy in rFD.

METHODS

This randomized clinical trial with rFD patients was conducted at a tertiary hospital in China. Participants (N = 240) were randomly allocated to receive flupentixol-melitracen (FM) plus omeprazole therapy for 2 (SC group) or 4 (LC group) weeks, respectively. Scores for Leeds Dyspepsia Questionnaire (LDQ), Generalized Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire-9 for Depression (PHQ-9) were assessed at baseline and every 2 weeks, ending at 4 weeks after treatment. ADS was assessed after drug cessation. Medication possession ratio (MPR) for FM was calculated.

RESULTS

The severity and incidence of ADS of patients in SC group were significantly lower than those in LC group (0.60 ± 0.62 vs. 1.71 ± 1.58 and 3.64 vs. 39.45%; both P < 0.0001). The MPR values for FM were significantly higher in patients of SC group than in LC group (P < 0.0001). Scores for LDQ, GAD-7 and PHQ-9 decreased in patients of both groups, and the symptom improvement in SC group was comparable to that in LC group after treatment.

CONCLUSIONS

Compared to 4-week FM therapy, the 2-week FM therapy reduces the risk of ADS with non-inferior treatment efficacy in patients with rFD.

CLINICAL TRIAL REGISTRATION

Clinical trials.gov, identifier NCT05099913.

Antidepressants Produce Persistent Gα s-Associated Signaling Changes in Lipid Rafts after Drug Withdrawal

Termination of antidepressant therapy often has negative consequences. Although symptoms of antidepressant withdrawal are widely recognized, the molecular processes that underlie them are not well characterized. We show that certain aspects of Gα _s signaling remain suppressed after antidepressant withdrawal, even after others have reverted to baseline. Antidepressant treatment causes translocation of Gα _s protein from lipid rafts to nonraft membrane regions. This results in augmented Gα _s signaling, including facilitated activation of adenylyl cyclase and increased cAMP accumulation. Using CC6 or SK-N-SH cells and a lipid raft-localized cAMP sensor, we show that Gα _s signaling is reduced in lipid rafts, even while signaling is enhanced elsewhere in the cell. These signaling changes mirror the changes in Gα _s localization observed after antidepressant treatment. Furthermore, we show that suppression of Gα _s signaling in lipid rafts persists at least 24 hours after cessation of antidepressant treatment. Gα _s localization was quantified after membrane isolation and sequential detergent extraction. We show that suppression of lipid raft Gα _s signaling persists for an extended time period after antidepressant withdrawal, whereas increased nonraft membrane Gα _s signaling reverts partially or fully upon cessation of antidepressant treatment. Translocation of Gα _s out of lipid rafts is also persistent. These events may reflect cellular adaptations to antidepressant treatment that contribute to antidepressant discontinuation syndromes and may aid in the discovery of new treatments and strategies to mitigate the symptoms of depression and antidepressant withdrawal. SIGNIFICANCE STATEMENT: This work explores, for the first time, the effects of antidepressants on Gα _s signaling after drug withdrawal. This provides novel insight into the cellular and molecular processes affected by antidepressant drugs and their persistence after discontinuation of treatment.

Adherence to psychotropic medication in completed suicide in Sweden 2006-2013: a forensic-toxicological matched case-control study

OBJECTIVE

To investigate the influence of adherence to psychotropic medications upon the risk of completed suicide by comparing person-level prescriptions and postmortem toxicological findings among complete-suicide cases and non-suicide controls in Sweden 2006-2013.

METHODS

Using national registries with full coverage on dispensed prescriptions, results of medico-legal autopsies, causes of death, and diagnoses from inpatient care, estimated continuous drug use for 30 commonly prescribed psychotropic medications was compared with forensic-toxicological findings. Subjects who had died by suicide (cases) were matched (1:2) with subjects who had died of other causes (controls) for age, sex, and year of death. Odds ratios were calculated using logistic regression to estimate the risk of completed suicide conferred by partial adherence and non-adherence to pharmacotherapy. Adjustments were made for previous inpatient care and the ratio of initiated and discontinued dispensed prescriptions, a measure of the continued need of treatment preceding death.

RESULTS

In 5294 suicide cases and 9879 non-suicide controls, after adjusting for the dispensation ratio and other covariates, partial adherence and non-adherence to antipsychotics were associated with 6.7-fold and 12.4-fold risks of completed suicide, respectively, whereas corresponding risk estimates for antidepressant treatment were not statistically significant and corresponding risk increases for incomplete adherence to antidepressant treatment were lower (1.6-fold and 1.5-fold, respectively) and lacked statistical significance.

CONCLUSION

After adjustment for the need of treatment, biochemically verified incomplete adherence to antipsychotic pharmacotherapy was associated with markedly increased risks of completed suicide.

Animal models of major depressive disorder and the implications for drug discovery and development

INTRODUCTION

Depression is a highly debilitating psychiatric disorder that affects the global population and causes severe disabilities and suicide. Depression pathogenesis remains poorly understood, and the disorder is often treatment-resistant and recurrent, necessitating the development of novel therapies, models and concepts in this field. Areas covered: Animal models are indispensable for translational biological psychiatry, and markedly advance the study of depression. Novel approaches continuously emerge that may help untangle the disorder heterogeneity and unclear categories of disease classification systems. Some of these approaches include widening the spectrum of model species used for translational research, using a broader range of test paradigms, exploring new pathogenic pathways and biomarkers, and focusing more closely on processes beyond neural cells (e.g. glial, inflammatory and metabolic deficits). Expert opinion: Dividing the core symptoms into easily translatable, evolutionarily conserved phenotypes is an effective way to reevaluate current depression modeling. Conceptually novel approaches based on the endophenotype paradigm, cross-species trait genetics and 'domain interplay concept', as well as using a wider spectrum of model organisms and target systems will enhance experimental modeling of depression and antidepressant drug discovery.