Atypical Antipsychotics and Other Therapeutic Options for Treatment of Resistant Major Depressive Disorder

Opipramol Inhibits Lipolysis in Human Adipocytes without Altering Glucose Uptake and Differently from Antipsychotic and Antidepressant Drugs with Adverse Effects on Body Weight Control

Treatment with several antipsychotic drugs exhibits a tendency to induce weight gain and diabetic complications. The proposed mechanisms by which the atypical antipsychotic drug olanzapine increases body weight include central dysregulations leading to hyperphagia and direct peripheral impairment of fat cell lipolysis. Several investigations have reproduced in vitro direct actions of antipsychotics on rodent adipocytes, cultured preadipocytes, or human adipose tissue-derived stem cells. However, to our knowledge, no such direct action has been described in human mature adipocytes. The aim of the present study was to compare in human adipocytes the putative direct alterations of lipolysis by antipsychotics (haloperidol, olanzapine, ziprazidone, risperidone), antidepressants (pargyline, phenelzine), or anxiolytics (opipramol). Lipolytic responses to the tested drugs, and to recognized lipolytic (e.g., isoprenaline) or antilipolytic agents (e.g., insulin) were determined, together with glucose transport and amine oxidase activities in abdominal subcutaneous adipocytes from individuals undergoing plastic surgery. None of the tested drugs were lipolytic. Surprisingly, only opipramol exhibited substantial antilipolytic properties in the micromolar to millimolar range. An opipramol antilipolytic effect was evident against isoprenaline-, forskolin-, or atrial natriuretic peptide-stimulated lipolysis. Opipramol did not impair insulin activation of glucose transport but inhibited monoamine oxidase (MAO) activity to the same extent as antidepressants recognized as MAO inhibitors (pargyline, harmine, or phenelzine), whereas antipsychotics were inefficient. Considering its unique properties, opipramol, which is not associated with weight gain in treated patients, is a good candidate for drug repurposing because it limits exaggerated lipolysis, prevents hydrogen peroxide release by amine oxidases in adipocytes, and is thereby of potential use to limit lipotoxicity and oxidative stress, two deleterious complications of diabetes and obesity.

Characteristics of patients with depression initiating or switching antidepressant treatment: baseline analyses of the PERFORM cohort study

BACKGROUND

Patients who require a switch in their antidepressant therapy may have different clinical profiles and treatment needs compared with patients initiating or maintaining a first-line antidepressant therapy.

METHODS

The Prospective Epidemiological Research on Functioning Outcomes Related to Major depressive disorder (MDD) (PERFORM) study was a 2-year observational cohort study in outpatients with MDD in five European countries. Enrolled patients were either initiating or undergoing the first switch to an antidepressant monotherapy. Baseline data on patients' clinical status, functioning, productivity, quality of life and medical-resource use were compared in a cross-sectional baseline analysis.

RESULTS

A total of 1402 patients were enrolled, of whom 1159 (82.7%) provided analysable baseline data. The majority (78.7%) of the analysable population were initiating antidepressant treatment and most (83.6%) were enrolled and followed up by general practitioners. Compared with patients initiating antidepressants, those switching antidepressants (21.3%) tended to have more severe depressive symptoms, greater anxiety, worse health-related quality of life, greater functional impairment, greater medical-resource use and had a different medical history. Limitations included an over-representation of switches due to lack of efficacy among patients who were switching treatment, as patients were selected based on presence of depressive symptoms.

CONCLUSIONS

Patients with MDD who are switching treatment for the first time have a different profile and different depression-associated health needs compared with those initiating treatment. Therapeutic management should therefore be adapted for patients who switch.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01427439 ; Retrospectively registered 26 August 2011.

Antidepressant therapies inhibit inflammation and microglial M1-polarization

Macrophages and their counterparts in the central nervous system, the microglia, detect and subsequently clear microbial pathogens and injured tissue. These phagocytic cells alter and adapt their phenotype depending on their prime activity, i.e., whether they participate in acute defence against pathogenic organisms ('M1'-phenotype) or in clearing damaged tissues and performing repair activities ('M2'-phenotype). Stimulation of pattern recognition receptors by viruses (vaccines), bacterial membrane components (e.g., LPS), alcohol, or long-chain saturated fatty acids promotes M1-polarization. Vaccine or LPS administration to healthy human subjects can result in sickness symptoms and low mood. Alcohol abuse and abdominal obesity are recognized as risk factors for depression. In the M1-polarized form, microglia and macrophages generate reactive oxygen and nitrogen radicals to eradicate microbial pathogens. Inadvertently, also tetrahydrobiopterin (BH4) may become oxidized. This is an irreversible reaction that generates neopterin, a recognized biomarker for depression. BH4 is a critical cofactor for the synthesis of dopamine, noradrenaline, and serotonin, and its loss could explain some of the symptoms of depression. Based on these aspects, the suppression of M1-polarization would limit the inadvertent catabolism of BH4. In the current review, we evaluate the evidence that antidepressant treatments (monoamine reuptake inhibitors, PDE4 inhibitors, lithium, valproate, agomelatine, tianeptine, electroconvulsive shock, and vagus nerve stimulation) inhibit LPS-induced microglia/macrophage M1-polarization. Consequently, we propose that supplementation with BH4 could limit the reduction in central monoamine synthesis and might represent an effective treatment for depressed mood.