Reserpine augmentation of desipramine in refractory depression: clinical and neurobiological effects

Augmentative Pharmacological Strategies in Treatment-Resistant Major Depression: A Comprehensive Review

Treatment resistant depression (TRD) is associated with poor outcomes, but a consensus is lacking in the literature regarding which compound represents the best pharmacological augmentation strategy to antidepressants (AD). In the present review, we identify the available literature regarding the pharmacological augmentation to AD in TRD. Research in the main psychiatric databases was performed (PubMed, ISI Web of Knowledge, PsychInfo). Only original articles in English with the main topic being pharmacological augmentation in TRD and presenting a precise definition of TRD were included. Aripiprazole and lithium were the most investigated molecules, and aripiprazole presented the strongest evidence of efficacy. Moreover, olanzapine, quetiapine, cariprazine, risperidone, and ziprasidone showed positive results but to a lesser extent. Brexpiprazole and intranasal esketamine need further study in real-world practice. Intravenous ketamine presented an evincible AD effect in the short-term. The efficacy of adjunctive ADs, antiepileptic drugs, psychostimulants, pramipexole, ropinirole, acetyl-salicylic acid, metyrapone, reserpine, testosterone, T3/T4, naltrexone, SAMe, and zinc cannot be precisely estimated in light of the limited available data. Studies on lamotrigine and pindolol reported negative results. According to our results, aripiprazole and lithium may be considered by clinicians as potential effective augmentative strategies in TRD, although the data regarding lithium are somewhat controversial. Reliable conclusions about the other molecules cannot be drawn. Further controlled comparative studies, standardized in terms of design, doses, and duration of the augmentative treatments, are needed to formulate definitive conclusions.

Antidepressant-like effects of psoralidin isolated from the seeds of Psoralea Corylifolia in the forced swimming test in mice

The antidepressant-like effects of psoralidin isolated from the seeds of Psoralea corylifolia were investigated in the forced swimming test (FST) in ICR strain of male mice. Psoralidin significantly decreased immobility time and increased swimming behavior without altering climbing behavior in the mouse FST after oral administration for 1 h or 3 consecutive days. Psoralidin did not affect locomotor activity in the open-field test. After a 3-day treatment, psoralidin significantly increased 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) levels in various brain regions, as well as, changed dopamine (DA) levels in striatum in mice exposed to FST. Psoralidin also ameliorated the elevations in serum corticotropin-releasing factor (CRF), adrenal corticotropin-releasing hormone (ACTH) and corticosterone concentrations induced by swimming stress in mice. These results suggested that psoralidin possessed potent antidepressant-like properties that were mediated via the monoamine neurotransmitter and the hypothalamic-pituitary-adrenal (HPA) axis systems.

Neuropsychiatric consequences of cardiovascular medications

The use of cardiovascular medications can have a variety of neuropsychiatric consequences. Many cardiovascular agents cause higher rates of fatigue and sedation than placebo, and case reports of medication-induced mood syndromes, psychosis, and cognitive disturbances exist for many cardiovascular drugs. Depression has been associated with β-blockers, methyldopa, and reserpine, but more recent syntheses of the data have suggested that these associations are much weaker than originally believed. Though low cholesterol levels have been associated with depression and suicide, lipid-lowering agents have not been associated with these adverse effects. Finally, cardiovascular medications may have beneficial neuropsychiatric consequences; for example, the use of clonidine in patients with attention deficit-hyperactivity disorder, the use of prazosin for patients with post-traumatic stress disorder, and the use of propranolol for performance anxiety and akathisia.

Potentiation strategies for treatment-resistant depression

OBJECTIVE

To review the pharmacological basis of antidepressant potentiation in combination therapy and the clinical evidence for its efficacy.

METHOD

Literature searches were undertaken and the results reviewed.

RESULTS

Treatment-resistant depression is common (15-30%). Various strategies exist for dealing with resistant depression, including pharmacological potentiation, i.e. adding a treatment that itself does not have antidepressant actions but that enhances the efficacy of the original treatment. Lithium, triiodothyronine (T3) and buspirone are the best studied potentiating drugs, although other options include pindolol, dopaminergic agents, second-generation antipsychotics, psychostimulants, hormones and anticonvulsants.

CONCLUSION

Several pharmacological potentiation strategies exist. Whilst good evidence exists for lithium combined with antidepressants, although good results have also been reported with augmentation strategies involving T3 or buspirone.

Double-blind study of high-dose fluoxetine versus lithium or desipramine augmentation of fluoxetine in partial responders and nonresponders to fluoxetine

In a previous study, of 41 depressed patients who had not responded to fluoxetine 20 mg/day, 53% were treated with high-dose fluoxetine (40-60 mg/ day) and responded (i.e., their 17-item Hamilton Rating Scale for Depression [HAM-D-17] score was <7) versus 29% and 25% of patients treated with fluoxetine plus lithium (300-600 mg/day) or fluoxetine plus desipramine (25-50 mg/day), respectively. We wanted to assess whether these findings could be replicated in a larger sample of depressed outpatients. We identified 101 outpatients with major depressive disorder (52 men and 49 women; mean age, 41.6 + 10.6 years) who were either partial responders (n = 49) or nonresponders (n = 52) to 8 weeks of treatment with fluoxetine 20 mg/ day. These patients were randomized to 4 weeks of double-blind treatment with high-dose fluoxetine (40-60 mg/day), fluoxetine plus lithium (300-600 mg/day), or fluoxetine plus desipramine (25-50 mg/day). In the overall group of patients (N = 101), there was no significant difference in response rates across the three treatment groups (high-dose fluoxetine, 42.4%; fluoxetine plus desipramine, 29.4%; fluoxetine plus lithium, 23.5%). Dropout rates were also comparable, ranging from 9.1% (high-dose fluoxetine) to 14.7% (fluoxetine plus desipramine and fluoxetine plus lithium). There were also no significant differences in response rates across the three treatment groups among partial responders (high-dose fluoxetine, 50.0%; fluoxetine plus desipramine, 33.3%; fluoxetine plus lithium, 33.3%) and nonresponders (high-dose fluoxetine, 35.3%; fluoxetine plus desipramine, 26.3%; fluoxetine plus lithium, 12.5%). At the end of the study, the mean lithium level was 0.37 + 0.15 mEq/L (n = 27; range, 0.1-0.8 mEq/L) among lithium-treated patients, and the mean desipramine level was 104.7 + 58.8 ng/mL (n = 22; range, 25-257 ng/mL). There were no significant relationships between lithium or desipramine blood levels and degree of improvement (as measured by the change in HAM-D-17 score). We found no significant differences in efficacy among these three treatment strategies among patients who had failed to respond adequately to 8 weeks of treatment with fluoxetine 20 mg/day, although the high-fluoxetine group was associated with nonsignificantly higher response rates in both partial responders and nonresponders.

Effects of chronic antidepressant drug administration and electroconvulsive shock on locus coeruleus electrophysiologic activity

BACKGROUND

The locus coeruleus (LC) is the major noradrenergic cell body group in the brain. Although previous studies have examined changes in electrophysiologic activity of LC neurons produced by antidepressant drugs, only a small number have examined changes that occur with chronic drug administration, which is the therapeutically effective regimen, and only one group of investigators has assessed effects on activated (or "burst") firing of LC neurons under such treatment conditions. The present study assessed changes produced in rats by effective antidepressant treatments-several drugs given chronically (two tricyclic antidepressants, two selective serotonin reuptake inhibitors, and a monoamine oxidase inhibitor) as well as a series of electroconvulsive shocks (ECSs)-in single-unit electrophysiologic activity of LC neurons, measuring effects on spontaneous depolarization rate and also on sensory-evoked burst firing.

METHODS

Drugs were administered via osmotic minipumps for either 14 or 30 days; ECSs were administered five times, with a 72-hour interval between each administration. Electrophysiologic recording of LC activity took place under halothane anesthesia on the last day of drug treatment or following a delay of 1 or 5 days after the final ECS.

RESULTS

A common effect of all drugs tested and ECS treatment was to decrease LC spontaneous and sensory-evoked burst firing.

CONCLUSIONS

The clinical efficacy of antidepressant medication and ECS may be mediated, in part, through reduction of LC neural activity. The findings reported here are consistent with recent indications that LC neurons are hyperactive in depressed individuals and with suggestions that some behavioral changes seen in depression can arise from consequences of rapidly depolarizing LC terminals, such as release of peptides.

Predicting outcome of lithium added to antidepressants in resistant depression

This study was conducted to assess the predictive value of different variables including the response to dexamethasone suppression test (DST), in 105 patients with resistant depression after the addition of lithium (600 to 800 mg/day) for 4 weeks to antidepressant medication. Clinical remission was observed in 57 patients and no improvement in 48. A dramatic and rapid relief of depression occurred in 12 patients. Variables with significant or marginally significant differences between responders and non-responders were included in a stepwise logistic regression model. Weight loss (P = 0.0013) and depressive psychomotor activity (P = 0.045) in the Newcastle diagnostic index (NDI) scale, and overall score of the Hamilton Rating Scale for Depression (HRSD) before adding the lithium (P = 0.0039) were significantly associated with clinical remission. The difference in post-DST cortisol plasma levels between both groups was marginally significant. The logistic equation resulted in a sensitivity of 78% and a specificity of 65% and total correct classification of the lithium-added response of 72%. The clinical profile of patients who improve with the addition of lithium may include significant weight loss, psychomotor retardation and possibly, poor control of cortisol secretion. Partial remission before adding lithium as well as endogenomorphic traits according to NDI may also be considered additional criteria for response.

Novel strategies for treatment-resistant depression

This article describes a highly selective constellation of the more unique strategies for managing the treatment-resistant patient. In light of the often-devastating toll that treatment-resistant depression takes on an individual's life, it behooves us to continue the search for more effective strategies for those patients that fail more traditional interventions. As each successive move down the treatment algorithm flowchart becomes necessary, the risk/benefit ratio may shift toward less well-substantiated, but still biologically informed, strategies. Although some of the more unusual treatments described in this article represent minimally charted territories, the more promising techniques are deserving of further careful exploration.

Treatment-resistant depression: a critique of current approaches

The clinical and research literature on "treatment-resistant depression" is sampled and reviewed. Major conceptual and methodological inadequacies are identified in this literature. The main conceptual problem consists of a confounding of syndrome description with clinicians' treatment-outcome expectations. Methodological problems include: (a) the failure to adequately conceptualise and/or specifically define treatments; (b) the extreme variety of treatments evaluated in the absence of methodological controls; (c) inadequate sampling procedures; (d) the heterogeneity of the patient samples; (e) the bias in favour of reporting positive results; (f) the misrepresentation of outcome in published reports; and (g) the neglect of considering spontaneous remission as a viable alternative explanation. It is recommended that research attention be refocused on defining the characteristics of the depressed person who does not respond to standard anti-depressant therapies, as a precursor to identifying a specific therapy.

Lithium augmentation in antidepressant-resistant patients. A quantitative analysis

A quantitative analysis was used to examine the efficacy of lithium augmentation in the acute treatment of depressed patients resistant to a standard trial of an antidepressant. Effect sizes were measured by the odds ratio using the Mantel-Haenszel method. Only controlled trials were included in order to minimise bias in method. A highly statistically significant effect for lithium augmentation was found, the pooled odds ratio being 0.146 and its 95% confidence interval 0.05-0.44 (i.e. the odds of remaining ill are reduced by between 56% and 95% with the use of lithium treatment). While these results support the case for lithium augmentation in treatment-resistant depression, there remains considerable uncertainty over the duration of treatment necessary to see and sustain the treatment response.

After lithium augmentation: a retrospective follow-up of patients with antidepressant-refractory depression

There have been no systematic follow-up studies of depressed patients with documented refractoriness to antidepressants treated with lithium augmentation. To assess their longitudinal course, 66 (88%) of an original cohort of 75 such patients were followed in a retrospective, naturalistic design for 29.0 +/- SD 15.3 months. At follow-up, 29% had poor, 23% fair, and 48% good outcomes. An acute marked positive response to lithium augmentation predicted a good subsequent course. Acute partial and non-responders had a less benign outcome despite subsequent treatments. These findings indicate that outcomes of patients with documented refractory depression are heterogeneous. There is a suggestion that an acute marked response to lithium augmentation is sustained regardless of the duration of taking lithium, but this must be regarded as speculative.

Proposals for the mechanism of action of convulsive therapy: a synthesis

The convulsive therapies have been powerful additions to somatic treatment in psychiatry and have enjoyed widespread application for the benefit of many. A number of theories have been advanced in efforts to account for therapeutic efficacy but none has been comprehensive. These theories can be distinguished by whether they posit a central therapeutic role for stimulation, inhibition, psychological effects, or mixed processes induced by treatment. After critically reviewing extant theories, we propose a model for the effects of the convulsive therapies: Convulsive therapy is essentially nonspecific; "nonphysiological" depolarizations are distinctly important for the restoration of aberrant intravesicular transmitter ratios with resultant therapeusis. We present this model as a working hypothesis that may contribute to the guidance of research in the mechanism of action of convulsive treatment and offer several testable hypotheses in this regard.

Reserpinization enhances electroconvulsive treatment effects on cortical alpha 1-adrenoceptors

Repeated electroconvulsion shock (ECS) for 7 days given to mildly reserpinized rats strongly elevated the density of [3H]prazosin-labelled alpha 1-adrenoceptors and depressed the EC50 for norepinephrine-stimulated inositol phosphate accumulation, while the effects of either treatment given alone were small or negligible. Alterations in alpha 1-adrenoceptor activity caused by ECS could possibly be a function of receptor sensitivity during drug treatment.