Dose-dependent augmentation effect of bromocriptine in a case with refractory depression

Aripiprazole in the treatment of depressive and anxiety disorders: a review of current evidence

Despite the availability of different classes of drugs for the treatment of depressive and anxiety disorders, there are a number of clinically significant unmet needs, such as a high prevalence of treatment resistance, partial response, subsyndromal symptomatology, recurrence and relapse. With the approval of atypical antipsychotics, which are associated with a lower adverse effect burden than typical antipsychotics, consideration of their off-label use for the treatment of affective disorders and various other psychiatric disorders has become a viable option. However, consideration should be given to the US FDA black box warning indicating that atypical antipsychotics may increase mortality risk, particularly in the elderly population with dementia-related psychosis. There has been much conjecture about the utility of these atypical drugs to facilitate traditional antidepressant therapy, either in combination (from the initiation of therapy) or as adjunctive therapy (in the case of partial/incomplete response). Nevertheless, at present, available evidence from randomized, placebo-controlled trials is sparse, and a formal risk/benefit assessment of the use of these agents in a nonpsychotic patient population is not yet possible. As a representative agent from the atypical antipsychotic class with a novel mechanism of action and a relatively low adverse effect burden, aripiprazole represents an interesting potential treatment for depressive and anxiety disorders. In this review, we focus on the rationale for the use of aripiprazole in these disorders. Preclinical data suggests that aripiprazole has a number of possible mechanisms of action that may be important in the treatment of depressive and anxiety disorders. Such mechanisms include aripiprazole action at serotonin (5-HT) receptors as a 5-HT1A partial receptor agonist, a 5-HT2C partial receptor agonist and a 5-HT2A receptor antagonist. Aripiprazole also acts as a dopamine D2 partial receptor agonist, and has a possible action at adrenergic receptors. Furthermore, aripiprazole may have possible neuroprotective effects. Clinical studies demonstrate that aripiprazole may be useful in the treatment of bipolar depression, major depressive disorder, treatment-resistant depression and possibly anxiety disorders. Clinical data also suggest that aripiprazole may have a lower adverse effect burden than the other atypical drugs. Future research may confirm the potential utility of aripiprazole in the treatment of depressive and anxiety disorders.

Association of the COMT val158met variant with antidepressant treatment response in major depression

In several previous biochemical, pharmacological, and genetic studies, the catechol-O-methyltransferase (COMT) has been suggested to be involved in the pathogenesis as well as the pharmacological treatment of affective disorders. In the present study, 256 patients with major depression (DSM-IV) of Caucasian descent were genotyped for the functional COMT val158met polymorphism and characterized for clinical response to antidepressive pharmacological treatment as measured by intra-individual changes of Hamilton Depression (HAM-D-21) scores over 6 weeks. The COMT 158val/val genotype conferred a significant risk of worse response after 4-6 weeks of antidepressant treatment in patients with major depression (week 4: p=0.003; week 5: p<0.0001; week 6: p<0.0001) after Bonferroni correction for multiple comparisons. The present results strongly point toward a negative influence of the higher activity COMT 158val/val genotype on antidepressant treatment response during the first 6 weeks of pharmacological treatment in major depression, possibly conferred by consecutively decreased dopamine availability. This finding suggests a potentially beneficial effect of an antidepressive add-on therapy with substances increasing dopamine availability individually tailored according to COMT val158met genotype.

Mirtazapine monotherapy versus combination therapy with mirtazapine and aripiprazole in depressed patients without psychotic features: a 4-week open-label parallel-group study

BACKGROUND

There is preliminary evidence that the atypical antipsychotic aripiprazole, which is a partial agonist at D(2) and 5-HT(1A) receptors and a potent antagonist at 5-HT(2A) receptors, may be useful as an augmentation strategy in treatment-resistant depression.

METHOD

In this 4-week open-label non-randomized parallel-group study, the safety and efficacy of aripiprazole as add-on treatment strategy in patients suffering from non-delusional depression was investigated. Forty drug-free depressed inpatients without psychotic symptoms (13 men, 27 women), suffering from a major depressive episode or bipolar disorder, depressive state (DSM-IV criteria), were included in the study. The patients were treated either with mirtazapine monotherapy (45 mg/day) or combination therapy (mirtazapine 45 mg/day plus aripiprazole 15 mg/day) for 4 weeks. Safety and efficacy were assessed weekly using the Hamilton Depression Rating Scale, the Simpson-Angus Scale and the Barnes Akathisia Scale.

RESULTS

Mirtazapine monotherapy and combined treatment with mirtazapine and aripiprazole showed comparable antidepressant effects as assessed at the endpoint of the study period. However, additional administration of aripiprazole accelerated the onset of antidepressant action in patients suffering from treatment-resistant depression. Additive use of aripiprazole reduced the mirtazapine-induced increase in the body mass index. Moreover, mirtazapine had favourable effects on aripiprazole-induced akathisia. No other extrapyramidal side effects were seen in the combination therapy group.

CONCLUSION

Combined therapy with mirtazapine and aripiprazole is a safe and well-tolerated treatment option which may be useful especially in treatment-resistant depression. Double-blind controlled studies are needed to further explore the efficacy and safety of aripiprazole in depressed patients.

Remarkable Effect of Selegiline (L-Deprenyl), a Selective Monoamine Oxidase Type-B Inhibitor, in a Patient With Severe Refractory Depression

A 34-year-old man presented with severe refractory depression. He had failed to respond to various antidepressants, augmentation therapy with lithium carbonate, and modified electroconvulsive therapy. Switching from amoxapine 150 mg/day to selegiline 7.5 mg/day, a selective monoamine oxidase type-B inhibitor, produced a dramatic reduction in hypobulia and lassitude, leading to a complete remission of all depressive symptoms. The patient reverted to his former position at work after an interval of approximately 3 years. Although the biologic basis of the antidepressant effect of selegiline in this patient is unknown, it is suggested that the enhancement of dopaminergic neurotransmission or elevation of brain-derived neurotrophic factor levels in the brain by administration of selegiline is involved in the recovery of this patient from severe refractory depression. This report indicates the antidepressant effect of selegiline in a refractory depressed patient.

Is dopamine a limiting factor of the antidepressant-like effect in the mouse forced swimming test?

To study the role of dopamine (DA) in antidepressant-like effect in the forced swimming test (FST), the relationship between the magnitude of the antidepressant-like effect of drugs [citalopram, fluoxetine, paroxetine (selective serotonin reuptake inhibitors), desipramine (tricyclic antidepressant), maprotiline (tetracyclic antidepressant), bupropion (DA reuptake inhibitor), and tranylcypromine (inhibitor of monoamine oxidase)] and the corresponding concentration of DA in the whole brain of mice was investigated. A trend for an inversely proportional linear relationship [(magnitude of the antidepressant-like effect) = -0.0145 x (concentration of DA in the whole brain) +34.773 (r = 0.276)] was observed between the magnitude of the antidepressant-like effect and the concentrations of DA in the whole brain, but this correlation was not significant. This result suggests that the high concentration of DA in the whole brain could be a limiting factor for the antidepressant-like effect of antidepressants such as tranylcypromine and seems to play a minor role in the antidepressant-like activity of another antidepressant such as bupropion in the FST.

Dopamine, depression and antidepressants

Abstract The relationship between depression and dopamine deficiency in the mesolimbic pathway has been hypothesized for many years. The experimental studies with animal models of depression and the human studies implicate the role of the dopamine system in depression. Not only do dopaminergic receptor agonists, but also antagonists such as olanzapine exhibit antidepressant effects associated with standard antidepressants in patients with treatment-resistant depression. This paradoxical result suggests that further investigations are necessary to understand the role played by dopamine in depression.

Bromocriptine augmentation therapy in a patient with Cotard's syndrome

A 72-year-old female with bipolar I disorder developed Cotard's syndrome, i.e., various delusions of negation accompanied by severe depressive symptoms. She responded neither to the combination of antipsychotic drug and antidepressant nor to the lithium augmentation therapy. However, the delusions and depressive symptoms improved dramatically after the addition of bromocriptine 2.5-5 mg/day to the combination of clomipramine and lithium. This report suggests that bromocriptine augmentation therapy might be effective at least for some patients with Cotard's syndrome in mood disorders.

Amantadine as augmentation therapy in the management of treatment-resistant depression

Treatment-resistant depression is an important clinical problem presenting a major challenge to clinical psychiatry. While several strategies have been attempted, including medication switch, antidepressant polypharmacy and various augmentative regimens, success remains limited. Amantadine (AMN), an agent traditionally used in the treatment and prophylaxis of influenza, is now known to exhibit prominent effects at the level of dopaminergic, monoamine oxidase and N-methyl-D-aspartate systems. The present reports on the efficacy of AMN as augmentation to standard antidepressant treatment in patients with treatment-resistant depression. Eight patients with treatment-resistant depression consented to receive AMN, titrated up to a dose of 300 mg, over a period of 4 weeks in a non-blinded fashion. Improvement in both depression and anxiety scores were observed from week 1, with patients exhibiting improvement of depressive scores of up to 49% by study completion. Females appeared to exhibit a stronger response, and within a shorter period of time. Side-effects reported included dry mouth and sedation. AMN appears to demonstrate efficacy as a safe and effective augmentative agent in treatment-resistant depression. Further studies are clearly mandated to test these preliminary observations in a double-blinded manner.