Efficacy, safety, and indications for tricyclic and newer antidepressants

Beyond the monoaminergic hypothesis: agomelatine, a new antidepressant with an innovative mechanism of action

There are many potentials for the development of more effective, better tolerated, and more rapidly acting antidepressants. As there is large prevalence of circadian dysfunction in various affective disorders, including depression, one of the approaches is the development of antidepressant drugs with melatonergic agonist properties. Agomelatine, with its melatonergic agonistic (at both MT(1) an MT(2) receptors) and 5-HT(2C) antagonistic properties, represents a new concept for the treatment of depression. The antidepressant action of agomelatine has been initially demonstrated in animal models of depression, such as the forced swim - the learned helplessness - and the chronic mild stress paradigms. Subsequent studies demonstrated that the antidepressant activity of agomelatine does not solely depend on its agonistic action at melatonergic receptors, but also on its antagonistic activity at 5-HT(2C) receptors. Agomelatine also exhibits anxiolytic properties that bear a striking resemblance to those of selective 5-HT(2C) receptor antagonists. In patients with major depressive disorder, agomelatine had efficacy at least comparable to that seen with available antidepressants. Interestingly, agomelatine demonstrated antidepressant efficacy not only in patients with a moderate depressive episode but also in a more severe depressed subpopulation of patients. The treatment effect increased with the severity of the disease. Agomelatine also rapidly regulates the sleep-wake cycle without causing sedation and improves daytime condition. Agomelatine has an excellent safety profile, is weight neutral, does not affect sexual functioning and does not cause discontinuation syndrome. Collectively, its efficacy, together with its excellent tolerability, makes agomelatine an especially promising antidepressant for the near future.

The SSRIs drug Fluoxetine, but not the noradrenergic tricyclic drug Desipramine, improves memory performance during acute major depression

Accumulating evidence suggests that noradrenergic and serotonergic drugs are equally effective in ameliorating the depressive symptoms of major depression. Major depression is associated also with memory impairments, but the comparative effects of the antidepressant drugs on memory are not clear. We previously found that serotonergic neurotransmission is of particular importance for some aspects of episodic memory. We set out to test whether treatment with the selective serotonergic drug Fluoxetine (Prozac) would be advantageous in this respect over treatment with the selective noradrenergic tricyclic antidepressant drug Desipramine (Deprexan). Seventeen patients with major depressive episode, randomly assigned for treatment with either Fluoxetine (n = 8) or Desipramine (n = 9), were assessed for their clinical situation and for memory performance at the beginning of treatment, after 3 weeks, and after 6 weeks of pharmacological treatment. We found that although clinically both drugs were equally effective, the improvement of memory performance in the Fluoxetine-treated patients was significantly greater compared with that of the Desipramine-treated patients. The results support the role of serotonin in memory. More studies in larger samples of patients are required, but it may be that in cases where memory impairment is a major symptom, it would be beneficial to consider serotonergic antidepressant drugs for treatment. Furthermore, in cases where, for various reasons, the treatment of choice is noradrenergic, it may be worthwhile to consider a supplementary serotonergic drug to improve memory deficits.

Depression in Europe: experience from the DEPRES II survey. Depression Research in European Society

Despite being one of the most prevalent psychiatric conditions in the community, depression is commonly unrecognised in clinical practice. The Depression Research in European Society (DEPRES) survey examined depression in a pan-European population (N=78463) and identified a 6-month prevalence of depression of 17%. In DEPRES II (N=1884), more than 50% of the individuals were categorised as being currently depressed, with one-third receiving antidepressant treatment. Cluster analysis grouped patients within six clearly differentiated types. Individuals with patient type 'severe depression and anxiety' (Group III), had the greatest number of symptoms and were more likely to be taking antidepressants than the other patient groups. In Group III, depression prevented individuals from undertaking normal activities for 6 weeks and prevented them from working for 1 month. The patient type making the most demands on healthcare resources are those with depression and anxiety. Prompt and effective treatment would be of benefit to all patient types, and the use of a selective serotonin reuptake inhibitor (SSRI) with activity against anxiety symptoms is an appropriate management strategy.

Managing depression and anxiety in the elderly patient

Depression in the elderly is under-recognised and under-treated, even more than in younger patients. Late-life depression is a chronic and disabling illness, but there is a common misconception that it is a normal feature of ageing. It can also be difficult to differentiate depression from coexisting anxiety and cognitive disorders. Antidepressants are as effective in acute treatment in older, as in younger, depressed adults. Maintenance antidepressant therapy also appears as effective in older patients. It may, however, be difficult to attain therapeutic levels of tricylic antidepressants (TCAs) in the elderly because of side effects. The selective serotonin re-uptake inhibitors (SSRIs) have more favourable safety and tolerability profiles, making them a suitable treatment option for older patients, who are more vulnerable to adverse effects. In selecting an SSRI for treating late-life depression, its pharmacokinetic profile and effects on coexisting illnesses that are prevalent in the elderly, such as anxiety, dementia and cardiovascular disease, also need to be considered.

Comparative efficacy and tolerability among different selective serotonin re-uptake inhibitors and venlafaxine in a naturalistic setting

The objective of this study was to compare, in a naturalistic setting, the efficacy and tolerability of currently available Selective Serotonin Reuptake Inhibitors (SSRIs) and venlafaxine in outpatients at a primary psychiatric care centre in Spain. The sample was composed of 194 patients with mood disorders (major depressive disorder or dysthymic disorder according to the DSM-TV criteria) who began treatment either with an SSRI (fluoxetine, fluvoxamine, paroxetine, sertraline, and citalopram) or with venlafaxine. Baseline severity of the mood disorder was assessed using the Hamilton Depression Rating Scale and State-Trait Anxiety Inventory, and therapeutic response was measured with the Clinical Global Impression for Therapeutic Improvement. Tolerability was assessed by recording spontaneously reported adverse experiences. There were no significant differences in the efficacy of the antidepressants under study, but there were differences in the incidence and profiles of adverse events. Fluoxetine was associated with the lowest incidence of adverse effects, in a logistical regression model, but particular events seemed to be associated with certain treatments: gastrointestinal discomfort (fluvoxamine), tremor (sertraline), dry mouth and dizziness (venlafaxine) and sweating and nervousness (citalopram). We conclude that in clinical practice there are differences in the tolerability of these antidepressants. Studies with bigger samples are needed to confirm these findings.

New aspects of diagnosis and pharmacotherapy of eating disorders

This paper points out recent diagnostic features of bulimia and anorexia nervosa and of the recently defined 'binge eating disorder'. The pharmacologic treatment approaches for these conditions will be reviewed by discussing the results of randomized controlled studies. For anorexia nervosa (AN), the outcome of pharmacotherapy has been poor, in contrast to bulimia nervosa (BN) and binge eating disorder (BED), where pharmacological treatment, primarily with antidepressants, has proved to be effective, at least in the short run. However, long-term outcome studies are still awaited. (MJ Psych Clin Pract 1997; 1: 21-35).

Do SSRIs differ in their antidepressant efficacy

Selective serotonin reuptake inhibitors (SSRIs) have been extensively studied worldwide and show at least equivalent efficacy to the tricyclic antidepressants (TCAs). Some of the SSRIs have demonstrated superior efficacy to TCAs in a number of subgroups including patients with severe depression, suicidal thoughts or depression associated with anxiety. There is currently a lack of direct comparative data between the different SSRIs, although the few studies which are available indicate overall equal efficacy. However, the pharmacodynamic and pharmacokinetic characteristics may result in different side-effects which might, in turn, lead to a characteristic pattern of use.