Sleep, mood disorders and antidepressants: the melatonergic antidepressant agomelatine offers a new strategy for treatment

Abstract

Insomnia often precedes the appearance of mood changes. While the presence of disturbed sleep prior to the onset of depressed mood is useful prognostically, the ultimate co-occurrence of these symptoms can pose a considerable challenge for pharmaceutical therapy. Most currently used antidepressants (tricyclics, monoamine oxidase inhibitors, serotonin-norepinephrine reuptake inhibitors, serotonin receptor-2 antagonist/serotonin reuptake inhibitors, selective serotonin reuptake inhibitors) are effective antidepressants but they have the disadvantage that often aggravate sleep disturbances. An ideal antidepressant should address both problems: such an antidepressant should exert a rapid onset of action both on depressive symptomatology as well on sleep problems. The recently introduced novel antidepressant agomelatine has melatonergic agonist and 5-HT2C antagonistic properties, and has been found effective in improving both depressive mood and sleep disturbances. Its mechanism of action differs from the currently used antidepressants. It thus represents a possible first line drug for treatment of mood disorders such as major depressive disorder, bipolar disorder and seasonal affective disorder. This review summarises what is known about the clinical efficacy and mechanism of action of agomelatine and compares these findings with those of currently available antidepressants.