The problem of weight gain while taking antidepressants is a big and much discussed problem. There are many internet forums where people affected report it and hope for advice and help from “fellow sufferers”. With some of the preparations, weight gain is known to be a side effect, but with others, such a change does not occur or rather the opposite is true for such preparations – weight loss.
Tri- and tetracyclic antidepressants
In the case of the tri- and tetracyclic antidepressants, the inhibition of certain receptors leads to an increase in appetite and thus automatically to weight gain if this is not counteracted. This is a very common side effect, especially with amitripytilin, clomipramine, doxepin, imipramine and trimipramine.
The alpha-2 antagonists also increase appetite and body weight. This is observed more frequently with mirtazapine than with Mianserin.
SSRI and SNRI
The selective serotonin reuptake inhibitors (SSRI) and serotonin and noradernalin reuptake inhibitors (SNRI), on the other hand, are more likely to result in weight loss, as they lead to loss of appetite and thus weight reduction through increased activation of certain central receptors. Fluoxetine is a selective serotonin reuptake inhibitor (SSRI). This active ingredient leads to an increase in serotonin levels in the central nervous system, which has a mood-lifting effect.
Compared to the tricyclic antidepressants used for a long time, SSRIs are characterised by a greater therapeutic breadth (lower risk of massive side effects in the event of overdose) and a smaller spectrum of side effects. Common side effects are sexual dysfunction (loss of libido) and gastrointestinal complaints (nausea, vomiting). At the beginning of the therapy an increased anxiety sensation can also occur due to the increased serotonin levels.
Like fluoxetine, citalopram belongs to the group of selective serotonin reuptake inhibitors (SSRIs). The mood-lifting effect of the drug is due to increased serotonin levels in the central nervous system. Like fluoxetine, citalopram is characterised by a wider therapeutic range and a narrower spectrum of side effects compared to tricyclic antidepressants. Instead, sexual dysfunction (loss of libido, erectile dysfunction) and gastrointestinal problems (nausea, vomiting) are common.
Valdoxan is a new generation antidepressant with the active ingredient agomelatine. Via mechanisms that have not yet been fully elucidated, Valdoxan leads to increased norepinephrine and dopamine levels in the central nervous system. At the same time, an improvement in deep sleep phases leads to a better quality of sleep. The typical side effects of antidepressants (loss of libido, erectile dysfunction, weight gain) rarely occur during treatment with Valdoxan. Instead, they cause severe damage to the liver, which is why Valdoxan is not allowed in patients with impaired liver function.