I’ll call the person in question A.

A has a borderline personality disorder diagnosis, has been on various medications since adolescence, changed psychiatrists, and now they’re currently prescribed 150mg sertraline (I think, I don’t have 100% dose certainty for this med, but pretty sure), 150mg bupropion, 150mg venlafaxine, and 10mg vortioxetine.

Based on my understanding, we have:

An SSRI (sertraline), boosting serotonin and I think also has a small effect on dopamine

An NDRI (bupropion), with primary action on noradrenaline and some dopamine action

An SNRI (venlafaxine), with serotonin and noradrenaline action

And a multimodal antidepressant, vortioxetine, which should also target and modulate serotonin and a series of other neurotransmitter systems (noradrenaline, acetylcholine, glutamate, dopamine… from what I read in Stahl’s prescriber’s guide, I’m not too familiar with this drug)

Although most have somewhat different mechanisms of action, it seems to me that there’s a lot of redundancy and overlap, specifically with serotonin and noradrenaline, as well as dopamine. So my question is, why would a psychiatrist layer meds with such overlapping mechanisms? Are there situations where this cocktail makes sense, or is it overkill?

I don’t have a full history of A’s medications and their reaction to them, and the psychiatrist probably has more knowledge about the case, but it still seems unusual to me to prescribe concomitantly such similar meds. Is this really fine tuning, or more of a “shotgun” approach? Since I know that monotherapies are generally preferred where possible.

They’ve been on this combination for 3-4 months now.

In terms of efficacy of the combination, it seems to be working generally, they’re more stable in general, but there are still some side effects like sleep irregularities, excessive sweating, and possibly some others that I’m not aware of, and I’m not sure about other potential physiological and metabolic side effects.

I’d love to learn more about the theory and rationale behind this! Thanks!