There might also be adverse effects on one's sleep quality, even if they only drink it in the morning:

> In fact, none of the sleep researchers or experts on circadian rhythms I interviewed for this story use caffeine.

https://www.theguardian.com/food/2021/jul/06/caffeine-coffee...

I'll +1 that, and I'm one of those people but only if I'm already in a poor mental state. When I have something to feel anxious about (e.g, health concerns), then coffee consistently makes me feel more anxious.

Although, it doesn't make me feel anxious on most days, it's really only if I already have a prior reason, it just exacerbates it.

The journal article actually touches on that:

>In CD participants, indoles such as indole-3-propionic acid (IPA) and indole-3-carboxyaldehyde (ICA) and the neurotransmitter γ-aminobutyric acid (GABA) were significantly decreased.

GABA is an anti-anxiety neurotransmitter, it's what benzodiazepines mimic.

Caffeine-induced anxiety disorder is a real thing.