Excited to finally have this one out :) This would not have been possible without the great mentorship of @nbkroemer.bsky.social all stages of the process! Work w/ @akuehnel.bsky.social and many more!

(10/10) Ghrelin, a stomach-derived hormone that increases with fasting, was associated with greater wanting and liking across reward phases.

And with higher fasting levels of ghrelin, individuals wanted food reward more independently of liking!

(9/10) We found that anhedonia - rather than depression per se - was strongly associated with altered glycemic control.

(8/10) We also looked at metabolic signals.
Why? Depression is often comorbid with diabetes, shows ⬆️ or ⬇️ in appetite, and evidence is accumulating that metabolic hormones can modulate reward responses.

(7/10) Most interestingly, the desire increased again as soon as the rewards were available - that is, even before they were consumed. This may open up new perspectives for therapeutic approaches: promoting positive expectations or increasing the immediate availability of rewarding activities?

(6/10) 🌶️ Both, lower wanting during anticipation + greater increases in wanting were associated with a questionnaire of anhedonia (SHAPS) that aims to measure hedonic capacity or consummatory pleasure - we show this does not hold up well in behavioral tests!

(5/10) Interestingly, once patients with depression smelled and later tasted the snacks, they did not differ anymore from controls, because they relatively increased (!) their wanting ratings with consummation compared to controls!

(4/10) Against a consummatory pleasure deficit in depression:
🚫 No differences in liking (during any phase)
🚫 No differences during consummation (for any ratings)
Instead:
⏩ reduced wanting during anticipation of distal food rewards in depression

(3/10) We combined clinical, behavioral and metabolic assessments in participants with major depressive disorder & healthy controls, N = 103.
Using a taste test with repeated ratings of wanting and liking, we could gradually move from reward anticipation to consummation.

(2/10) While there has been work on incorporating different reward facets in anhedonia (e.g., Treadway & Zald, 2011; Husain & Roiser, 2018), the canonical notion of anhedonia being a consummatory deficit holds strong in the literature!

(1/10) The seemingly simple distinction of „Do I want a cookie?“ or „Do I like the cookie once I eat it?“ is not a trivial question when we think about understanding reward deficits, such as in mental health disorders.

Stimulants helped children with ADHD or poor sleep (ABCD n=11k) with cognitive tasks. They counter the effects of fatigue and elevate the perceived salience of goal-oriented actions, facilitating boring tasks without directly affecting capacity to pay attention. Illustration by @sonhita.bsky.social