You have probably heard all of these, usually from someone very sure of them. Guess before you turn each card — myth, evidence, or a bit of both — and nothing you guess is stored anywhere.
You have probably heard
A dopamine detox resets your brain’s pleasure chemical.
The claim
Myth.
You cannot drain, fast, or reset dopamine, and dopamine is not the pleasure chemical of popular telling — it tracks wanting, and the gap between what you expected and what you got.
The Ledger’s grade for “Dopamine detox”, as marketed
OutcomeD · TheoreticalMechanismMisattributed
You have probably heard
Exercise lifts your mood because of the endorphin rush.
The claim
A bit of both.
The single endorphin rush of popular telling is not what the evidence describes.
The Ledger’s grade for Structured exercise
OutcomeA · StrongMechanismPlausible
You have probably heard
Quit social media and you will feel better.
The claim
A bit of both.
The trial evidence is genuinely mixed: some studies find small wellbeing gains from cutting back, others find nothing.
The Ledger’s grade for Reducing or structuring social-media use
OutcomeC · PreliminaryMechanismSpeculative
You have probably heard
An afternoon coffee is out of your system by bedtime.
The claim
Myth.
Caffeine’s half-life — the time the body takes to clear half of it — runs to roughly five hours, and it blocks adenosine, the chemical that builds the pressure to sleep, so an afternoon cup is still present at bedtime and still degrading the sleep that carries the mood effect.
The Ledger’s grade for Cutting late-day caffeine
OutcomeB · ModerateMechanismEstablished
You have probably heard
Tryptophan-rich foods boost your serotonin and lift your mood.
The claim
Myth.
Tryptophan competes with other amino acids from the same meal for the same doorway into the brain, so the chain from mood food to serotonin to happiness breaks at its first link.
The Ledger’s grade for “Serotonin foods”
OutcomeD · TheoreticalMechanismMisattributed
You have probably heard
You have to feel motivated before you can get going.
The claim
Myth.
Behavioural activation does the reverse: scheduling and then doing something that matters to you, before the motivation to do it arrives.
The Ledger’s grade for Behavioural activation
OutcomeA · StrongMechanismPlausible
You have probably heard
Meditation is the best thing you can do for anxiety.
The claim
A bit of both.
Real reductions in anxiety and depressive symptoms, of small-to-moderate size, which shrink substantially when compared against an active alternative rather than a waiting list.
The Ledger’s grade for Mindfulness meditation
OutcomeB · ModerateMechanismPlausible
You have probably heard
Losing sleep makes your mood worse.
The claim
Evidence.
Short or broken sleep degrades mood; improving sleep improves it.
The Ledger’s grade for Sufficient, regular sleep
OutcomeA · StrongMechanismPlausible
You have probably heard
Writing about what upset you always makes you feel better.
The claim
Myth.
Across the literature the benefits are inconsistent and depend heavily on context.
The Ledger’s grade for Expressive writing
OutcomeC · PreliminaryMechanismSpeculative
You have probably heard
Nature lifts your mood because of the greenery itself.
The claim
A bit of both.
Attention restoration and stress reduction are the usual accounts, and both are hard to separate from the exercise, daylight and company that tend to arrive with a walk outdoors.
The Ledger’s grade for Time in nature
OutcomeB · ModerateMechanismPlausible
You have probably heard
People with close connections tend to have better moods.
The claim
Evidence.
Among the strongest and most consistent links in this library, and almost entirely an association.
The Ledger’s grade for Social connection
OutcomeA · StrongMechanismPlausible