It’s still real, and still physical
Depression changes sleep, appetite, stress hormones and how the brain learns from experience. A one-chemical story was too simple. Plenty is still going on in the body and brain.
01 · Not sadness
Sadness is a feeling. Depression is a state.
Sadness is usually about something, and it moves. Depression can arrive without a reason, outlast the reason it had, and flatten everything else on the way, good feelings and bad ones alike.
Sadness
Depression
Cause
About something: a loss, a letdown, a goodbye
Can arrive with no clear reason, or outlast the one it had
Shape
Comes in waves, often set off by reminders
Flat and steady, most of the day, nearly every day
Other feelings
Still there. You can laugh in the middle of grief
Turned down too. Many people feel numb, empty or irritable rather than sad
Good things
Still land, even if briefly
Stop landing. Clinicians call this anhedonia
Self-worth
Mostly intact
Erodes into guilt, worthlessness, feeling like a burden
Body
Mostly unchanged
Sleep, appetite, energy and movement shift
Time
Eases over days to weeks
Two weeks or more, and often doesn’t lift on its own
Grief can turn into depression, and the two can sit together. If the right-hand column has fit for two weeks or more, book a GP appointment.
It isn’t the opposite of happiness either.
Mood runs from sad to happy. Depression sits on a different axis: how alive things feel. That’s why someone can smile through a dinner and still be depressed, and why grief, painful as it is, usually isn’t.
AliveVitalityFlat
Grief
Sad, and still feeling and caring
A good day
Happy and engaged
A bad week
Fed up, but still yourself
A lazy Sunday
Content, low energy
The way out runs up
Depression
Low vitality, whichever way mood points
quietly sadnumbsmiling, still empty
SadMoodHappy
“The opposite of depression is not happiness, but vitality.”Andrew Solomon · TEDxMet, 2013
Pushing for happiness aims right on that map. Recovery mostly comes from moving up: interest, energy, contact and doing things that matter.
Chasing happy may not help. In a 2014 study of people who’d had depression, those who valued happiness most had more symptoms, and as a group they valued happiness more than people who’d never been depressed.
02 · The nine signs
Of nine signs doctors ask about, one is feeling down.
This is the PHQ-9, one of the most widely used depression questionnaires. Four of its nine questions are about your body. To be diagnosed you need low mood or lost interest, so depression is possible without feeling sad at all.
The nine, grouped
Feeling3
Body4
Mind2
Over the last 2 weeks, how often have you been bothered by…
03 · The serotonin story
The low-serotonin story didn’t hold up.
For decades depression was explained as a chemical imbalance: too little serotonin, topped up by a pill. It was simple and it eased stigma. When researchers pulled the evidence together, it wasn’t there.
1950sAccident
Two drugs lift mood by chance
Iproniazid, a tuberculosis drug, and imipramine, tested for other conditions, both improve mood in some patients. Both act on brain chemicals called monoamines.
1965–67Hypothesis
Reasoning backwards
If drugs that raise these chemicals help, perhaps depression is a shortage of them. Noradrenaline is proposed first, then serotonin.
1987–90sMarketing
Prozac, and “chemical imbalance”
Fluoxetine reaches the US market and the SSRI era begins. A serotonin shortage becomes the standard public explanation, much of it through advertising.
2014Side effect
The story changes how people cope
People with current or past depression who were told (via a fake test) that a chemical imbalance caused it didn’t blame themselves less. They grew more pessimistic about recovery and less confident they could manage their own mood.
Kemp, Lickel & Deacon · Behaviour Research and TherapyJul 2022Review
No consistent evidence of a shortage
An umbrella review led by Joanna Moncrieff at UCL pooled decades of work on serotonin in blood and brain fluid, its receptors and transporter, artificial depletion, and genes. It found no convincing evidence that depression is caused by low serotonin.
Moncrieff et al. · Molecular PsychiatryDec 2022Counterpoint
Some evidence of reduced release
A brain-imaging study of 17 people with depression and 20 without found a reduced capacity to release serotonin in depression. It’s a small study, and the authors said serotonin problems are unlikely to explain everything about depression.
Erritzoe et al. · Biological PsychiatryNowConsensus
Many causes, interacting
Genes, ongoing stress, loss, loneliness, trauma, poor sleep, inflammation, physical illness and some medications all contribute. Serotonin may play a part for some people. No single chemical explains depression.
What this does and doesn’t mean.
Antidepressants still help many people
All 21 antidepressants in the largest comparison beat placebo over about eight weeks. Average effects were modest, and some people respond strongly. Serotonin rises within hours of a dose but mood shifts over weeks, a clue that they work through slower changes.
522 trials116,477 adultsLancet 2018
Don’t stop suddenly
Coming off antidepressants can cause withdrawal effects. The 2022 review’s own authors advised talking to a health professional first. If you want to stop, plan a gradual reduction with your prescriber.
The story you believe changes what you do
An explanation with no levers makes recovery look further away. You have many: sleep, movement, people, therapy, medication and purpose all act on depression. You can pull more than one at once.
04 · Purpose
Motivation comes after you start.
Depression says to wait until you feel like it. Waiting makes the day smaller, and a smaller day gives you fewer reasons to feel like anything. Purpose here doesn’t mean a life mission. It means one small thing that matters to you, done before the feeling arrives.
The shrinking loop
Waiting to feel like it
- Feel flat. Nothing seems worth the effort.
- Wait to feel like it. Cancel, put off, stay in.
- Do less. Fewer people, less movement, more time to ruminate.
- Fewer good moments. Less contact, less achievement, less pleasure.
The activation loop
Acting on what matters
- Pick one small thing that matters. Small enough that starting is easy.
- Do it before you feel like it. Schedule it, then follow the plan, not the mood.
- Notice what it gave you. A little contact, achievement or pleasure. Even 1% counts.
- Slightly more energy. Enough to pick the next small thing.
Behavioural activation · Lancet 2016
Scheduling what matters is a therapy
In the COBRA trial, 440 adults with depression got either behavioural activation from junior workers with five days’ training, or CBT from therapists. A year on, both groups had dropped from about 17 to about 8 on the PHQ-9, the same scale as section 02. Activation cost about a fifth less.
440 adultsPHQ-9 ~17 → ~8~21% cheaper
Exercise · BMJ 2024
Moving counts, and harder counts more
A review of 218 trials found walking or jogging, yoga and strength training each brought moderate drops in depression. Harder sessions helped more than light ones. Yoga and strength training had the fewest dropouts. The authors rated the certainty of this evidence low to very low, so treat the size of the effect with caution.
218 trials14,170 peoplewalk · yoga · strength
Ask what matters, not what you feel like.
“What would I do today if it mattered?” gets a different answer from “What do I feel like doing?” The first question is where purpose starts. The 4Cs give you four places to look.
05 · Small moves
One small move per mode, before you feel like it.
Depression flattens all four modes at once. Each card names how, and three moves sized for a flat day. Start with Chill and Constructive; rhythm and one finished thing make the other two easier.
Write it down while you can see it.
Plans made on a better day carry you through a flat one. These save on this device and come with you when you copy or download.
Saves as you type.
06 · When to get help
See someone soon if any of these are true.
Small moves help, and they work best alongside proper care. Each of these is a reason to talk to a person, not a page.
You’re thinking about death, suicide or hurting yourself
Or that people would be better off without you. You don’t need to be sure it’s serious enough to call.
Low mood with voices, or beliefs others find strange
Hearing or seeing things others don’t, or becoming convinced of things that worry the people around you. This needs an assessment today: call your GP or go to an emergency department.
It’s been two weeks or more and life is slipping
Work, study, home or relationships are suffering. Book a GP appointment this week. A GP also checks for physical causes that look like depression, such as an underactive thyroid, anaemia, sleep apnoea or a medication side effect.
You’ve also had highs
Stretches of unusual energy, little need for sleep, racing ideas or risky spending. Tell your GP before starting an antidepressant, because depression in bipolar disorder is treated differently.
You’re pregnant or have a new baby
Depression around pregnancy and birth is common and treatable, for mums and dads.
You’re drinking or using more to get through
Alcohol eases the evening and deepens the next day.
How care works in Australia.
Start here
Your GP
Book with your usual GP or the practice you’re enrolled with in MyMedicare. Say it plainly: “I think I might be depressed.” Bring your PHQ-9 score.
Better Access
Plan and referral
A mental health treatment plan and a written referral give you up to 10 individual and 10 group sessions a calendar year with Medicare rebates.
Free, no referral
Start this week
Medicare Mental Health Check In offers free low-intensity CBT for people 16 and over on 1800 595 212. MindSpot runs free online courses for adults.
07 · Someone you love
If someone you love has gone flat.
You can’t lift it for them. You can make the next step easier and keep showing up.
What helps
- Ask directly about suicide if you’re worried. Asking doesn’t put the idea in someone’s head. It tells them they’re allowed to say it.
- Skip “cheer up”. It aims at happiness. Invite them to do one small thing with you instead: a walk, a coffee, an errand.
- Make the first step smaller. Offer to book the GP, drive them there, or sit with them while they call.
- Keep inviting. Expect “no” for a while. The invitation itself tells them they still belong.
- Look after yourself too. Most services below support family and friends as well.
If you’re worried about their safety
Stay with them if you can, and call Lifeline together. If they’re in immediate danger, call 000. You can also call Lifeline about someone else, any time.
08 · Help
People whose job this is.
Free and confidential in Australia. Calling isn’t admitting defeat. It’s Caring and Curious, pointed at yourself.
Emergency000Immediate danger to you or anyone else.
Lifeline13 11 1424/7 crisis support, whatever’s going on.
Suicide Call Back Service1300 659 46724/7 counselling if suicide is on your mind or someone else’s.
Beyond Blue1300 22 463624/7 support for depression, anxiety and feeling overwhelmed.
Medicare Mental Health1800 595 212Free Check In program, 16+, no referral or diagnosis needed.
13YARN13 92 7624/7 crisis support for Aboriginal and Torres Strait Islander people.
MensLine Australia1300 78 99 7824/7 counselling for men, about anything.
PANDA1300 726 306Perinatal anxiety and depression, for expecting and new parents.
QLife1800 184 527LGBTIQ+ peer support and referral, every afternoon and evening.
Kids Helpline1800 55 180024/7 counselling for young people aged 5 to 25.
MindSpotmindspot.org.auFree online assessment and courses for adults.
Your GPBook this weekAsk about a mental health treatment plan and a referral.
Outside Australia, findahelpline.com lists free, confidential support by country.
Sources11
- Solomon A. Depression, the secret we share. TEDxMet, 2013.
- Ford BQ, Shallcross AJ, Mauss IB, et al. Desperately seeking happiness: valuing happiness is associated with symptoms and diagnosis of depression. J Soc Clin Psychol, 2014.
- Kroenke K, Spitzer RL, Williams JBW. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med, 2001. Questionnaire (PDF).
- Moncrieff J, Cooper RE, Stockmann T, et al. The serotonin theory of depression: a systematic umbrella review of the evidence. Mol Psychiatry, 2023 (online July 2022). Summary.
- Erritzoe D, Godlewska BR, Rizzo G, et al. Brain serotonin release is reduced in patients with depression: a [11C]Cimbi-36 PET study with a d-amphetamine challenge. Biol Psychiatry, 2023 (online December 2022). Summary.
- Kemp JJ, Lickel JJ, Deacon BJ. Effects of a chemical imbalance causal explanation on individuals’ perceptions of their depressive symptoms. Behav Res Ther, 2014.
- Cipriani A, Furukawa TA, Salanti G, et al. Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder. Lancet, 2018. NIHR summary.
- Richards DA, Ekers D, McMillan D, et al. Cost and outcome of behavioural activation versus CBT for depression (COBRA). Lancet, 2016. NIHR summary.
- Noetel M, Sanders T, Gallardo-Gómez D, et al. Effect of exercise for depression: systematic review and network meta-analysis. BMJ, 2024.
- Australian Government Department of Health. Better Access fact sheet, March 2026.
- Australian Government. Medicare Mental Health Check In, 2026.
Turning it up
You don’t have to feel like it to start.
Pick one small move from one mode and do it today. Then tell one person how it’s really been. Vitality comes back in steps, and the first one is usually small.
For a body-first way to settle, try the Vagus nerve breathing guide