Deep dive
What depression does to a lifespan, treated and untreated
Updated 2026-08-30
Depression, by the numbers
of life expectancy with untreated recurrent depression. With active treatment the picture changes: managed depression carried a 24% lower death risk over 8 years, landing near people without depression (Chesney 2014; Gallo, BMJ 2013).
The comorbidity toll
Change in risk when depression is present, versus without it
The short version
- •Untreated recurrent depression shortens life by an estimated 7 to 11 years (Chesney, World Psychiatry 2014), and because it is so common, mood disorders account for the largest share of deaths attributable to mental illness overall (Walker, JAMA Psychiatry 2015).
- •The years are mostly lost to the body, not to suicide: depression raises the risk of coronary heart disease by about 80% (Nicholson, Eur Heart J 2006), type 2 diabetes by 60% (Mezuk, Diabetes Care 2008), and stroke by 45% (Pan, JAMA 2011). After a heart attack, depression doubles the risk of dying (van Melle, Psychosom Med 2004).
- •It works through two channels at once: biology (chronic inflammation, stress-hormone dysregulation, abdominal weight gain; Penninx, BMC Medicine 2013) and behavior (depressed patients are three times more likely to skip prescribed treatment; DiMatteo, Arch Intern Med 2000).
- •Treatment interrupts the chain. In the IMPACT trial, older adults whose depression was actively managed had a 24% lower risk of death over 8 years, ending up near people without depression (Gallo, BMJ 2013). Antidepressants beat placebo across all 21 drugs tested (Cipriani, Lancet 2018), and exercise rivals both (Noetel, BMJ 2024).
- •The practical conclusion: treat depression like a chronic physical illness. Screen for it, treat it to remission, and screen the heart and metabolism alongside it.
Depression is usually discussed as suffering, and it is. But it is also one of the most underrated longevity risks in medicine: untreated, it costs about as many years as a lifetime of heavy smoking, and almost nobody knows why. The reason is a chain that runs through the body. Depression feeds heart disease, diabetes, and stroke through inflammation and stress physiology, and it quietly dismantles the behaviors that would have caught them: the medications go untaken, the walks stop, the checkups lapse. The hopeful part is that the chain has a weak link. Treat the depression, and the death rates move most of the way back to normal. Here is the evidence for each link, and where to cut it.
Untreated, the cost is 7 to 11 years
Recurrent depression shortens life by an estimated 7 to 11 years (Chesney, World Psychiatry 2014). Per person that is smaller than psychosis or addiction, but depression is so common that mood disorders account for the largest share of deaths attributable to mental illness overall (Walker, JAMA Psychiatry 2015, meta-analysis of 1.7 million patients).
Do this
Two weeks or more of low mood, flat interest, or broken sleep is a screening moment, not a character phase. A PHQ-9 takes two minutes online and gives you a number to bring to a doctor.
Even mild depression carries a mortality cost
Across 247 prospective studies with over 100,000 depressed participants, depression raised the risk of dying by roughly half, and the excess held after adjusting for the diseases people already had (Cuijpers, Am J Psychiatry 2014). Subthreshold depression, symptoms that never reach a formal diagnosis, carried a mortality risk not far behind major depression (Cuijpers, Br J Psychiatry 2013).
Do this
Do not wait to qualify for a diagnosis before acting. Persistent low-grade flatness deserves the same response as the full syndrome: talk to someone, move daily, and re-screen in a month.
The heart takes the biggest hit
In healthy people, depression predicts about 80% higher risk of developing coronary heart disease (Nicholson, Eur Heart J 2006, meta-analysis of 146,538 participants). Once heart disease exists, the interaction turns lethal: depression after a heart attack carries 2 to 2.5 times the risk of death and further cardiac events (van Melle, Psychosom Med 2004).
Do this
Treat depression and heart risk as one project. If you have depression, know your blood pressure and lipid numbers. If you or a family member has had a heart attack, insist on depression screening during recovery; it is prognostic, not cosmetic.
Diabetes and stroke follow the same track
Depression raises the risk of developing type 2 diabetes by about 60% (Mezuk, Diabetes Care 2008) and the risk of stroke by about 45% (Pan, JAMA 2011, meta-analysis of 317,540 participants). The diabetes link runs both ways: diabetes raises depression risk by about 15%, creating a loop where each condition worsens the other.
Do this
If you have depression, get an HbA1c into your yearly labs; if you have diabetes and your motivation for managing it has collapsed, screen the mood, because treating it is often what restores the self-care.
The biology: inflammation, cortisol, and belly fat
Depression is not only in the brain. Depressed patients show chronic low-grade inflammation, hyperactivity of the stress-hormone (HPA) axis, autonomic dysregulation, and a tilt toward abdominal obesity and unhealthy lipids, each a direct accelerant of cardiovascular and metabolic disease (Penninx, BMC Medicine 2013). This is why the mortality excess persists even in studies that adjust for health behaviors.
Do this
You cannot willpower your cortisol down, but the things that treat depression, exercise, sleep repair, and effective therapy or medication, each also quiet this biology. That is the double return on treating it properly.
The behavior channel: the care stops happening
Depression triples the odds of not following medical treatment, from cardiac medication to rehab attendance (DiMatteo, Arch Intern Med 2000). Add higher smoking rates, less physical activity, worse sleep, and more drinking, and depression functions as a force multiplier on every other risk a person carries.
Do this
During low stretches, protect the boring infrastructure first: medications taken, appointments kept, a daily walk. If adherence is slipping, tell your doctor the reason is mood, not forgetfulness; it changes the fix.
Suicide is real, but it is the smaller share
Suicide risk in depression is genuinely elevated and deserves direct attention. But across mental disorders, only about 17% of excess deaths come from suicide and injury, while about two-thirds come from natural causes, mostly the heart and metabolic diseases above (Walker, JAMA Psychiatry 2015). Preventing the physical deaths is the larger, and more neglected, half of the problem.
Do this
Take any thoughts of self-harm seriously and seek help immediately (in the US, call or text 988). And for the long game, treat the physical screening in this article as suicide prevention's quieter twin.
Treated, the mortality gap mostly closes
In the IMPACT trial, older adults whose depression was actively managed with collaborative care had a 24% lower risk of death over 8 years than those left in usual care, ending with mortality similar to people without depression (Gallo, BMJ 2013). The tools all work: every one of 21 antidepressants beat placebo (Cipriani, Lancet 2018), and exercise reduced depression with effects comparable to therapy and medication across 218 randomized trials (Noetel, BMJ 2024).
Do this
Treat to remission, not just improvement. If the first medication or therapist does not work, that is expected, not failure; switching or combining is the protocol. And prescribe yourself movement alongside: 150 minutes a week, counted like a dose.
Manage it like a chronic physical illness
The conditions that shorten life alongside depression are all screenable and treatable, but only if someone looks: depression care that includes physical monitoring is exactly what produced the near-normal death rates in collaborative care (Gallo, BMJ 2013). The failure mode is a system, or a person, that treats the mood and forgets the body, or treats the body and never asks about the mood.
Do this
If depression is part of your history, put four numbers on an annual cadence: blood pressure, lipids, HbA1c, and a PHQ-9. Relapses are common and not a verdict; catching one early is the whole game.
How to tell if yours is good
Signals you can read yourself, starting today, and what a good reading looks like.
Mood
Low days pass within days; interest and energy come back on their own
Treatment
If diagnosed: an active plan (therapy, medication, or both) reviewed within the last year
Heart and metabolic numbers
Blood pressure, lipids, and HbA1c checked within the last year
Adherence
Prescriptions and appointments happen even during low stretches
Movement
150+ minutes a week of heart-rate-raising activity
Relapse plan
You know your early warning signs and who you would call
Check your own risk
5 quick questions about you, not the article. You get a personal readout of where your risks sit.
Pick an answer to reveal the numbers: life-model years where an answer maps to one (+0y = measured, no effect on its own), check points otherwise (+2 pts working for you, +1 pt worth tightening, 0 pts elevated risk).
1. How often do you feel down, flat, or without interest?
2. Have you been diagnosed with a mental health condition — and is it being actively treated right now?
3. If depression is part of your history: were your blood pressure, lipids, and HbA1c checked in the last year?
4. During low stretches, do prescriptions and appointments still happen?
5. Heart-rate-raising movement: how many days a week do you get 30+ minutes?
Now score your own
These two-minute checks turn this research into your numbers, and the years they are worth.
Sources
- Chesney, Goodwin & Fazel, World Psychiatry 2014 — all-cause and suicide mortality meta-review
- Walker, McGee & Druss, JAMA Psychiatry 2015 — mortality in mental disorders meta-analysis
- Cuijpers et al., Am J Psychiatry 2014 — excess mortality in depression, 247-study meta-analysis
- Cuijpers et al., Br J Psychiatry 2013 — mortality in major versus subthreshold depression
- Nicholson, Kuper & Hemingway, Eur Heart J 2006 — depression and coronary heart disease meta-analysis
- van Melle et al., Psychosom Med 2004 — depression after myocardial infarction and prognosis
- Mezuk et al., Diabetes Care 2008 — depression and type 2 diabetes, bidirectional meta-analysis
- Pan et al., JAMA 2011 — depression and risk of stroke meta-analysis
- Penninx et al., BMC Medicine 2013 — biological mechanisms of the somatic consequences of depression
- DiMatteo, Lepper & Croghan, Arch Intern Med 2000 — depression and treatment noncompliance meta-analysis
- Cipriani et al., Lancet 2018 — comparative efficacy of 21 antidepressants, network meta-analysis
- Gallo et al., BMJ 2013 — depression care management and 8-year mortality (IMPACT trial)
- Noetel et al., BMJ 2024 — exercise for depression network meta-analysis
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YapSpan estimates are for reflection and entertainment only. They are not medical advice, a diagnosis, or a prediction of any individual outcome.