In this entry we present the latest estimates of mental health disorder prevalence and the associated disease burden. Most of the estimates presented in this entry are produced by the Institute for Health Metrics and Evaluation and reported in their flagship Global Burden of Disease study.
For 2017 this study estimates that 792 million people lived with a mental health disorder. This is slightly more than one in ten people globally (10.7%)
Mental health disorders are complex and can take many forms. The underlying sources of the data presented in this entry apply specific definitions (which we describe in each relevant section), typically in accordance with WHO’s International Classification of Diseases (ICD-10). This broad definition incorporates many forms, including depression, anxiety, bipolar, eating disorders and schizophrenia.
Mental health disorders remain widely under-reported — in our section on Data Quality & Definitions we discuss the challenges of dealing with this data. This is true across all countries, but particularly at lower incomes where data is scarcer, and there is less attention and treatment for mental health disorders. Figures presented in this entry should be taken as estimates of mental health disorder prevalence — they do not reflect diagnosis data (which would provide the global perspective on diagnosis, rather than actual prevalence differences), but are imputed from a combination of medical, epidemiological data, surveys and meta-regression modelling where raw data is unavailable. Further information can be found here.
It is also important to keep in mind that the uncertainty of the data on mental health is generally high so we should be cautious about interpreting changes over time and differences between countries.
The data shown in this entry demonstrate that mental health disorders are common everywhere. Improving awareness, recognition, support and treatment for this range of disorders should therefore be an essential focus for global health.
The table here provides a summary of the data which follows on mental health and substance use disorders. Clicking on a given disorder will take you to the relevant section for further data and information.
Related entries:
The Global Burden of Disease study aggregates substance use disorders (alcohol and drug use disorders) with mental health disorders in many statistics. In the discussion of the prevalence we have followed this practice, but we will change it in future updates of this research.
We address substance use disorders (alcohol and drug use disorders) in separate entries on Substance Use and Alcohol Consumption.
| Disorder | Share of global population with disorder (2017) [difference across countries] | Number of people with the disorder (2017) | Share of males:females with disorder (2017) |
|---|---|---|---|
| Any mental health disorder | 10.7% | 792 million | 9.3% males 11.9% females |
| Depression | 3.4% [2-6%] | 264 million | 2.7% males 4.1% females |
| Anxiety disorders | 3.8% [2.5-7%] | 284 million | 2.8% males 4.7% females |
| Bipolar disorder | 0.6% [0.3-1.2%] | 46 million | 0.55% males 0.65% females |
| Eating disorders(clinical anorexia & bulimia) | 0.2% [0.1-1%] | 16 million | 0.13% males 0.29% females |
| Schizophrenia | 0.3% [0.2-0.4%] | 20 million | 0.26% males 0.25% females |
| Any mental or substance use disorder | 13% [11-18%] | 970 million | 12.6% males 13.3% females |
| Alcohol use disorder | 1.4% [0.5-5%] | 107 million | 2% males 0.8% females |
| Drug use disorder (excluding alcohol) | 0.9% [0.4-3.5%] | 71 million | 1.3% males 0.6% females |
Prevalence of mental health and substance use disorders
The predominant focus of this entry is the prevalence and impacts of mental health disorders (with Substance Use and Alcohol Use disorders covered in individual entries). However, it is useful as introduction to understand the total prevalence and disease burden which results from the broad IHME and WHO category of ‘mental health and substance use disorders’. This category comprises a range of disorders including depression, anxiety, bipolar, eating disorders, schizophrenia, intellectual developmental disability, and alcohol and drug use disorders.
Mental and substance use disorders are common globally
In the map we see that globally, mental and substance use disorders are very common: around 1-in-7 people (15%) have one or more mental or substance use disorders.
Prevalence of mental health disorders by disorder type
It’s estimated that 970 million people worldwide had a mental or substance use disorder in 2017. The largest number of people had an anxiety disorder, estimated at around 4 percent of the population.
Prevalence of mental health disorders by genders
The scatterplot compares the prevalence of these disorders between males and females. Taken together we see that in most countries this group of disorders is more common for women than for men. However, as is shown later in this entry and in our entries on Substance Use and Alcohol, this varies significantly by disorder type: on average, depression, anxiety, eating disorders, and bipolar disorder is more prevalent in women. Gender differences in schizophrenia prevalence are mixed across countries, but it is typically more common in men. Alcohol and drug use disorders are more common in men.
Deaths from mental health and substance use disorders
The direct death toll from mental health and substance use disorders is typically low. In this entry, the only direct death estimates result from eating disorders, which occur through malnutrition and related health complications. Direct deaths can also result from alcohol and substance use disorders; these are covered in our entry on Substance Use.
However, mental health disorders are also attributed to significant number of indirect deaths through suicide and self-harm. Suicide deaths are strongly linked — although not always attributed to — mental health disorders. We discuss the evidence of this link between mental health and suicide in detail later in this entry.
In high-income countries, meta-analyses suggest that up to 90 percent of suicide deaths result from underlying mental and substance use disorders. However, in middle to lower-income countries there is evidence that this figure is notably lower. A study by Ferrari et al. (2015) attempted to determine the share disease burden from suicide which could be attributed to mental health or substance use disorders.1
Based on review across a number of meta-analysis studies the authors estimated that only 68 percent of suicides across China, Taiwan and India were attributed to mental health and substance use disorders. Here, studies suggest a large number of suicides result from the ‘dysphoric affect’ and ‘impulsivity’ (which are not defined as a mental and substance use disorder). It is important to understand the differing nature of self-harm methods between countries; in these countries a high percentage of self-harming behaviours are carried out through more lethal methods such as poisoning (often through pesticides) and self-immolation. This means many self-harming behaviours can prove fatal, even if there was no clear intent to die.
As a result, direct attribution of suicide deaths to mental health disorders is difficult. Nonetheless, it’s estimated that a large share of suicide deaths link back to mental health. Studies suggest that for an individual with depression the risk of suicide is around 20 times higher than an individual without.
Disease burden of mental health and substance use disorders
Health impacts are often measured in terms of total numbers of deaths, but a focus on mortality means that the burden of mental health disorders can be underestimated2 Measuring the health impact by mortality alone fails to capture the impact that mental health disorders have on an individual’s wellbeing. The ‘disease burden‘ – measured in Disability-Adjusted Life Years (DALYs) – considers not only the mortality associated with a disorder, but also years lived with disability or health burden. The map shows DALYs as a share of total disease burden; mental and substance use disorders account for around 5 percent of global disease burden in 2017, but this reaches up to 10 percent in several countries. These disorders have the highest contribution to overall health burden in Australia, Saudi Arabia and Iran.
Depression
Definition of depression
Depressive disorders occur with varying severity. The WHO’s International Classification of Diseases (ICD-10) define this set of disorders ranging from mild to moderate to severe. The IHME adopt such definitions by disaggregating to mild, persistent depression (dysthymia) and major depressive disorder (severe).
All forms of depressive disorder experience some of the following symptoms:
- (a) reduced concentration and attention;
- (b) reduced self-esteem and self-confidence;
- (c) ideas of guilt and unworthiness (even in a mild type of episode);
- (d) bleak and pessimistic views of the future;
- (e) ideas or acts of self-harm or suicide;
- (f) disturbed sleep
- (g) diminished appetite.
Mild persistent depression (dysthymia) tends to have the following diagnostic guidelines:
“Depressed mood, loss of interest and enjoyment, and increased fatiguability are usually regarded as the most typical symptoms of depression, and at least two of these, plus at least two of the other symptoms described on page 119 (for F32.-) should usually be present for a definite diagnosis. None of the symptoms should be present to an intense degree. Minimum duration of the whole episode is about 2 weeks. An individual with a mild depressive episode is usually distressed by the symptoms and has some difficulty in continuing with ordinary work and social activities, but will probably not cease to function completely.”
Severe depressive disorder tends to have the following diagnostic guidelines:
“In a severe depressive episode, the sufferer usually shows considerable distress or agitation, unless retardation is a marked feature. Loss of self-esteem or feelings of uselessness or guilt are likely to be prominent, and suicide is a distinct danger in particularly severe cases. It is presumed here that the somatic syndrome will almost always be present in a severe depressive episode. During a severe depressive episode it is very unlikely that the sufferer will be able to continue with social, work, or domestic activities, except to a very limited extent.”
The series of charts below present the latest global estimates of the prevalence and disease burden of depressive disorders. Depressive disorders, as defined by the underlying source, cover a spectrum of severity ranging from mild persistent depression (dysthymia) to major (severe) depressive disorder. The data presented below includes all forms of depression across this spectrum.
Prevalence of depressive disorders
The share of population with depression ranges mostly between 2% and 6% around the world today. Globally, older individuals (in the 70 years and older age bracket) have a higher risk of depression relative to other age groups.
Anxiety disorders
Definition of anxiety disorders
Anxiety disorders arise in a number of forms including phobic, social, obsessive compulsive (OCD), post-traumatic disorder (PTSD), or generalized anxiety disorders.
The symptoms and diagnostic criteria for each subset of anxiety disorders are unique. However, collectively the WHO’s International Classification of Diseases (ICD-10) note frequent symptoms of:
“(a) apprehension (worries about future misfortunes, feeling “on edge”, difficulty in concentrating, etc.);
(b) motor tension (restless fidgeting, tension headaches, trembling, inability to relax);
(c) autonomic overactivity (lightheadedness, sweating, tachycardia or tachypnoea, epigastric discomfort, dizziness, dry mouth, etc.).”
The series of charts here present global data on the prevalence and disease burden which results from this range of anxiety disorders.
Prevalence of anxiety disorders
The prevalence of anxiety disorders across the world varies from 2.5 to 7 percent by country. Globally an estimated 284 million people experienced an anxiety disorder in 2017, making it the most prevalent mental health or neurodevelopmental disorder. Around 63 percent (179 million) were female, relative to 105 million males.
DALYs from anxiety disorders
The chart found here shows the health burden of depression as measured in Disability Adjusted Life Years (DALYs) per 100,000. A time-series perspective on DALYs by age is here.
Hannah Ritchie and Max Roser (2018) – “Mental Health”. Published online at OurWorldInData.org.
This is part 1 of two part article. Read part 2 here
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