Prevalence of Mental Health Disorders

Mental health statistics: the most common mental health problems: 

• Depression

• Bipolar disorder

• Schizophrenia and other psychoses

• Dementia

Common mental disorders refer to two main diagnostic categories: depressive disorders and anxiety disorders. These disorders are highly prevalent in the population (hence why they are considered ‘common’), and impact on the mood or feelings of affected persons; symptoms range in terms of their severity (from mild to severe) and duration (from months to years). These disorders are diagnosable health conditions, and are distinct from feelings of sadness, stress, or fear that anyone can experience from time to time in their lives.

At a global level, over 300 million people are estimated to suffer from depression, equivalent to 4.4% of the world’s population.

Reliable, up-to-date estimates of the proportion of a general population affected by different diseases or health conditions are a critical ingredient of effective health policy, planning, and evaluation. Numerous large-scale surveys of the prevalence of mental disorders in adults in the general population have been carried out since the 1980s based on self-reported symptoms assessed by standardized structured interviews, usually carried out over the phone. Mental disorders have been found to be common, with over a third of people in most countries reporting sufficient criteria to be diagnosed at some point in their life. The World Health Organization (WHO) reported in 2001 that about 450 million people worldwide suffer from some form of mental disorder or brain condition and that one in four people meet criteria at some point in their life.

The World Health Organization is currently undertaking a global survey of 26 countries in all regions of the world, based on ICD and DSM criteria. The first published figures on the 14 country surveys completed to date indicate that, of those disorders assessed, anxiety disorders are the most common in all but 1 country (prevalence in the prior 12-month period of 2.4% to 18.2%) and mood disorders next most common in all but 2 countries (12-month prevalence of 0.8% to 9.6%), while substance disorders (0.1–6.4%) and impulse-control disorders (0.0–6.8%) were consistently less prevalent. However, these numbers and statistics are significantly underestimated, due to poor diagnosis (especially in countries without affordable access to mental health services) and low reporting rates, in part because of the predominant use of self-report data.

Although mental illness is very common, it isn’t common for most people to admit that there is a problem. For various reasons, individuals who have psychological disorders or simply battle with their mental health, often they hesitate to come forward. They may not feel comfortable seeking out a diagnosis because no one really wants to admit that they may not be “normal”. As a result, they cannot adequately meet their mental health needs, and more often than not, the person will begin self-medicating with drugs and/or alcohol keeps unwelcome thoughts and feelings at bay, keeping the person in a vicious cycle of mental illness and substance abuse.