psychiatric medications being prescribed on pad

The World Health Organization (WHO) reports that approximately 300 million people in the world meet clinical criteria for depressive disorder, and approximately 24 million people in the world meet clinical criteria for schizophrenia.

That’s about 1 in 25 people with depression, and 1 in 300 people with schizophrenia.

In addition, the WHO indicates that in low and middle-income countries, 75 percent of people who need treatment for depression do not receive specialized treatment for depression, and 70 percent of people with schizophrenia do not receive specialized treatment for schizophrenia. Factors affecting these low treatment rates include stigma, inaccurate information, incorrect diagnoses, a lack of trained providers, a lack of resources to provide care, and lack of resources to access care when available.

In the U.S., our treatment situation is far different. We have the resources to both provide care for those who can access it themselves, and the resources to offer support to people without the means to access care themselves. Stigma around mental health disorders and mental health treatment is on the decline, and awareness around the basic facts of mental health and treatment for mental health disorders is on the rise. Barriers to care slowly fall as access to treatment resources, availability of providers, and coverage/reimbursement from public and private providers increase every year.

This article will discuss a new development in treatment for depression and schizophrenia: the use of a technique called pharmacogenomics, which refers to the use of individual genetic information – in the form of a personal genetic profile – to determine what psychiatric medication might be most effective for that individual, based on their specific genetic profile.

Depression in the U.S.: Facts and Figures

Recent developments – such as the impact of the pandemic on rates of mental health disorders and our recognition of the importance of expanding mental health treatment – place the need for advances in overall knowledge and understanding of mental health disorders and their treatment front and center in our awareness.

To expand our personal knowledge and understanding of these critical topics, let’s take a look at the statistics on depression and schizophrenia in the U.S.

We’ll start with the latest information on depression.

Data from the National Institutes of Health (NIH) show the following rates of depression for the year 2020:

  • Total:
    • 4% of adults reported at least one major depressive episode
    • 6% of adults reported at least one major depressive episode with severe impairment
  • By Gender:
    • Adult females: 10.5%
    • Adult males: 6.2%
  • By Age Group, Adults:
    • 18-25: 17.0%
    • 26-49: 9.1%
    • 50+: 5.4%
  • By Race/Ethnicity, Adults:
    • Hispanic: 7.0%
    • White: 9.5%
    • Black/African American: 6.0%
    • Asian: 4.2%
    • Indigenous American: 4.2%
    • Two or more: 15.9%

Now let’s look at the statistics on treatment for depression among adults in 2020:

  • Major depressive episode: 66.0% adults 18+ received treatment
  • Major depressive episode with severe impairment: 71.0% received treatment

Finally, a study published by the Centers for Disease Control (CDC) on rates of prescription anti-depressant use between 2013 and 2018 shows the following:

  • Total: 13.2% of adults
  • By Gender:
    • Females: 17.7%
    • Males: 8.4%

Next, let’s look at the prevalence and treatment rates for schizophrenia in 2020.

Schizophrenia in the U.S.: Facts and Figures

Before we share these numbers, we’ll offer this disclaimer from the National Institute of Mental Health (NIMH):

“Precise prevalence estimates of schizophrenia are difficult to obtain due to clinical and methodological factors such as the complexity of schizophrenia diagnosis, its overlap with other disorders, and varying methods for determining diagnoses.”

With that in mind, here are the statistics.

Schizophrenia in the U.S. and World

  • Clinical diagnosis of schizophrenia and/or related psychotic disorders:
    • Between 0.25% and 0.64%
    • That’s between 525,000 and 1,344,000 people
  • Worldwide prevalence of schizophrenia and/or related psychotic disorders:
    • Between 0.33% and 0.75%
    • That’s between 19,800,000 and 45,000,000 people

Now let’s look at treatment estimates for schizophrenia, which we’ll derive by inference. The NIH data above comes from a resource called the National Survey on Drug Use and Health (NSDUH). They collect specific data on depression, but not other named disorders. They do, however, collect data on serious mental illness (SMI), and report rates of treatment for people with SMI. Since schizophrenia is a serious mental illness, we’ll use SMI data to get a broad idea of treatment rates for schizophrenia. However, please keep in mind this data is to give us a general feel for treatment rates: these numbers are not definitive, with regards to treatment for schizophrenia and/or related psychotic disorders.

Treatment and Medication for Adults With Serious Mental Illness in the U.S.

  • Among 14.2 million adults diagnosed with serious mental illness in 2020:
    • 64.5% received treatment
    • That’s 923,000 people
  • Among 14.2 million adults diagnosed with serious mental illness in 2020:
    • 55.9% received prescription medication
    • That’s 793,000 people

Those facts and figures offer a reliable, evidence-based picture of the current situation in the U.S. and worldwide with regards to depression and schizophrenia. Millions of people in the U.S. and around world meet clinical criteria for a diagnosis of major depressive disorder (MDD), and millions of people around meet the clinical criteria for diagnosis of schizophrenia.

Alongside those diagnoses, millions of people also take prescription medication for these disorders: people with MDD often take antidepressants, and people with schizophrenia often take antipsychotics. That’s what a study published recently got our attention: it focuses on how we can identify the best medication for people diagnosed with MDD or schizophrenia.

New Methods Help May Help Clinicians Determine Optimal Medication

Published in October 2022, the study “Pharmacogenomics in Treatment of Depression and Psychosis: An Update” examined how a new technique – we mention it briefly in the introduction to this article – than can help streamline and improve the treatment process for people who need medication for depressive or psychotic disorders.

First, let’s clarify something:

What does pharmacogenomics mean?

We give a brief definition above, but we’ll remind you now:

Pharmacogenomics the branch of genetics concerned with the way in which an individual’s genetic attributes affect the likely response to therapeutic drugs.

In this study, researchers wanted to learn how they can use pharmacogenomics to predict how psychiatric patients respond to the most common medications prescribed for major depressive disorder (MDD) and schizophrenia.


Anyone with depression or a psychotic disorder – or with a family member with depression or a psychotic disorder – knows that the process around finding the right medication can be frustrating and time-consuming. Antidepressants can take one to two weeks to take effect, at minimum. With changes in dosages, changes in medications, and various other factors, it’s not unusual for a person who takes antidepressants to go through a trial-and-error period of six months to a year before they find a medication and dosage that works for them. In the case of antipsychotics, some take effect within hours or days, some take up to four to six weeks, and for some people, medication has little effect.

Researchers in the study also report the following information about the effectiveness of antidepressant and antipsychotic medications, based on their review of several large-scale meta-analyses on depression and schizophrenia.

For antidepressants:

  • 42% of patients reported a good response
  • 53% if patients reported a minimal response

For antipsychotics:

  • 23% reported a good response
  • 51% reported a minimal response

These response rates, paired with the time it takes to find the most effective medication for each individual, indicate that, as a whole, there’s room for improvement: that’s where pharmacogenetics comes in. The study authors hypothesize that they can identify and utilize pharmacogenomic biomarkers to streamline the process, and improve outcomes for people with depression and schizophrenia.

Let’s see whether the data they uncovered confirmed their hypothesis.

Can Pharmacogenomics Improve Treatment Outcomes for Depression and Schizophrenia?

It’s widely known that there’s significant variation in the way psychiatric patients respond to psychiatric medications. Many factors play a role in this phenomenon, such as heredity, environment, individual physical characteristics, and diet. The goal of this research is to determine whether the presence of specific genetic biomarkers can predict how patients respond to various medications in a way that awareness of previously researched non-genetic factors cannot.

Here’s what the study authors found:

  • Five studies showed using pharmacogenomic biomarkers to target medication improved treatment outcomes for people with MDD
  • Results from 14 meta-analyses showed clinically relevant differences – based on pharmacogenomic biomarkers – in reactions to ten common antipsychotic medications

Based on these results, researchers concluded the following:

Pharmacogenomic information can improve treatment outcomes for patients with major depressive disorder (MDD) and predict dose-response reactions in patients with schizophrenia.

That’s an important finding.

It may help reduce the time it takes for patients and clinicians to find an effective medication that reduces symptoms of depression and psychotic disorders such as schizophrenia. As we mention above, that time-lag is often frustrating for patients. It takes energy, and in some cases, has a negative impact on their faith in the treatment process and the belief they can heal. Eliminating the trial and error nature of prescribing these medications would represent a major step forward in the treatment of depression and schizophrenia.

Here’s the process they suggest for implementing the use of pharmacogenomic information in prescribing medication for depression and schizophrenia:

  1. Patient supplies genomic DNA
  2. Clinicians create a personal genetic profile
  3. Clinicians use profile to select specific medication and dosage
  4. Follow up to determine stability of effectiveness

However, before clinicians can apply this consistently in practice, additional large prospective studies are required.

The authors of the study conclude with this inisight:

“We believe that a broader use of genetically based psychiatric drug therapy is realistic in the foreseeable future and will further contribute to improving psychiatric treatment outcomes, with reduced costs for psychiatric drug treatment and improved mental health in the population.”

We’re optimistic.

All the research on this topic points in the right direction: improved outcomes for people in treatment depression and/or schizophrenia.

We’ll keep an eye on the research, and report new results here as soon as they’re available.