A person's side profile and sound waves depicting speechShare on Pinterest
Scientists have discovered that changes in speech may be an early sign of depression. Johanna Lindberg/EyeEm/Getty Images
  • Depression is a common mental illness that can lead to debilitating symptoms.
  • To reach an accurate clinical diagnosis, doctors will carefully collect data on a person’s symptoms, history, and presentation.
  • Data from a recent study found that examining speech may be a critical way to help identify depression in people that have not yet been diagnosed.
  • Further research is needed to understand how speech changes among people who are depressed.

Depression is a significant mental health disorder. Accurate diagnosis ensures people get the guidance and help they need to manage their depression. Diagnosing a person with depression involves looking at various behavior changes that indicate depression.

A​ recent study published in BMC Psychiatry investigated how looking at speech patterns may be useful in identifying people with depression who have not yet received a diagnosis.

The methods studied may help detect early warning signs of depression.

Major Depressive Disorder, also just called depression, is a mental illness that impacts mood and how people act. Symptoms of depression can include feeling empty or hopeless, lack of energy, and loss of pleasure in activities that one used to find enjoyable. When people have depression, they experience persistent symptoms for at least two weeks or more.

T​o accurately diagnose depression, doctors will look a someone’s history, ask questions, evaluate symptoms, and work to rule out any underlying physical causes for symptoms.

Dr. Jhilam Biswas, director of the Psychiatry, Law and Society Program at Brigham and Women’s Hospital, Boston, Massachusetts, who was not involved in the study, explained to Medical News Today the challenges in diagnosing depression.

“Making a diagnosis of depression requires a full clinical evaluation complete with history taking, background information, a review of organ systems, and a targeted symptom checklist,” she said.

“Because each person has an individual way of presenting with depression, and the illness can look different from person to person, a complete evaluation is important so that symptoms can be treated appropriately.”
— Dr. Jhilam Biswas

One area of interest is the changes in speech patterns among people with depression. Researchers are working to understand these changes and how doctors can best study speech to identify people with mental illnesses.

Speaking to MNT, Dr. Krystina Patton, registered psychotherapist, who was not involved in the study, noted that speech can give clues to many different behaviors.

“Speech patterns can reveal so much about the internal state of the person talking. We automatically and intuitively infer the emotional flavor of what’s being said based on the speaker’s prosody. And it turns out that beyond providing helpful social cues, speech patterns can also be a useful tool in the diagnosis of mental health conditions.”
— Dr. Krystina Patton

This study specifically looked at depression indicators and speech patterns in a non-clinical sample. The authors note that they wanted “to test whether there would be an association between subtle signs of depression and speech features in a non-clinical population (i.e., in healthy young adults).”

Researchers included 118 young adults in their analysis. The mean age of the participants was about 24 years.

Each participant filled out a questionnaire that measured symptoms of depression. A higher score indicated a higher likelihood of depression.

Participants also completed a particular test called a trail-making test. This test measured participants’ ability to focus, process information, and switch between tasks. Participants that scored above the cut-off for clinically relevant depressive symptoms also took a longer amount of time to complete a portion of the trail-making test.

Researchers analyzed each participant’s speech by asking them to talk about one negative and one positive event. Participants spoke for one minute on each prompt, and researchers recorded their responses.

Upon data analysis, 25 participants scored above the cut-off of relevant depressive symptoms, and 93 scored below the cut-off. For the participants who scored higher for depression, researchers found that the group spoke more than those who scored lower for depressive symptoms.

Researchers were also able to accurately predict which group someone was in about 93% of the time.

The study authors note, “Our results indicate that even in a sample without a clinical diagnosis of depression, changes in speech relate to higher depression scores.”

D​r. Patton highlighted the study’s importance as a possible new predictive tool.

“This study raises the question as to whether speech patterns may also be a helpful predictive tool. None of the participants in this study were clinically depressed, and yet those with depressive symptoms showed marked differences in speech patterns than those without. It’s possible that such linguistic differences are indicative of the early stages of depression.”
— Dr. Krystina Patton

The study did have several limitations that are important to note.

First, the study only included university students, and 79% of recruited participants were women. These are not representative of the general population. This indicates that future studies can include more diverse samples.

Second, researchers only examined relatively short recordings of speech patterns, which can only capture so much information. Researchers also did not conduct clinical interviews for participants, so some participants may have been clinically diagnosed with depression.

However, based on the scores of depressive symptoms, this appears unlikely. Researchers note that long-term studies could work to see if the features they identified are early indicators of depression.

T​he findings of this study indicate the need for further research into speech patterns and depression.

Dr. Patton noted how this research could be helpful in the future:

“While further research is needed to confirm this, should it be true, then such subtle changes in speech patterns may be a useful screening tool in early detection of depressive processes, helping to identify those who are at risk for major depression in the future.”

The main finding from the study that people with higher indicators of depression talked more is the opposite of what is typically seen in people with depression.

Researchers noted a few explanations for this, including that perhaps people with earlier signs of depression may initially talk more, and then the number of words may decline.

David Tzall, a licensed psychologist who was also not involved in the study, speculated as to the reason for this particular finding:

“Those with higher depression may talk more because they are experiencing feelings of loneliness and isolation. Talking may be a way to connect with others. Since this is a non-clinical population, it makes sense that a healthy group would use communication strategies when they feel down.”

“Talking more can be a way to express feelings and to find support and understanding. Individuals may use talking as a coping mechanism to distract themselves from their negative thoughts and emotions.”
— David Tzall, psychologist