How depression also affects people on a linguistic level

From the way you move and sleep to the way you interact with the people around you, depression changes just about everything. It’s even evident in the way you speak and express yourself in writing. Sometimes this language of depression can have a powerful effect on others. Just consider the impact of the poems and song lyrics of Sylvia Plath and Kurt Cobain, both of whom committed suicide after suffering from depression.

Scientists have long sought to establish the exact relationship between depression and speech, and technology is helping us get closer to the full picture. Our new study, published in Clinical Psychological Scienceshas now unveiled a class of words that can help accurately predict whether someone is suffering from depression.

Traditionally, linguistic analyzes in this field have been done by reading and note-taking researchers. Nowadays, computerized methods of text analysis make it possible to process very large databases in just a few minutes. This can help pinpoint linguistic features that humans may be missing by calculating the percentage prevalence of words and word classes, lexical diversity, average sentence length, grammatical patterns, and many other metrics.

So far, personal essays and journal entries from people with depression have been helpful, as have the work of well-known artists such as Cobain and Plath. For the spoken word, fragments of the natural language of people with depression also provided information. Taken together, the findings of that research reveal clear and consistent differences in language between those with and without symptoms of depression.

Content

Language can be separated into two components: content and style. Content refers to what we express, i.e. the meaning or subject matter of statements. It will come as no surprise to learn that those with symptoms of depression use an excessive amount of words that convey negative emotions, especially negative adjectives and adverbs such as lonely, sad, or unhappy.

More interesting is the use of pronouns. Those with symptoms of depression use significantly more first-person singular pronouns such as me, myself, and I, and significantly fewer second- and third-person pronouns such as they, they, or she. This pattern of pronoun use suggests that people with depression are more self-focused and less connected with others. Researchers have reported that pronouns are actually more reliable at identifying depression than negative emotion words.

We know that rumination (dwelling on personal problems) and social isolation are common features of depression. However, we don’t know whether these results reflect differences in attention or thinking style. Does depression cause people to focus on themselves, or do people who focus on themselves experience symptoms of depression?

Style

Speech style refers to how we express ourselves rather than the content we express. Our lab recently conducted a big data text analysis of 64 different online mental health forums, surveying over 6,400 members. Absolutist words that convey absolute magnitudes or probabilities, such as always, nothing, or completely, have been found to be better indicators for mental health forums than pronouns or words about negative emotions.

From the beginning, we predicted that people with depression would have a more black and white view of the world and that this would show in their speaking style. Compared with 19 different control forums (for example, Mumsnet and StudentRoom), the prevalence of absolutist words is about 50% higher in anxiety and depression forums and about 80% higher in suicidal ideation forums.

The pronouns produced a similar distribution pattern as absolutist words in forums, but the effect was smaller. In contrast, negative emotion words were paradoxically less prevalent in suicidal ideation forums than in anxiety and depression forums.

Our research also included recovery forums, where members who feel like they’ve recovered from a depressive episode write positive and uplifting posts about their recovery. Here we found that negative emotion words were used at comparable levels to control forums, while positive emotion words were increased by approximately 70%. However, the prevalence of absolutist words remained significantly greater than that of controls but slightly lower than for anxiety and depression forums.

Basically, those who have previously had depressive symptoms are more likely to have them again. Thus, their increased tendency to absolutist thinking, even when there are currently no symptoms of depression, is a sign that may play a role in causing depressive episodes. The same effect is seen in the use of pronouns, but not for negative emotion words.

practical implications

Understanding the language of depression can help us understand how those with symptoms of depression think, but it also has practical implications. Researchers are combining automated text analysis with machine learning (computers that can learn from experience without being programmed) to classify a variety of mental health conditions from natural language text samples such as blog posts.

That classification is already surpassing that made by experienced therapists. Importantly, machine learning classification will only improve as more data is provided and more sophisticated algorithms are developed. This goes beyond looking at the broad patterns of absolutism, negativity, and pronouns already discussed. Work has begun on using computers to accurately identify increasingly specific subcategories of mental health problems such as perfectionism, self-esteem issues, and social anxiety.

That said, it is obviously possible to use language associated with depression without actually being depressed. Ultimately, it’s how you feel over time that determines whether you’re in pain. But since the World Health Organization estimates that more than 300 million people worldwide live with depression, an increase of more than 18% since 2005, having more tools available to detect the condition is certainly significant for improving health and prevent tragic suicides like those of Plath and Cobain.

This article was originally published in The Conversation by Mohammed Al-Mosaiwi at the University of Reading. Read the original article here.