How you reorder sentences can predict recurrence of depression, study shows
Oct. 18, 2010
When word got out that actor Owen Wilson, best known for his comedic roles, had tried to commit suicide and suffered from depression, people were stunned.
Who would have thought? He seemed fine. For that matter, he seemed on top of the world.
No matter how many times we hear glitterati like Terry Bradshaw, Drew Carey and Halle Berry admit to suffering from depression, we're still amazed that it can so artfully and successfully be concealed. Truth is, a lot of the time the disease is even hidden from the person who has it.
Since a person may have depressive thoughts and not recognize them as such — thinking that's how "normal" should feel — mental health professionals and researchers can have kind of a hard row to hoe when it comes to identifying who's vulnerable to the disease.
In the past, efforts to predict the likelihood of future depressions depended on questionnaires or surveys that a person filled out, or "self-report measures." For the questionnaires to be of any use, a patient needed to be willing to answer tough questions frankly and to have enough self-awareness to assess mental and emotional states pretty accurately. The only problem is that these surveys too frequently missed the at-risk people.
University of Texas at Austin educational psychologist Stephanie Rude has done research that yields a solution to that problem through the use of a deceptively simple-looking word exercise. To appreciate just how much her discovery means, though, you need to know a little bit about how the brain works and how depression can go into hiding but not disappear.
"Identifying vulnerability to depression can be challenging because there's more going on than what an individual is explicitly aware of," says Rude, a professor in the College of Education's Department of Educational Psychology. "We believe automatic thought processes that are inaccessible to conscious reflection contribute to the development and maintenance of depressive disorders. Someone can have subtle negative 'schemas' — depressive ways of understanding the world — but consider himself, or at least describe himself, as a person who thinks relatively positively."
In her research, Rude takes a cognitive approach, and the informing feature of cognitive theories of depression is that feelings and behaviors are driven not only by external stimuli like people, situations and events, but also by the way we make sense of these events. Biases in the way we perceive, interpret, and remember information play a big role in our susceptibility to depression.
"It's well established that depressed people tend to focus their attention on unhappy and unflattering information, interpret information negatively and hold generally pessimistic beliefs," says Rude. "An important claim of cognitive models of depression is that these negative modes of thinking are not only symptoms of depression; they also function as causal antecedents of depression. Routinely thinking things like, 'There's no point in applying for that job because I'd never get it', or assuming that friends or loved ones don't really care, can contribute to becoming depressed."
One of the ways researchers learn more about the effects of negative thinking styles is to study people who have a history of depression.
It's an alarming statistic, but research shows that people who have one episode of depression have around a 50 percent chance of having another. According to cognitive theories of depression, one reason for the high rate of recurrence is that pervasive, subtle, negative mental scripts can still be running under the conscious radar after recovery and can make a person vulnerable to another bout of Major Depressive Disorder (MDD).
According to Rude, these negative modes of thinking aren't usually very difficult to detect in people who are in the midst of a depression.
"It's when the depression-vulnerable person has recovered from depression that the biases become elusive and difficult to assess," she says. "When they recover from depression, people's self-reported beliefs and thinking styles tend to look normal. Research shows, though, that events that bring on a sad mood catapult many of the recovered back into a dim and pessimistic view of the world. We don't see the same thinking changes in those without a history of depression when they feel sad. The notion is that a depressive cognitive style is what can make an otherwise passing sad mood develop into an episode of Major Depressive Disorder."
To get past the problem of having to rely solely on self-reporting of cognitive biases, Rude has used a tool developed by Richard M. Wenzlaff called the Scrambled Sentences Test (SST). It can be administered in conjunction with self-report questionnaires and seems to possess a unique sensitivity to biases in thinking that signal vulnerability to depression.
"The Scrambled Sentences Test allows us to observe firsthand how patients interpret a particular set of ambiguous information," says Rude, "as opposed to asking them to report to us, via a questionnaire or survey, how they do this. In this way it seems to tap more directly into the schemas and dysfunctional beliefs that are characteristic of depressive thinking and to bypass some of the distortions that arise from inaccurate self perceptions or attempts to 'look healthy.'"
The SST requires participants to create coherent sentences from scrambled phrases like "winner born I am loser a." How the participant unscrambles the words can reveal whether she tends to interpret ambiguous information in an upbeat way or an unflattering and pessimistic way. Those suffering from depression are more likely to unscramble the words to create a negative sentence like "I am a born loser," while non-depressed people typically unscramble the words to create a sentence like "I am a born winner."
Early research by Wenzlaff, Rude and their colleagues found that recovered depressed people also will come up with more negative solutions than the never depressed, but only if they've been given a "cognitive load," like a six-digit number they have to keep in mind while doing the task.
Rude's research findings are so significant because they demonstrate how these dysfunctional thoughts and beliefs, and their relationship to MDD, play out over time. In several studies, Rude has shown that performance on the SST can predict the occurrence of Major Depressive Disorder months, or even years, later.
In a study of hers that was published this year, participants were given two sets of 25 scrambled sentences and had three and a half minutes to unscramble each set. In order to prevent participants from strategically framing their responses or suppressing negative phrases, they were required to keep a six-digit number in mind while unscrambling one of the sentence sets.
Over a follow-up period of up to 30 months, Rude and her colleagues conducted diagnostic interviews to see if participants had developed MDD.
"I wanted to determine if these observed cognitive biases, as measured by the SST, play a role in the recurrence of depressive disorders," says Rude. "Showing that performance on the SST is predictive of future depressive episodes offers crucial support for the claim that cognitive biases play a causal role in depression."
In the study, Rude found that the SST was indeed a significant predictor of subsequent depressive disorders. Participants who unscrambled a higher proportion of sentences to form negative statements on the SST were more likely to be diagnosed with depression at follow up.
"Interestingly, and consistent with prior findings, only the subset of sentences that had been completed under cognitive load predicted a later diagnosis of depression," says Rude. "This supports the idea that a truer picture of the cognitive biases contributing to depression vulnerability emerges when respondents' ability to intentionally compose their answers is hindered."
Another interesting aspect of her study was that the SST showed an advantage in the prediction of subsequent depression over and above the Dysfunctional Attitudes Survey (DAS), a widely used self-report questionnaire.
"These results are exciting, both for their theoretical implications — which is to say, the support they provide that cognitive biases play a role in bringing about depression — and for the promise of practical applications," says Rude. "Anything that can help us predict or catch the onset of depression early and begin to treat it is a good thing. And if we use both types of measurement — self-report as well as non self-report — I think we'll enhance our theoretical understanding by shedding light on the specific types of cognitive processes that contribute to depression vulnerability."
So, if you've had depression before, the question is not so much, "Are you depressed now?" as "winner born I am loser a"?