Last month I wrote about a recent study suggesting it may be hard to think your way out of depression. I warned readers not to let such results stop us from watching how we think, and perhaps avoiding depression in the first place.
As a further note-to-self to watch those thoughts, consider another thought-ful study.
Here’s what the study did.
- People were given tests of negative thinking to identify their risk of developing depression. People in the top quarter of scores were put in a high-risk group and people in the bottom quarter were put in a low-risk group. Currently depressed people were excused from the study.
- Participants’ mental health was assessed regularly over 2.5 years*. The assessors didn’t know which people were in which group.
Here’s what the study found.
- Whether or not people had a history of depression, a greater proportion of the high-risk group than the low-risk group developed both major depressive disorder (the clinical term for depression) and minor depression.
- For people with no history of depression, 17% of the high-risk group, compared with only 1% of the low-risk group, developed major depressive disorder. The high-risk group also had many more minor depressive episodes.
- The researchers concluded that negative thinking makes you more susceptible to depression.
Some studies look at the relationship between negative thinking and depression at a snapshot in time. But knowing things go together doesn’t say which came first – do you think negatively because you’re depressed or are you depressed because you think negatively? Because this study unfolded over time and excluded already-depressed people, it could say that depression followed thinking.
That doesn’t prove negative thinking causes depression, but it’s good evidence that negative thinking could be a contributor.
So please – watch what you think. It’s powerful.
Study details: Alloy L.B., Abramson L.Y., Whitehouse W.G., Hogan M.E., Tashman N.A., Steinberg D.L., Rose D.T., & Donovan P. (1999). Depressogenic cognitive styles: predictive validity, information processing and personality characteristics, and developmental origins. Behaviour Research and Therapy, 37, 503-531(29).
*The study was part of a series for which data was collected over 5 years. The results described here apply to the first 2.5 years of the data.