For many, the dark thoughts of depression are accompanied by perceptual sensations

The assessment and treatment of depression usually deals with negative verbal thoughts as if they are distinct from negative mental imagery and perceptual sensations. A new study led by Steffen Moritz at the University of Hamburg suggests this is a mistake – many people with depression report that their negative thoughts have a sensory quality. What's more, experiencing depressive thoughts with perceptual sensations tends to go hand in hand with more serious depressive illness.

Recruited via hospitals, insurance companies and online forums, 356 people with mild to moderate depression were surveyed online (people meeting diagnostic criteria for psychosis or bipolar disorder were excluded). Among the survey questions, participants were asked if their depressive thoughts were ever accompanied by sensations. An example would be the sense that an "inner critic" has an actual voice. Another would be thinking about a feared catastrophe and actually seeing it take place in the mind's eye.

Fifty-seven per cent of the sample reported that their depressive thoughts are sometimes accompanied by sensory properties. Most often (40 per cent of the time) they said these were bodily; less often they were auditory (31 per cent) or visual (27 per cent). The sensory experiences were mostly described as weak and medium intensity. Importantly, the people who reported experiencing sensory qualities to their depressive thoughts tended to have had more depressive episodes, and to have been hospitalised with depression more frequently in the past.

Moritz and his team said this was a neglected area and that their findings needed replication. If confirmed by future research, they believe "vivid sensory colouring of negative thoughts may … be regarded as a common phenomenon affecting half of depressed patients. It follows that rather than focusing solely on verbal content, sensory properties of thoughts warrant greater consideration in depression."

In particular, the researchers recommended that it could help to include questions about the sensory properties of depressive thoughts in future versions of depression rating scales (currently such phenomena are often overlooked). The results also have implications for the treatment of depression. Current approaches typically target verbal thoughts without considering their sensory sequelae. Moritz and his team suggested that "a potential vulnerability factor" could be turned into "an asset by using vivid mental imagery in a positive way" – for example, by encouraging depressed people to relive positive memories or imagine positive outcomes.

Further reading

Moritz S, Hörmann CC, Schröder J, Berger T, Jacob GA, Meyer B, Holmes EA, Späth C, Hautzinger M, Lutz W, Rose M, & Klein JP (2014). Beyond words: Sensory properties of depressive thoughts. Cognition and Emotion PMID: 24359124