He says depression is better described as a brain-body disorder that involves peripheral systems – ie the bits of our bodies that send signals back to the brain.
Emotions, thoughtÂ and behaviour arise not just from the activity of brain circuitry, but also from sensory-motor experiences of our external environment – what researchers callÂ ’embodied cognition’.
â€œthe brain is not the sole cognitive resource we have available to us to solve problems. Our bodies and their perceptually guided motions through the world do much of the work required to achieve our goals, replacing the need for complex internal mental representationsâ€ (Wilson and Golonka)
That last bit sounds encouraging; no more complex internal mental representations needed to understand why we can’t even get out of bed!
Too hot to handle (life)
NowÂ consider thatÂ depressionÂ is associated with raised body temperature and disruption to the circadian rhythm that governsÂ changes in body temperature throughout the 24h cycle.
It turns out that serotonin plays a big part in regulating body temperature, by being involved in sending messages from the body to brain to turn the heat down or up.
Raison and his colleagues are exploring whether the release of serotonin in the brain that is associated with thermoregulation also has an antidepressant effect. And that does seem to be the case.
Their research involves putting depressed people in a hyperthermia chamber and heating it to about 60C (140F).Â Heat toÂ the skin in this way seems to activate a very specific neural pathway that causes the body to cool (by sort of kicking the body’s thermostat into action) butÂ also to reduce depression symptoms.
Â “Maybe some people are depressed not just totally because of their brain â€“ maybe it’s in their skin; their skin is sending some wrong signal to the brain,” Charles Raison
In this video, Raison explains his thinking, and makes mention of time-honoured human practices of using saunas and sweat lodges (and more recent hot yoga).
Soaking in a really hot bath is one of the things that make me feel better. I wonder if the reason is Raison’s. To be investigated further.
Embodied cognition is not what you think it is, AD Wilson and S Golonka (2013)
Time and depression: when the internal clock does not work, G Hajak and M Landgreber (2010)