Why treating frown lines could help depression

BOTOX is being tested as a treatment for depression. Around 50 people aged 65 or over will have forehead injections of the toxin, or a placebo, to test its effects.

The idea is based on the feedback theory — which proposes that our facial expressions influence our emotions, as well as reflecting them, so stopping movement of the muscles used in frowning will alleviate depression.

The researchers, of Norway’s Stavanger University Hospital, say some patients don’t respond well to the existing treatments, which tend to be associated with side-effects, whereas the toxin jabs are considered very safe.