Abstract

Objective: A novel technique for the kinematic analysis of emotionally induced facial expressions was applied to detect subtle mimic dysfunction in patients with depression.

Methods: Using ultrasound markers at certain points on the face, facial movements were exactly measured while subjects watched a witty sketch (“Mr Bean”). Twenty five medicated patients with depression (11 men, 14 women; mean age, 55.8 years; mean total Hamilton Depression Rating Scale score, 17.1) and 25 healthy controls, matched by sex distribution and handedness, were studied.

Results: Depressed patients were characterised by abnormally slow velocity at the beginning of laughing and voluntary facial movements, in addition to reduced laughing frequency. A higher severity of symptoms of depression was significantly associated with slow initial velocity of laughing movements of the left mouth angle (r  =  −0.45).

Conclusion: The execution of voluntary and non-voluntary facial movements is abnormally slow in depressed patients, reflecting hypomimia. This mimic slowing is closely associated with the severity of depression. The response of depressed patients to emotional stimuli is also abnormally low, but emotional estimation of the stimuli is similar to normals. This pattern parallels the motor–emotional features known from patients with Parkinson’s disease.