Davenport S, Goldberg D, Millar T
Lancet. 1987 Aug 22;2(8556):439-41. doi: 10.1016/s0140-6736(87)90970-6.
There is a strong correlation between patients' scores on a psychiatric screening questionnaire and the number of cues indicative of psychological disturbance that patients give during the medical interview. Verbal cues have the strongest correlation with psychological distress as measured by the questionnaire, but movement cues and postural cues are also important. The reason why some doctors are better able than others to detect psychiatric illness is that they are more likely to allow patients to express verbal and vocal cues.