FIGURE 13-10 Dysfunctional Clock? Attacks of mental illness displayed by the English writer Mary Lamb through her adult life appear to have had a cyclical component. Such observations would be difficult to obtain today because the drugs used to treat psychiatric disorders can mask disordered biorhythms.

Information from C. P. Richter (1965). Biological clocks in medicine and psychiatry (p. 92). Springfield IL: Charles C Thomas.