Most of us are familiar with the extraordinary book The Anatomy Of An Illness by Norman Cousins (1979). In it he describes the therapeutic benefits of laughter. Cousins had crippling arthritis and was told, pretty much, it was incurable.
Well, it wasn’t! Norman Cousins checked out a whole bunch of old movies (Marx Brothers, Candid Camera Episodes, The Three Stooges, Laurel and Hardy, etc.) and laughed his head off for weeks and months.