This is in agreement with the Bible, which says: “A joyful heart is good medicine. ”
(‏ ام ١٧ :‏ ٢٢‏ )‏ وَهٰذَا مَا ذَكَرَهُ أَيْضًا بَاحِثٌ فِي مَجَالِ ٱلصِّحَّةِ مِنْ جَامِعَةِ نِبْرَاسْكَا ٱلْأَمِيرْكِيَّةِ .‏