Apathy

A lack of interest or the attitude of indifference towards life, including social or emotional situations. See also anomie, acedia, and ennui.

Reference:

Mann, R. S. (1990). Differential diagnosis and classification of apathy. American Journal of Psychiatry, 147(1), 22-30. https://doi.org/10.1176/ajp.147.1.22

Starkstein, S. E. (2000). Apathy and withdrawal. International Psychogeriatrics, 12(S1), 135-137. https://doi.org/10.1017/S1041610200006918