Despair in the Hereafter as spiritual disease

يَـٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوا۟ لَا تَتَوَلَّوْا۟ قَوْمًا غَضِبَ ٱللَّهُ عَلَيْهِمْ قَدْ يَئِسُوا۟ مِنَ ٱلْـَٔاخِرَةِ كَمَا يَئِسَ ٱلْكُفَّارُ مِنْ أَصْحَـٰبِ ٱلْقُبُورِ

O you who have believed, do not make allies of a people with whom Allāh has become angry. They have despaired of [reward in] the Hereafter just as the disbelievers have despaired of [meeting] the companions [i.e., inhabitants] of the graves.