What is the interpretation of the cyclical change in the father's behavior, from a normal state to nervousness, delusions, and suspicions, then a return to his natural state after treatment, and does this indicate jinn or sorcery?

What afflicts the father may be an undiagnosed physical illness, or possession by jinn, or magic. The questioner should turn to Allah in supplication for her father and recite the Islamic ruqyah upon him, while maintaining the morning and evening remembrances, Ayat al-Kursi, and Surahs Al-Ikhlas and Al-Mu'awwidhatayn after prayers and before sleeping, and reading the last two verses of Surat Al-Baqarah every night.