The oldest son of late Cuban leader Fidel Castro committed suicide on Thursday after months of treatment for depression, state media reported. He was 68.

According to the state media, Fidel Castro Diaz-Balart had been in a "deeply depressed state."

"I have the painful task to announce to our country that our comrade, Fidel Castro Diaz-Balart has died. A doctor of science, Fidel Angel Castro Diaz-Balart, who was being cared for by a group of doctors for a number of months, due to a case of severe depression, took his own life this morning, today the 1st of February,” Arlene Rodriguez, Cuban television news anchor, said. 

A brief note read on state television said his treatment had "required a hospitalization regime then outpatient follow-up", the Associated Press reported. 

The eldest son of Cuba's former leader was known for his distinctive beard and resemblance to his father, earning him the nickname Fidelito or Little Fidel.

Castro Diaz-Balart had served as scientific adviser to the Council of State and was vice president of the Cuban Academy of Sciences, the report said.

According to AP, his mother was Mirta Diaz-Balart, a woman from Cuba's aristocracy who Castro married in his youth before beginning the revolutionary struggle that later brought him and his brother Raul to power.