MIAMI — They called him “Fidelito” — little Fidel — partly because he was the spitting image of his father, Fidel Castro, the late Cuban revolutionary.

But that’s where the similarities ended.

Fidel Castro Diaz-Balart, the Cuban leader’s son from his first marriage, took his own life after a struggle with depression, Cuba’s state media reported on Thursday. He was 68.

The bookish, Russian-educated scientist maintained a complicated relationship with his father — who once publicly fired him.

The product of his father’s marriage to Mirta Diaz-Balart, Fidelito was a symbol of the complexities of the Cuban experience after the revolution. After an acrimonious divorce from Fidelito’s father, she took him temporarily to the land of Yankee imperialism — the United States. During the boy’s visit to his father in Mexico, where Castro was planning his revolution, he kept his son, prompting his mother to hire kidnappers who eventually got him back.

“I refuse even to think that my son may sleep a single night under the same roof sheltering my most repulsive enemies and receive on his innocent cheeks the kisses of those miserable Judases,” the elder Castro wrote in a letter to his sister.

Later, after Castro remarried, Fidelito became but one more in a large brood of Castro children — who number at least seven  and as many as 11. Fidelito was also the cousin of the fiercely anti-communist Florida politicians Rep. Mario Diaz-Balart (R) and former congressman Lincoln Diaz-Balart (R).

Fidelito’s most public moment was also perhaps his worst.

In the 1980s, the elder Castro, who died in 2016, had tapped his son to spearhead Cuba’s nuclear power program. His brainchild: the Juragua Nuclear Power Plant, a Russian-backed complex meant to proudly power the communist island and provide a boost during hard economic times. Fidelito suddenly seemed destined for greatness.

Those dreams came crashing down along with the Berlin Wall. The Soviet Union’s implosion robbed Cuba, for a time, of its greatest benefactor. At the same time, insurmountable technical and financial problems doomed the plant — which became an abandoned Cold War relic. The elder Castro publicly blamed his son, whom he unceremoniously fired in 1992.

“There was no resignation,” Castro declared at the time, according to Ann Louise Bardach’s book “Without Fidel.” “He was fired for incompetence. We don’t have a monarchy here.”

Though Fidelito would later win new appointments — at the time of his death, he was scientific adviser to Cuba’s Council of State and vice president of the Academy of Sciences of Cuba — he never quite bounced back. Few considered him a serious player in the island’s politics, now ruled by his uncle, Raúl Castro, who is set to step down in April.

Fidelito was never viewed, experts say, as a potential replacement.

“He had some physical resemblance to Fidel, but that was it,” said Arturo Lopez-Levy, a former Cuban government analyst who is now a professor of political science at University of Texas Rio Grande Valley.  “He was never associated with the charisma that his father had.” Fidel Castro Diaz-Balart in 2012. (Franklin Reyes/AP)

Granma, Cuba’s official Communist Party news service, published a five-paragraph announcement, noting that Fidelito had undergone months of treatment for depression, including a period of hospitalization. He was an outpatient when he died Thursday morning.

The manner of his suicide was not disclosed.

“During his professional life, he was dedicated entirely to the sciences, and obtained important national and international recognitions,” the outlet said.