HAVANA (Reuters) - The eldest son of late Cuban revolutionary leader Fidel Castro, Fidel Castro Diaz-Balart, committed suicide on Thursday aged 68 after being treated for months for depression, Cuban state-run media reported. 
 
 The nuclear scientist, also known as “Fidelito”, or Little Fidel, because of how much he looked like his father, had initially been hospitalized and then continued treatment as an outpatient. 
 
 “Castro Diaz-Balart, who had been attended by a group of doctors for several months due to a state of profound depression, committed suicide this morning,” Cubadebate website said. 
 
 Fidelito, who had the highest public profile of all Castro’s children, was born in 1949 out of his brief marriage to Mirta Diaz-Balart before he went on to topple a U.S.-backed dictator and build a communist-run state on the doorstep of the United States during the Cold War. 
 
 Through his mother, Castro Diaz-Balart was the cousin of some of Castro’s most bitter enemies in the Cuban American exile community, U.S. Representative Mario Diaz-Balart and former U.S. congressman Lincoln Diaz-Balart. 
 
 He was also the subject of a dramatic custody dispute between the two families as a child. 
 
 Cuba scholars say his mother took him with her to the United States when he was aged five after announcing she wanted a divorce from Castro, while he was imprisoned for an attack on the Moncada military barracks in Santiago. 
 
 Castro was able to bring Fidelito back to Cuba after the 1959 revolution. 
 
 A multilingual nuclear physicist who studied in the former Soviet Union, Castro Diaz-Balart was head of Cuba’s national nuclear program from 1980 to 1992, and spearheaded the development of a nuclear plant on the Caribbean’s largest island until his father fired him. 
 
 FILE PHOTO: Fidel Castro Diaz-Balart, son of Cuba's President Fidel Castro, talks to Argentine human right activist and member of the Mothers of the Plaza de Mayo group Hebe de Bonafini during the inauguration of the International Book Fair in Havana February 8, 2007. REUTERS/Claudia Daut/File Photo 
 
 Cuba halted its plant plans that same year because of a lack of funding after the collapse of Cuba’s trade and aid ties with the ex-Soviet bloc and he largely disappeared from public view appearing at the occasional scientific conference or diplomatic event. 
 
 Fidelito had been working for his uncle President Raul Castro as a scientific counselor to the Cuban Council of State and Vice-president of the Cuban Academy of Sciences at the time of his death. 
 
 A former British ambassador to Cuba, Paul Hare, who lectures at Boston University’s Pardee School of Global Studies, said Castro Diaz-Balart had seemed “thoughtful, rather curious about the world beyond Cuba” at a dinner in Boston two years ago. 
 
 “But he seemed a bit weary about having to be a Castro, rather than himself,” Hare said. 
 
 Jonathan Benjamin-Alvarado, a Cuba expert at the University of Nebraska in Omaha, said Fidelito had provided him with invaluable help in the 1990s while he was writing a book on Cuba’s nuclear program. 
 
 In 2000 they met again at a conference in Moscow and Fidelito worked “the room full of international nonproliferation experts, diplomats and journalists with aplomb, speaking no less than four languages -Spanish, English, Russian and French.” 
 
 Benjamin-Alvarado said he suspected Fidelito’s title as scientific advisor was largely ceremonial as his views on energy development were not incorporated into national policies. 
 
 “He had written extensively on Cuba’s need for developing renewable energy resources,” Benjamin-Alvarado said. “And yet almost all efforts by the Cuban government were geared to maintaining the status quo of oil dependency.” 
 
 “I imagine that was disappointing for him.” 
 
 Fidelito’s death came just over a year after that of his father on Nov. 25, 2016, aged 90. 
 
 Slideshow (3 Images) ||||| Image copyright AFP Image caption "Fidelito" (right) lived in his famous father's shadow 
 
 The 68-year-old son of Cuba's former leader Fidel Castro has killed himself in Havana, according to Cuban state media. 
 
 Fidel Ángel Castro Díaz-Balart was found on Thursday morning and is said to have suffered from depression. 
 
 The first-born son of the late president was nicknamed "Fidelito", or Little Fidel, after his father. 
 
 He was a nuclear physicist, trained by the former Soviet Union. 
 
 "Fidel Castro Díaz-Balart, who had been treated by a group of doctors for several months due to deep depression, took his life this morning," Cuba's official newspaper Granma reported - little more than a year after the death of his father. 
 
 State television said he had been receiving medical treatment as an outpatient in recent months, following a hospital stay. 
 
 Depression in the spotlight - Will Grant, BBC News, Havana 
 
 Image copyright AFP Image caption Fidelito's work for the Cuban regime came to an end with the collapse of the Soviet Union 
 
 Fidel Ángel Castro Díaz-Balart had taken his own life after suffering with deep depression which doctors had been treating him for over several months, state TV said. 
 
 As much as the death itself may shock ordinary Cubans, it was those unexpected circumstances which caught them by surprise. 
 
 As the personal lives of members of the Castro family are generally kept away from the public eye, almost no-one will have known he suffered mental health issues prior to the announcement of his death. 
 
 Did Fidel Castro's name kill his son? 
 
 At the time of his death, he was a scientific adviser for the Cuban Council of State and he served as vice president of Cuba's Academy of Sciences. 
 
 He headed the island's nuclear programme from 1980 to 1992, before it was suspended after the Soviet Union's collapse. 
 
 He was married to María Victoria Barreiro and had three children from his previous marriage - Fidel Antonio Castro Smirnov, Mirta María Castro Smirnova and Jos­é Raúl Castro Smirnov. 
 
 Image copyright AFP Image caption Fidel Ángel Castro Díaz-Balart (centre) attends a ceremony with his father's ashes in an urn in December 2016, days after the elder Fidel's funeral 
 
 Image copyright Reuters Image caption Fidel Ángel Castro Díaz-Balart poses with socialite Paris Hilton during the Habanos Festival in Havana in 2015 
 
 Fidel Castro Díaz-Balart was born in 1949, during his father's brief first marriage to Mirta Díaz-Balart, the daughter of a prominent pre-revolution politician. 
 
 His father went on to overthrow the US-backed dictator, Fulgencio Batista, in 1959 - when his mother's family fled the island and went to Florida. 
 
 His parents divorced and "Fidelito" spent some of his early years in the US before his father managed to bring him back to Cuba. 
 
 This history explains why some of his close maternal relatives are among the most committed critics of the Cuban government - such as his cousin, Mario Díaz-Balart, a US congressman. 
 
 Fidelito himself was loyal to the ideals of the Cuban revolution, but was said in recent years to have grown weary - both of living in his father's shadow and having been sidelined from Cuban decision-making on energy resources, said reports. 
 
 His ideas for developing renewable energy on the island were not incorporated into state policy, an academic colleague, Jonathan Benjamin-Alvarado, told Reuters. 
 
 "I imagine that was disappointing for him," Mr Benjamin-Alvarado said. 
 
 The TV announcement said his funeral would be planned by his family, but no further details were given. 
 
 His father, Fidel Castro, a revolutionary figure and one of the world's longest serving political leaders, died aged 90 in 2016.
– The eldest son of former Cuban leader Fidel Castro has taken his own life after months of being treated for "profound depression," according to state-run media in Cuba. Fidel Castro Diaz-Balart, nicknamed "Fidelito," was 68. Castro-Diaz Balart, who was born during Castro's brief, pre-Cuban Revolution marriage to Mirta Diaz-Balart, headed Cuba's national nuclear program from 1980 to 1992 and was serving as a scientific adviser for the Cuban Council of State at the time of his death, Reuters reports. Castro Diaz-Balart was born in 1949. His mother took him to live in the US after she divorced Castro in 1953. She sent him to visit his father after he took power in 1959 and he never returned him, CNN reports. Castro Diaz-Balart trained as a nuclear physicist in the Soviet Union and spoke Russian, Spanish, English, and French fluently. Paul Hare, a former British ambassador to Cuba, tells Reuters that Castro Diaz-Balart seemed "thoughtful, rather curious about the world beyond Cuba" when he met him at a dinner in Boston two years ago. "But he seemed a bit weary about having to be a Castro, rather than himself," Hare says. The BBC reports that he was related on his mother's side to prominent anti-Castro regime politicians in the US, including his cousin, Republican Rep. Mario Diaz-Balart. (Fidel Castro died 14 months ago at 90.)