The 'Keeping Up with the Kardashians' star, who is rumoured to be battling a number of issues, including depression, after gaining 50 pounds, allegedly started spiralling out of control when his sister Khloé Kardashian's estranged husband moved out of the home the trio shared in Tarzana, California last year, amid rumours he had a drug problem and was cheating on Khloé.
A source told gossip website TMZ.com that the 27-year-old star went into a tailspin because he idolised the 34-year-old basketball player and thought Lamar was the only person who measured up to his late father, Robert Kardashian, who died of cancer in 2003.
The insider said that Rob has never really got over his dad's death, but thrived when he moved in with Khloé and Lamar after they got married in 2009, as the athlete inspired him to stay fit and start his own sock company.
Khloé, who filed for divorce from Lamar in December, admitted on her family's reality TV series that Rob's troubles were triggered by the ''dark things'' that happened in her former marital home.
Discussing the matter in a a clip for the next episode, she said: ''Rob has said, '[Living with Khloé and Lamar] was so dark and it made me do dark things.' ''
She added: ''Only Rob and Lamar and I know what went on in that house. I'm a nurturer and I want to protect everyone. I wasn't there to protect Rob. I wasn't even there to protect myself. No one can make me not feel guilty.''
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