Rob Kardashian has commenced "very intense therapy" sessions at the urging of older sister Kim.

Radar Online reports the only male of six Kardashian/Jenner siblings is rumored to be "slowly coming out of his shell" after a deep bout of depression that has contributed to his persistent weight gain. Sources add his new outlook on life is due in a great part to all his sisters' dedication.

"Rob has been doing very intense therapy at home," a source added. A second source later opined, "He doesn't ever want to work a program. None of them can work a 12 Step program, or anything public because it would hardly be anonymous."

Reports are, after Rob was more or less forced to miss several major family events, like younger sister Kylie's recent 18th birthday celebration, his sisters came together to urge him to do all he can to be able to reenter society on his own terms.

"The Kardashian girls are intent on helping Rob lose weight, because they believe his image issue is at the center of his other personal struggles," a source added.

And for the first time in what seems like forever, sources hint that Rob finally seems committed to improving his own physical condition.

"He is intent on beating this through working out and/or whatever is necessary," said a source.

Fueled by his sisters' commitment to spend extra time with him, reports are Rob is feeling a renewed sense of responsibility to his family.

"He wants to be the brother that was able to take care of his sisters like he promised his father he would before he died," a source added. "Now that they do not have Bruce because Bruce is definitely Caitlyn, Rob needs to step up to the plate."