Struggle: Angelina Jolie has disappeared from public view since the birth of her twins in July and is said to be in 'depression mode'

Angelina Jolie is struggling to cope following the birth of her two-month-old twins Vivienne and Knox, according to new reports.

The mother of six has been holed up at the Château Miraval in Provence, France, since the birth and has not been seen save for a family photo shoot last month.

Sources claim the Lara Croft star is exhausted by the sleepless nights and has called in doctors over concerns for her newborns' health.

The babies are said by the National Enquirer to be suffering from colic, a common but largely unexplained condition that causes repeated episodes of excessive and inconsolable crying.

Meanwhile insiders told America's In Touch magazine that their constant state of distress has caused Angelina to slip into 'depression mode', prompting fears she may be suffering post-natal depression.

'The 33-year-old 'has been trying to control her emotions' around her older children Maddox, 7, Pax, 4, Zahara, 3, and Shiloh, 2, but 'her mood swings have been hard on the entire family,' according to the source.

'She has been staying in bed most of the time, all she does is sleep. She has little energy and has to force herself to remember to eat because she is still breast feeding.

'She cries at the drop of a hat and laughs at inappropriate times.'

'Brad has it easy': The actor jetted off to Italy with sons Pax and Maddox last month while Angelina stayed in France with the rest of their brood

Revelations: The issue of In Touch

And the insider adds: 'Everyone around her is hoping that she will talk to someone about how she is feeling.'

It has also reportedly put a strain on her relationship with Brad Pitt, who visited Italy last month with Maddox and Pax for the Venice Film Festival.

'Angelina feels that Brad has it easy,' says the source.

'He had the kids without the pain of birth, and he can just jet off whenever he feels like it.'

Despite Angelina's struggle, Brad is already planning more children, telling reporters in Venice: 'I'll have two more by next year.'