"Delivering fundamental and permanent change will require a focus and a genuine commitment on the part of the leadership of the House," the report notes.
"However, the inescapable conclusion from the views expressed during this inquiry is that it will be extremely difficult to build confidence that there will be fundamental change when the levers of change are regarded as part of the change that is needed," it said.
In the 155-page report, Cox quoted several anonymous contributors who said it would take "several generations" for meaningful change to be enacted.
"On this basis, I find it difficult to envisage how the necessary changes can be successfully delivered, and the confidence of the staff restored, under the current senior House administration," she said.
She added: "When reading this report some people may privately recognise their own behaviours in some of the alleged abusive conduct I have described.
"I would hope that a process of reflection leads them to consider what, if anything, they should now do in the best interests of the House."
The terms of reference of the report meant that she was unable to name the individuals against whom "serious allegations of abusive conduct" had been made, but there is growing pressure on House of Commons Speaker John Bercow to step down as one of those accused of bullying by Commons staff allegations that he denies.
Some of the "disturbing" behaviour flagged in the new report include MPs shouting at and belittling staff; swearing at them face to face and treating them like "servants"; and women always being asked to buy the coffee or make the tea and asked why they needed to work or have a career if they had a husband.
Some ethnic minority staff reported racist abuse and being frequently challenged as to their right to be in particular parts of the building and staff reported being told not to raise complaints as it would be bad for their careers.
Besides, women reported harassment in the form of comments about their appearance, their dress or their "physical attributes", frequent inappropriate touching and being repeatedly propositioned.
The report warned the "collective reputation" of Britain's MPs was being damaged by the allegations against a small number.
In a statement, the House of Commons said: "Bullying and harassment have no place in the House of Commons, and the well-being of our people will always be our top priority.
"Staff must be confident that unacceptable behaviour will be dealt with seriously, independently and with effective sanctions. Urgent work has already been undertaken to improve internal processes including the introduction of new confidential support services and helplines run by external, independent specialist providers and a clear pathway for the investigation of allegations.
The report follows what was seen as a part of Britain's "Me Too" movement earlier this year, when numerous people working within Parliament had spoken out about a culture of bullying and harassment.