One in Four, the organisation which supports people who have experienced sexual violence, was forced to create a waiting list for its psychotherapy services last year due to demand.
Its 2020 annual report says many people sought support for the first time because Covid-19 restrictions led some survivors to experience panic attacks, flashbacks and suicidal thoughts.
One in Four's Clinical Director Julie Brown said the waiting list for survivors increased from 20 people in March to 98 people in December.
Due to demands on the service "outstripping its ability to supply", the organisation was forced to close the waiting list at the end of 2020.
The report acknowledges that funding was received from the child and family agency Tusla for a waiting list case manager to support and offer resourcing strategies to those on the list.
Many of the men and women who contacted the service were "desperate to find a way to get rid of the intrusive thoughts and feelings that had resurfaced from their childhoods".
CEO Maeve Lewis said 2020 has been a stark reminder that many survivors never reach out for support.
Familial abuse was the highest percentage of cases reported by One in Four clients at 22% - a similar figure to 2019.
The most significant increase was the number of abuse types described as "unknown" which means One in Four has not been informed of the clients relationship, if any, to the abuser.
In 2019, "unknown" stood at 15.4%. In 2020, that figure rose to 21.4%.
Like other organisations, One in Four had to close its offices in March 2020 and find ways to provide services online.
It supported 172 clients through online individual and group psychotherapy.
The organisation also worked with 53 sex offenders in individual and group settings.
Ms Lewis pointed out that some of those attending the programme are online offenders, viewing child abuse material on the internet.
Therefore, transitioning to an online service for this group required careful consideration, but it was managed successfully.
The report also notes that the pandemic has led to delays in Jury trials.
Many were put back to 2021 or listed for 2022 due to the pandemic which has caused frustration and further upset for complainants according to the report.
Just three clients were supported by One in Four at trial in 2020.
The Ombudsman for Children Dr Niall Muldoon has said the psychotherapy waiting lists for survivors of child sexual abuse "is a real negative impact of Covid" and they need to get through this waiting list as quickly as possible.
Speaking on RTÉ's News at One, Dr Muldoon said the impact of these delays is huge.
He said "if you're a survivor of sexual abuse and you're waiting for your therapeutic input, you're hoping to meet the therapist for the first time and you're told that the waiting lists are either closed or that you'll have to wait 18 months to make that happen, it's a huge stress to carry".
He said nobody should have to wait that length of time.
He said the State made a promise in 1999 to many institutional survivors that this wouldn't happen.
He said it was hugely important that the counselling programmes that One in Four provides for offenders was kept online during Covid.
He said this service highlights the fact that as a State, we don't provide enough services for those adults who come forward and admit that they've carried out a sexual offence against a child.
He said we need to make this much more accessible around the country and an everyday occurrence that someone can forward.
He said at the moment, the only time these offenders can get help and therapeutic services is if they are caught by the Gardai or put through the Courts system.
He said about 10% at the most will go through this system, while those who acknowledge what they've done, want to change and are willing to come forward for help don't have a place to go.
He said "we really need to step our services in that regard".