Coronavirus: Long waiting list for reopened addiction centre
Tommy Canning, who is head of treatment at Northlands Addiction Centre, said people who need help are unable to access treatment.
Because of social distancing the centre is operating at 50% capacity.
Mr Canning said a new centre was needed in the city to properly function moving forward from coronavirus.
The centre reopened this week after closing its doors for residential treatment during lockdown.
In May, Northlands recorded a 50% drop in the number of people contacting the organisation.
'Mixed emotions'
Speaking to BBC Radio Foyle, Mr Canning said although he is "delighted to reopen" the services the centre can offer have been seriously affected by coronavirus.
Staff have had to readjust to longer working hours and many addiction programmes have had to be condensed from six weeks into four weeks