Almost two-thirds of people undergoing psychological therapy in Dorset are waiting longer than a month between treatment appointments, according to NHS figures.

In May, around 510 of the 800 people who had a second treatment session in the Dorset clinical commissioning group (CCG) waited for more than a month between appointments - a rate of 64 per cent.

Around 175 waited more than three months between their first and second appointment which accounted to 22 per cent of the total.

Mental health campaigners say that this is too long to wait - and best practice guidelines advise that psychological therapies should be delivered on a weekly or fortnightly basis.

As part of it's Improved Access to Psychological Therapy (IAPT) programme, NHS targets state that 75 per cent of service users should have their first treatment appointment within six weeks of referral, and 95 per cent within 18 weeks - there is no target for second appointments.

The IAPT programme aims to improve the delivery of therapy services across a range of conditions, including depression, anxiety, obsessive-compulsive disorder and post-traumatic stress with guidelines stating that it is not good practice to delay a course of treatment for an extended period of time after the initial appointment.

In the Dorset CCG area, 93.9 per cent of the 1,155 people having their first appointment in May waited for less than six, and 99.6 per cent waited less than 18 weeks.

By these measures, Dorset CCG has far exceeded these targets.

Mind's Senior Policy and Campaigns Officer Emily Waller said: "Because of the targets, all the emphasis is on the wait for the first appointment, and not on the subsequent appointments.

"These figures highlight the fact that some talking therapies aren't being delivered in the best way possible.

"Although targets for accessing the first appointment are being met, this data shows that there are still long waits between sessions in parts of the country.

"This makes it more likely for people using the service to become more unwell, or disengage with the service altogether."

Nationally, 90 per cent of people waited less than 6 weeks to start treatment, and 99 per cent of people waited less than 18 weeks.

The British Association for Counselling and Psychotherapy (BACP) expressed concerns that the IAPT workforce has not been sufficiently expanded to deal with the demand for the service.

A BACP spokesperson said: "It is vital that talking therapies are available as and when they are required.

"The right support at the right time can improve long-term effects on self-esteem."

In response, Dorset HealthCare University NHS Foundation Trust admitted that their Psychological Therapy Service was "the victim of its own success" saying that it was "significantly over-referred" with more than 22,000 referrals expected this year alone.

A spokesman added: "However, the service is currently exceeding its assessment targets, and our waiting times are shorter than many other areas of the country.

"To help us do even better, the Dorset Clinical Commissioning Group has now provided additional funding to expand the service.

"This will enable us to reduce waiting times further, and provide specialist therapists to work with people with long-term health conditions such as diabetes and chronic pain.

“There are also plans to utilise digital technology – such as Skype, therapy delivered by text message and the use of mobile phone apps – to provide even more treatment options for our patients.”