Mental Health in Police stations

We recently became aware that most people arrested under 18 are asked to see a mental health person in the police station.  They on many occasions request that a consent form is signed to allow access to medical records. This is done without access to legal advice or even the presence of an appropriate adult.  Contained on this signed consent form is also has a tick box layout where access can be given to Police, social workers, Courts etc etc.  How to withdraw this consent is not explained. No written information is provided to the person detained. Where and who access the medical records is not known.  BREACH OF DPR!