Paruresis and substance abuse testing (drug and alcohol)
People who experience shy bladder syndrome are under extra pressures if required to provide a urine sample: whether by the police, in prison, or in the workplace.
Shy bladder is not a condition that you either have or do not have. Anecdotal evidence exists that individuals who have never experienced urinary retention have "locked-up" when faced with the proximity and observational conditions used in drug testing. Evidence provided by an officer in the USA military responsible for Mandatory Drug Testing (MDT), where all personnel had to be tested, was that: 30% of men had no problem at all with observed testing; 50% struggled to varying degrees but managed; 20% were unable to provide a sample and were told to sit on a bench and to drink. No figures were available for what percentage were totally unable to give a sample in those conditions. However it does show that even the "normal" population struggles, and that a minority "fails".
Ignorance of the body's neural mechanism for urination i.e. that a threat causes the autonomic nervous system to disable the urinary process, means testers assume that time and/or fluid loading will inevitably result in a sample being produced. Unfortunately this is not the case: however much the individual wishes to void, the nervous system has literally "closed the tap", and has relaxed the bladder muscles removing the voiding pressure.