Important note: The government altered this rule in March 2017, so that it was no longer possible to use this particular descriptor
if the difficulties were caused by psychological distress.
However, this change was found to be unlawful by the High Court, and the government has accepted this and changed
this rule back to what it was before they altered it.
The upshot of all this is that if you cannot plan the route of a journey, it doesn't matter whether this is because
of sensory or cognitive deficits, or because of mental health problems.
Last updated May 2018