Is it permissible to pray the Friday prayer two rak'ahs at home behind the imam of the mosque, for someone who suffers from severe social phobia that prevents him from going to the mosque, knowing that he hears the sermon and the prayer clearly?

The questioner is advised to consult doctors and take medication, as seeking treatment is permissible. There is no blame upon him for missing Friday prayer if he is ill, but if he is able to catch one rak'ah, it becomes obligatory upon him to do so; otherwise, there is no sin upon him. If it is permissible to miss Friday prayer, then he must pray Dhuhr at home and not pray with the imam's prayer. The more cautious approach is to make up what was prayed in this manner.