Is there some kind of reason why an antidepressant cannot be prescribed? They are typically the first line treatment for anxiety disorders and depression.

A doctor may go for an antipsychotic if there is a mood component such as high risk of a manic episode. Certain antipsychotics have antidepressant and anxiolytic properties, the notable one being Seroquel and Risperdal or Zyprexa not being too far off.