Telegraph story - Parrot is taking Prozac for depression following the death of its owner. Actually it's not Prozac (fluoxetine), probably the most well-known of the newer antidepressants - well, newer in the sense it first went on the UK market in 1989 - but Clomicalm (clomipramine), a traditional tricyclic antidepressant. Most prescribing of psychotropic medication in veterinary medicine is outside licensed indications. According to a recent veterinary psychopharmacology textbook the only label uses in the US for the treatment of behaviour problems are Clomicalm for separation anxiety in dogs and deprenyl for cognitive dysfunction in elderly dogs. So Clomicalm for parrots is unlicensed.
The company product information says Clomicalm was tested in clinical trials involving client-owned dogs. When used in conjunction with behavioural training, Clomicalm accelerated both the time to improvement and the final result of separation anxiety therapy compared to behavioural training alone. So behaviour training is a necessary component of therapy with Clomicalm. Perhaps it doesn't work on its own. The Telegraph story doesn't say whether it worked for the parrot.
(With thanks to Cornishcynders)