40 year old lady is admitted to the casualty with abdominal pain and vomiting. She repos as able to hear people conspiring to harm her. The visual hallucinations staed along with the abdominal pain following the use of barbiturates. The most likely diagnosis is?

Porphyias are disorders of haem-synthesis leading to excessive accumulation of porphyrins. Acute Intermittent Porphyria (AIP) is an autosomal dominant condition affecting more females than males between the age of 20 and 50. Acute Intermittent Porphyria (AIP) classically presents with a triad of symptoms of colicky abdominal pain, motor neuropathy and psychosis. AIP is precipitated and aggravated by the use of barbiturates. Other psychiatric symptoms of AIP are anxiety, depression, insomnia, lability of mood and psychosis. Ref: Kaplan and Sadock's Synopsis of Psychiatry: By Benjamin J. Sadock, Harol I. Kaplan, Virginia A. Sadock, 2007, Page 371.