Other Psychotic Disorders MCQs

Ans. A. 5-HT Depression = Decrease in serotonin and norepinephrine. Serotonin is the most imPortant neurotransmitter in depression. Mania= Increased of norepipherine.

Clozapine competitively inhibits 5-HT3-receptors .( CORRECT OPTION A) Other antipsychotics mentioned in the question inhibit this receptor in a non-competitive fashion. Reference: Synopsis of Psychiatry, Eleventh edition, Chapter 29th, Page no. 1029.

ECG abnormalities occur in approximately 25% of all patients on antipsychotics. The most commonly reported changes are the prolonged QT interval(suggestive of repolarization disturbances), depressed ST segments and abnormal T waves. Thioridazine, pimozide, quetiapine, sertindole and droperidol prolong QTC interval to a higher extent than other antipsychotics . This predisposes to a fatal form of arrhythmia called torsade de pointes (polymorphic ventricular arrhythmia) leading to sudden death . Reference: Synopsis of Psychiatry, Eleventh edition, Chapter 29th, Page no. 1027.

Aripiprazole is thought to differ from most other antipsychotics in that it is a partial agonist at dopamine D2 receptors rather than an antagonist. It is also thought to have 5HT2A antagonist and 5HT1A partial agonist. Reference: Synopsis of Psychiatry, Eleventh edition, Chapter 29th, Page no. 1028.

Aripiprazole has no effect on the QTc interval. Chlorpromazine and Quetiapine are associated with a moderate effect on QTc .(Option B & D) Pimozide, Haloperidol and sertindole are drugs for which extensive QTc prolongation has been noted. (Option C) Reference: Synopsis of Psychiatry, Eleventh edition, Chapter 29th, Page no. 1028.

In comparison with other antipsychotics, aripiprazole has a very low relative incidence of sedation. All of the other antipsychotics like Chlorpromazine, Clozapine and Promazine are associated with high relative incidences of sedation .(Option B, C & D) Reference: Synopsis of Psychiatry, Eleventh edition, Chapter 29th, Page no. 1028.

A formal thought disorder is considered to be a schizophrenic language disorder It characterised by disordered speech, and results from disorganised thoughts. It is often a symptom of schizophrenia, mania, severe depression with psychosis and other psychotic disorders. Tangentiality is a formal thought disorder in which there is tangential association of ideas leading to disruption in the smooth continuity of speech. Thought insertion, thought broadcasting, thought withdrawal and thought block are Schneider’s first rank symptoms . (Option C & D) Delusion of persecution is a fixed belief in which patients believe that they are being followed, persecuted and spied on, and that the perceived persecutor will cause them harm. (Option A) Reference: PGNIP2, Cijo Alex, 2 nd Edition, Chapter 3, page no. 27

Explanation: For patients after their first psychotic episode, antipsychotic maintenance therapy is recommended for at least one year to reduce relapse risk, longer or indefinite treatment may be needed after more episodes.