Improvement or worsening of psychotic symptoms after treatment with low doses of aripiprazole.

Aripiprazole, an antipsychotic recently introduced for clinical use, may worsen psychotic symptoms, even at low dose. In other cases, aripiprazole may exercise an antipsychotic action and induce extrapyramidal side-effects, even at low dose. There are no clear-cut criteria to differentiate the patients whose psychotic symptoms will or will not respond to aripiprazole favourably. Conversely, the effectiveness on negative symptoms seem consistent both in patients with or without antipsychotic response. A low dose may be indicated at the beginning of treatment to assess the kind of response.