Project 7

Typical and Atypical Antipsychotic Drug Treatment and PPI in Patients with Schizophrenia

That patients suffering from schizophrenia and treated with typical neuroleptics exhibit decreased PPI has been well-established since the 1970’s (Braff et al. 1978). What is controversial is whether or not a similar decrease in PPI occurs in patients treated with atypical antipsychotics (Kumari et al. 2002, 2003; Mackeprang et al. 2002; Oranje et al. 2002).One issue with standard methods of PPI testing is that the attention of participants to the acoustic stimuli is unconstrained and not typically measured. Attention to or away from startling stimuli can alter the magnitude of the startle response (Acocella and Blumentha 1990;), and can alter PPI under some conditions (Kedzior and Martin-Iverson 2005). Experiments addressing this issue in patients are planned for 2007

References

Acocella C, Blumentha T (1990) Directed attention influences the modification of startle reflex probability. Psychological Reports 66: 275-85

Braff DL, Stone C, Callaway E, Geyer M, Glick I, Bali L (1978) Prestimulus effects on human startle reflex in normals and schizophrenics. Psychophysiology 15: 339-343

Hince DA, Martin-Iverson MT (2005) Differences in prepulse inhibition (PPI) between Wistar and Sprague-Dawley rats clarified by a new method of PPI standardization. Behavioral Neuroscience 119: 66-77

Kedzior KK, Martin-Iverson M (2005) Chronic cannabis use is associated with attention-modulated reduction in prepulse inhibition of the startle reflex in healthy humans. Journal of Psychopharmacology 20: 471-484

Kumari V (2002) Effects of typical and atypical antipsychotics on prepulse inhibition in schizophrenia: a critical evaluation of current evidence and directions for future research. Psychopharmacology 162: 97-101

Kumari V, Zachariah E, Galea A, Jones HC, Das M, Mehrotra R, Taylor D, Sharma T (2003) Effects of acute procyclidine administration on prepulse inhibition of the startle response in schizophrenia: a double-blind, placebo-controlled study. Journal of Psychopharmacology 17: 89-95

Mackeprang T, Kristiansen K, Glenthoj B (2002) Effects of antipsychotics on prepulse inhibition of the startle response in drug-naive schizophrenic patients. Biological Psychiatry 52: 863-873

Martin-Iverson MT, Stevenson K (2005) Apomorphine effects on emotional modulation of the startle reflex in rats. Psychopharmacology 181: 60-70

Oranje B, van Oel C, Gispen-de Wied C, Verbaten M, Kahn R (2002) Effects of typical and atypical antipsychotics on the prepulse inhibition of the startle reflex in patients with schizophrenia. Journal of Clinical Psychopharmacology 22: 359-365