The Bereitschaftspotential in Schizophrenia and Depression

Abstract

The earliest investigation of the Bereitschaftspotential (BP) in schizophrenia was published three decades ago by M. Timsit (Timsit, 1970, Timsit-Berthier et al., 1973a). At about the same time, abnormal movement-related cortical potentials in psychiatric patients had also been identified by Dongier (1973). Ten years later, Kornhuber (1983) described findings of lower amplitudes and longer latencies in the BP of patients with schizophrenia. These findings were later followed by studies conducted by Chiarenza et al. (1985) and Papakostopoulos et al. (1985a). To date, a number of journal papers have been published reporting studies investigating the BP in schizophrenia. Other related cortical potentials such as the contingent negative variation (CNV) and the post-imperative negative variation (PINV) have also been recorded in schizophrenia (eg Tismit-Berthier et al, 1973b; Klein et al, 1996; Rockstroh et al, 1994; Wagner et al, 1996; Verleger et al, 1999; ). A handful of studies have also examined the BP or CNV in depression (eg Their et al, 1986; Khanna et al, 1989; Knott et al, 1991; Haag et al, 1994; Heimberg et al, 1999). The BP, the CNV and the lateralized readiness potential have also been recorded in other psychiatric disorders such as anxiety states (eg Boudarene & Tismit-Berthier, 1997) and alcoholism (Marinkovic et al, 2000) in a few studies. In this chapter, I will focus on the studies of the BP in schizophrenia and depression, but do not attempt to produce an exhaustive or all-inclusive review. I will first describe the studies which have investigated the BP in patients with schizophrenia and depression, followed by a summary and critical evaluation of their results before finally considering their implication for the pathophysiology of these disorders. However, before reviewing the experimental evidence, let us consider the rationale behind studying the BP in Psychiatric disorders such as schizophrenia and depression.