The development of the antipsychotic drugs in the 1950s
was a major breakthrough in the treatment of schizophrenia,
and these drugs have now become the mainstay of
treatment for the disorder. The traditional or firstgeneration
antipsychotics (FGAs) are clearly effective in the
treatment of the positive symptoms of psychosis such as
hallucinations and delusions. These drugs do not, however,
alleviate the negative symptoms of schizophrenia, and are
known to produce extrapyramidal side effects such as
© 2006 The Authors. Journal compilation © 2006 Blackwell Publishing Ltd 731
The metabolic syndrome and schizophrenia
drug-induced Parkinsonism, dystonic reactions and akathisia
at clinically effective doses. These side effects can result
in distress, stigma, diminished function and failure to take
the medications as prescribed (Usher 1997; Therapeutic
Guidelines Ltd 2003; Consensus Development Conference
on Antipsychotic Drugs and Obesity and Diabetes 2004).
The second-generation antipsychotics (SGAs), on the other
hand, have fewer or no extrapyramidal side effects, are
more effective at treating the cognitive impairment and
negative and affective symptoms of the illness, and are
usually better tolerated (Therapeutic Guidelines Ltd
2003; Consensus Development Conference on Antipsychotic
Drugs and Obesity and Diabetes 2004; Masand &
Mago 2005). For these and other reasons, the SGAs are
increasingly used over the FGAs in the treatment of psychotic
disorders, including schizophrenia (Lambert & Castle
2003). Nonetheless, the various SGAs have their own
side-effect profiles, and some have been linked to the development
of metabolic syndrome in people taking them for
the treatment of schizophrenia (Henderson et al. 2005).
Numerous case reports also indicate a worsening of glycaemic
control or new-onset diabetes, including diabetic
ketoacidosis