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  Introduction
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  Age and AD related mitochondrial changes in brain and peripheral tissues
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  Effect of APP accumulation on mitochondrial function
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  Mitochondria as a target and mediator of Aβ toxicity
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  Conclusions

Accumulating evidence suggest that alterations in energy metabolism are among the earliest events that occur in the Alzheimer disease (AD) affected brain. Energy consumption is drastically decreased in the AD‐affected regions of cerebral cortex and hippocampus pointing towards compromised mitochondrial function of neurons within specific brain regions. This is accompanied by an elevated production of reactive oxygen species contributing to increased rates of neuronal loss in the AD‐affected brain regions. In this review, we will discuss the role of mitochondrial function and dysfunction in AD. We will focus on the consequences of amyloid precursor protein and amyloid‐β peptide accumulation in mitochondria and their involvement in AD pathogenesis.