There are many avenues of continuing research for Alzheimer's disease, only some of which are progressing through medical clinical trials. Some areas of research include:

• Genetics. Scientists believe that they may have discovered genes linked to the development of Alzheimer's disease. The genes, ApoE4 and SORL1, appear to be more common in people with Alzheimer's disease. However, not all people with the gene develop Alzheimer's disease and some people without the gene may also develop the disease. Therefore, it is thought that these genes may make carriers more susceptible to Alzheimer's disease, although other factors may also be involved in its development.
  
  
• Inflammation. Some studies have indicated that inflammation around the brain may contribute to the progression of Alzheimer's disease. This has lead to the belief that medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) may be beneficial as both a preventive measure and as a means of slowing disease progression. However, clinical trials have shown negative results. Moreover, some types of NSAIDs such as aspirin or ibuprofen may interact poorly with Alzheimer’s medications. Chemicals called cytokines are produced during inflammation and may be detectable in blood tests to make it possible to diagnose Alzheimer's disease earlier.
  
  
• Antibiotics. A few studies have found the presence of bacteria including Chlamydophila in the brains of Alzheimer's patients, and lab studies have shown that some antibiotics can interfere with the accumulation of dangerous proteins in the brain. However, more study is needed before antibiotics become part of standard Alzheimer's care.
  
  
• Vaccine. Although there is no cure for Alzheimer's disease, scientists have been working on various types of vaccines that may be able to prevent the development of the plaques and tangles that seem to be closely connected with Alzheimer's disease. One attempt was the AN-1792 vaccine, which was designed to enable the immune system to recognize and attack amyloid plaques. However, despite promising results, clinical trials of the vaccine were stopped when it was discovered that the vaccine may have contributed to inflammation of the brain and spinal cord experienced by some of the participants.
  
  
• Estrogen. Some studies have indicated that estrogen may be linked to the development of Alzheimer's disease, although the precise relationship is unknown. It appears that estrogen used by menopausal women may protect the brain and slow the progression of Alzheimer's disease. However, in clinical trials, this link was not confirmed and evidence showed that the use of estrogen with progestin (a common combination in the contraceptive pill) may increase the risk of developing Alzheimer's disease. In addition, use of hormone replacement therapy has been linked to increased risks of breast cancer in women.
  
  
• Testosterone. Older men with lower testosterone levels appear to be a greater risk of developing Alzheimer's disease or cognitive impairment. Only a few studies have been conducted so far on the value of testosterone supplementation among older men to enhance cognitive function. Results have been mixed.
  
  
• Insulin. One early study showed that insulin therapy reduced the level of beta amyloid protein in the blood (the protein that causes the plaques associated with Alzheimer's disease). It appears that insulin is somehow related to the protein's metabolism, and that people with higher levels of insulin have fewer symptoms of dementia.
  
  
• Diagnosis. Scientists are working on a number of ways to confidently detect and thus treat Alzheimer's disease earlier than what is currently possible. Methods under investigation include blood tests, modified imaging tests, genetic tests and improved risk factor calculations.