The subject invention concerns materials and methods for treating and/or preventing diseases associated with accumulation of Aβ peptide in neural tissue. The subject invention also concerns materials and methods for treating and/or preventing stress disorders, such as post-traumatic stress disorder (PTSD). In one embodiment, a method of the invention comprises administering a therapeutically effective amount of cotinine, or a pharmaceutically acceptable salt thereof, to a person or animal in need of treatment. The methods of the invention can be used to prevent and/or treat Alzheimers disease and Parkinsons disease. The subject invention also concerns compositions that comprise cotinine, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier, diluent or adjuvant. The subject invention concerns materials and methods for detecting and diagnosing conditions associated with accumulation of Aβ peptide in neural tissue, such as Alzheimers disease and Parkinsons disease, using the chemical cotinine.
