The motor symptoms of Parkinson's disease (PD) are caused primarily by degeneration of dopaminergic neurons in the substantia nigra. The nonmotor symptoms of the disease are thought to be caused by degeneration of other neurotransmitter systems. No disease-modifying drugs are available for treatment of PD.

View the Comparison Table: Drugs for Parkinson's Disease

View the Comparison Table: Drugs for Alzheimer's Disease

The FDA has approved an extended-release fixed-dose combination of dextromethorphan and bupropion (Auvelity – Axsome) for treatment of major depressive disorder (MDD) in adults.

Influenza is generally a self-limited illness, but pneumonia, respiratory failure, and death can occur, especially in persons at increased risk for influenza complications (see Table 1). Updated information on influenza activity and antiviral resistance is available from the CDC at cdc.gov/flu.

Alzheimer's disease (AD) is the most common cause of dementia, but cognitive decline is also associated with other neurological conditions such as Parkinson's disease, dementia with Lewy bodies, vascular dementia, and frontotemporal dementia.

Overweight is generally defined as a body mass index (BMI) between 25 and 29.9 kg/m2 in adults. A BMI ≥30 is considered obese (criteria differ slightly in Asian patients). In patients with an elevated BMI, a 5-10% reduction in weight has been associated with a reduction in the risk of developing type 2 diabetes, hypertension, and dyslipidemia. Diet, exercise, and behavior modification are the traditional methods for losing weight, but they are often inadequate; the American College of Cardiology no longer recommends that all patients try lifestyle modification alone before adding...