Many people experience changes in mood with the change of season. Seasonal affective disorder (SAD) is an extreme form of these common seasonal mood cycles. How seasonal changes cause depression is unknown, but most of the research into mechanisms and treatment has focused on changes in levels of the brain chemicals melatonin and serotonin in response to changing lengths of exposure to light and darkness.
Hay fever is an allergic condition triggered by the immune system’s response to inhalant substances (frequently pollens). Researchers have yet to clearly understand why some people’s immune systems over-react to exposure to pollens while other people do not suffer from this problem. Symptoms of hay fever are partly a result of inflammation that, in turn, is activated by the immune system.
Many people experience changes in mood with the change of season. Seasonal affective disorder (SAD) is an extreme form of these common seasonal mood cycles. How seasonal changes cause depression is unknown, but most of the research into mechanisms and treatment has focused on changes in levels of the brain chemicals melatonin and serotonin in response to changing lengths of exposure to light and darkness.
Seborrheic dermatitis is a common inflammatory condition of the skin. Cradle cap is a type of seborrheic dermatitis found in infants; it is usually self-limiting and subsides by the age of six months. A qualified physician should diagnose these conditions. Much of the research on this condition has been performed on infants and its applicability to the adult population is unclear.
