Seasonal affective disorder is real—and often debilitating.
Some 15 million Americans a year struggle with depression, an illness that comes in many forms—from major depression and seasonal affective disorder, to dysthymia and bipolar disorder. Depression is an illness that increasingly afflicts people worldwide, interfering with concentration, motivation and many other aspects of everyday functioning.
Ah, happiness, that elusive state. Philosophers, theologians, psychologists, even economists, have long sought to define it, and since the 1990s, a whole branch of psychology—positive psychology—has been dedicated to pinning it down and propagating it.
Optimists have a tendency to make lemonade out of lemons, and to then see the glass as half-full rather than half-empty. It's an admirable quality, one that can positively affect mental and physical health.
The glass is half-empty and storm-clouds loom overhead (never with a silver lining). Pessimists get a lot of flak for negativity, and their health may take a beating, too. But they make better leaders and are more resistant to false advertising.
Questions of personality have vexed mankind from the dawn of personhood: can people change? How do others perceive me? What is the difference between normal and pathological behavior? One's personality is so pervasive and all-important that it presents a clinical paradox of sorts: it is hard to assess our own personality, and impossible to overlook that of others.
Motivation is literally the desire to do things. It's the difference between waking up before dawn to pound the pavement and lazing around the house all day. It's the crucial element in setting and attaining goals—and research shows you can influence your own levels of motivation and self-control.