There are many types of mood disorders:

• Major depressive disorder

The hallmark of major depressive disorder is prolonged bouts of extreme sadness.

• Bipolar disorder

Also called manic depression, people with bipolar disorder alternate between periods of depression and mania.Seasonal affective disorderSAD, or seasonal affective disorder, is a form of depression that’s associated with fewer hours of daylight in the far southern and northern latitudes, typically occurring between late fall and early spring.

• ADHD

ADHD, or attention deficit hyperactivity disorder, is an umbrella term for a range of behavioral disorders that occur more commonly in children but can be present in all ages. Symptoms include agitation, poor concentration, impulsivity, and hyperactivity.

• Anxiety

Anxiety is a lingering and overarching feeling of nervousness, worry, or unease, often about an imminent event or an air of uncertainty.

• Disruptive mood dysregulation disorder

This is a disorder of chronic, severe, and persistent irritability in children that can include recurring temper outbursts that aren’t consistent with the developmental age of the child.

Some people experience depression related to a medical illness that has impacted their life and ability. In some cases, depression can start after abuse of certain drugs or medications.