The American Psychiatric Association describes depression as a common and serious medical disorder that impacts how someone feels, thinks and behaves. Most people recognize depression as a mental illness that includes feelings of sadness, thoughts of suicide and a general inability to enjoy life. However, there are a wide variety of symptoms that have nothing to do with feeling down and out or actively wanting to die. In this article, learn about the different types of depression and lesser known symptoms to help you recognize a potential problem.

Type of Depression

To some people, depression may be easily explained by traumatic circumstances or weak-mindedness that causes people to be easily overwhelmed, but the disorder is so much more than that and can strike when you least expect it.

The different types of depression include:

• Major depression, which typically includes severe symptoms that impact daily life, with episodes that occur one or more times during a person's lifetime.
• Persistent depressive disorder, (also known as dysthymia) which lasts longer than two years and has periods of severe and less-severe symptoms.
• Psychotic depression, which includes some type of psychosis in addition to depression.
• Postpartum depression, which is more commonly known as "baby blues" and occurs after the birth of a child.
• Seasonal affective disorder (SAD), which occurs during winter months when there is less natural sunlight.
• Bipolar disorder, which is not a depressive disorder, but includes periods of depression as well as periods of "mania", or extreme high moods.

Each of these types of depression can affect women or men, including postpartum depression (called Paternal Postnatal Depression, or PPND). Major depressive disorder impacts the most people, affecting 14.8 million adults in the U.S., and is more common in women than men. Persistent depressive disorder affects approximately 3.3 American adults per year, with a median onset age of 31.1 years old.

Lesser Known Symptoms of Depression

With three to five percent of adults experiencing depression at some point in their lives, it's likely that you are at least familiar with the disease. Symptoms including persistent sadness, feelings of hopelessness, worthlessness or guilt, a loss of interest in hobbies and activities, and thoughts of suicide are fairly well-known, but other symptoms of depression can seem totally unrelated.

Lesser known, but not uncommon symptoms of depression include:

• Rapid weight changes: This can mean a sudden gain or loss of weight, caused by a loss of appetite or forgetting to eat, or by "comfort" binging.
• Anger and irritability: Anger and irritability seem pretty far off from sadness, but if you notice someone is less patient and more prone to flying of the handle, this can be a sign of depression.
• Boredom: Things that used to sound fun may suddenly stop motivating someone to participate. Rather than feeling too sad to want to get out of bed, a person suffering from depression may just feel bored and uninspired.
• Aches and pains: Physical discomfort, when not related to other illness, can be signs of depression. This discomfort can range from skin sensitivity to headaches to muscle and joint pain.
• Anxiety: Depression and anxiety go hand in hand. Worrying and stressful thinking often lead to hopelessness and thoughts of giving up.
• Passive thoughts of dying: Passive thoughts of dying are different from thoughts of suicide in that people think about being dead rather than considering or planning how to kill themselves. For example, they may think that it would be better if they could go to sleep and never wake up.
• Confusion and trouble concentrating: Forgetfulness, problems focusing and disorganization can all be symptoms of depression, particularly when they appear suddenly.
• Changes in sleep patterns: It may seem like people who are depressed sleep a lot more than normal, but the converse can also be true. Depression can also cause people to wake up at odd hours or experience very restless sleep.
• Feeling numb: Depression may seem like a disease characterized by a lot of painful emotions, but numbness is another possible symptom. The inability to feel pain, sadness, loss, or heartache may seem like a good thing, but numbness associated with depression also means failing to feel joy and love.

Depression is a serious disease, just like hypertension or diabetes. Symptoms can vary wildly, but the symptoms listed in this article can give you an idea about the diversity of depression red flags.

If you or someone you know experiences sudden changes in behavior, though patterns or emotions, it is important to seek professional medical help. Your family doctor can refer you to a psychiatrist or psychologist for further assistance and counseling. Depression in all its forms is treatable and no one should suffer needlessly.