Depression isn’t a one-size-fits-all illness, according to the Harvard University Medical College Healthbeat newsletter.

 Just like a rash or heart disease, depression can take many forms. As you’ll see, there’s a cluster of symptoms that are typically present, but one person’s experience of depression often differs from another’s. Definitions of depression — and the therapies designed to ease this disease’s grip — also continue to evolve.

What is major depression?

Major depression may make you feel as though work, school, relationships, and other aspects of your life have been derailed or put on hold indefinitely. You feel constantly sad or burdened, or you lose interest in all activities, even those you previously enjoyed. This holds true nearly all day, on most days, and lasts at least two weeks. During this time, you also experience at least four of the following signs of depression:
• a change in appetite that sometimes leads to weight loss or gain
• insomnia or (less often) oversleeping
• a slowdown in talking and performing tasks or, conversely, restlessness and an inability to sit still
• loss of energy or feeling tired much of the time
• problems concentrating or making decisions
• feelings of worthlessness or excessive, inappropriate guilt
• thoughts of death or suicide, or suicide plans or attempts.

Other signs can include a loss of sexual desire, pessimistic or hopeless feelings, anxiety, and physical symptoms such as headaches, unexplained aches and pains, or digestive problems.

What is dysthymia?

Mental health professionals use the term dysthymia (dis-THIGH-me-ah) to refer to a low-level drone of depression that lasts for at least two years in adults or one year in children and teens. While not as crippling as major depression, its persistent hold can keep you from feeling good and can intrude upon your work, school, and social life. Unlike major depression, in which relatively short episodes may be separated by considerable spans of time, dysthymia lasts for an average of at least five years.

If you suffer from dysthymia, more often than not you feel depressed during most of the day. You may carry out daily responsibilities, but much of the zest is gone from your life. Your depressed mood doesn’t lift for more than two months at a time, and you also have at least two of the following symptoms:
• overeating or loss of appetite
• insomnia or sleeping too much
• tiredness or lack of energy
• low self-esteem
• trouble concentrating or making decisions
• hopelessness.

Sometimes an episode of major depression occurs on top of dysthymia; this is known as double depression.

What is bipolar disorder?

Bipolar disorder always includes one or more episodes of mania, characterized by high mood, grandiose thoughts, and erratic behavior. It also often includes episodes of depression. During a typical manic episode, you would feel terrifically elated, expansive, or irritated over the course of a week or longer. You would also experience at least three of the following symptoms:
• grandiose ideas or pumped-up self-esteem
• far less need for sleep than normal
• an urgent desire to talk
• racing thoughts and distractibility
• increased activity that may be directed to accomplishing a goal or expressed as agitation
• a pleasure-seeking urge that might get funneled into sexual sprees, overspending, or a variety of schemes, often with disastrous consequences.

How to cope when a loved one is depressed, suicidal, or manic

Like a pebble thrown into a pond, depression, dysthymia, and bipolar disorder create ripples that spread far from their immediate point of impact. Those closest to people who have these illnesses often suffer alongside them. It’s upsetting and often frustrating to deal with the inevitable fallout. But you can do a lot to help a loved one and yourself handle this difficult period.

Encourage him or her to get treatment and stick with it. Remind the person about taking medication or keeping therapy appointments. Don’t ignore comments about suicide. If you believe your loved one is suicidal, call his or her doctor or therapist. If neither is available, call a local crisis center or emergency room.

Care for yourself. Being a caretaker is a difficult job. You may want to seek individual therapy or join a support group. Numerous mental health organizations sponsor such groups and can also provide you with information on the illness and the latest treatments.

Offer emotional support. Your patience and love can make a huge difference. Ask questions and listen carefully to the answers. Try not to brush off or judge the other person’s feelings, but do offer hope. Suggest activities that you can do together, and keep in mind that it takes time to get better. Remind yourself that a disease is causing your loved one to act differently or perhaps be difficult. Do not blame him or her, just like you wouldn’t if it were chronic physical pain that caused the person to change in certain ways.

Try to prevent reckless acts during manic episodes. It’s all too common for a person to make poor decisions when manic, so it’s a good idea to try to prevent this problem by limiting access to cars, credit cards, and bank accounts. Watch for signs that a manic episode is emerging. Disruption of sleep patterns can trigger an episode, so support your loved one in keeping a regular sleep schedule. Consistent patterns for other activities such as eating, exercising, and socializing may also help.