context: Depression usually strikes more than once in a lifetime. For many people, it can become a chronic or lifelong illness, with several relapses or recurrences. On average, most people with depression will have four to five episodes during their lifetimes. Doctors define relapse as another episode of depression that happens fewer than six months after you've been treated for acute depression. A recurrence is a new episode that comes after six months or longer since the previous episode has resolved. Regardless of the timeline, it can be demoralizing to feel depression symptoms, such as sadness, fatigue, and irritability, creeping back into your life. If you believe that you're facing depression a second time (or more), talk to your primary care doctor, psychiatrist, or therapist right away about getting treatment again. A depression relapse or recurrence can be treated in various ways, sometimes through a combination of therapies. For example, your doctor may recommend both antidepressant treatment and psychotherapy. Antidepressants Doctors use several different types of drugs to treat depression, including: Selective serotonin reuptake inhibitors ( SSRIs) Serotonin and norepinephrine reuptake inhibitors ( SNRIs) Norepinephrine and dopamine reuptake inhibitors ( NDRIs), which include bupropion Older classes of antidepressants can be effective, too, but aren't used as frequently today because they pose the potential risk of serious side effects. These older drugs include: Tricyclics Monoamine oxidase inhibitors ( MAOIs) In addition, your doctor may pair your antidepressant with atypical antipsychotic medicines, mood stabilizers, anti-anxiety drugs, stimulants, or other medications. Ask your doctor if you need to take antidepressants or other medications for your new episode of depression. If you're already on "maintenance therapy" -- for example, using an antidepressant to prevent recurrence -- your doctor may alter the dose of an existing medicine or otherwise change your current drug regimen to find more effective treatment. Psychotherapy Counseling, or "talk therapy," can help you to understand your problems, including new issues that have arisen since you were last treated for depression. You'll explore better ways to cope or to solve problems. Through psychotherapy, you can also learn how to manage your own thoughts and actions so that you feel less depressed. Many types of psychotherapy are effective. Here are two that are commonly used: Cognitive-behavioral therapy ( CBT): This form of counseling helps you to identify and change negative beliefs and behaviors that contribute to your depression. By replacing these patterns with healthier, more realistic thoughts and actions, you can avoid the traps that worsen your depression. Interpersonal therapy ( IPT): This type of therapy aids you in understanding and working through difficult relationships or interactions with people that may be contributing to your depression. If you're open to joining a depression support group, ask your counselor or doctor for a recommendation. Electroconvulsive therapy If your depression is severe or life threatening or does not respond to treatment with multiple antidepressants and other medicines, another option is electroconvulsive therapy. The treatment involves giving general anesthesia to the patient, along with a muscle relaxant to prevent body movement. ECT passes an electrical current through the brain to induce a seizure. Although doctors aren't sure why, it is thought that the treatment changes the functioning and efficiency of brain areas that regulate emotion. Other types of brain stimulation therapies can also treat severe depression, including vagus nerve stimulation ( VNS) and repetitive transcranial magnetic stimulation (r TMS). After patients have been treated for an acute bout of depression, doctors sometimes place them on maintenance therapy to try to prevent another episode, especially if they're at high risk for a recurrence. Talk to your doctor about whether you need maintenance therapy. For this type of ongoing treatment, which can last one year or longer, you may continue taking an antidepressant, with or without psychotherapy. Ask how long you may need maintenance therapy. In some cases, patients choose watchful waiting instead of maintenance therapy with antidepressants. In this case, they'll keep an eye out for depression symptoms and restart an antidepressant at the first sign of a recurrence. While you can't just "shake off" your depression, you can certainly take steps to improve your mood and outlook. Be sure to get the right amount of sleep and steer clear of alcohol and illegal drugs, which can worsen depression. In addition to seeing your doctor immediately, consider these tips from the National Institute of Mental Health: Try to be active and exercise. Go to a movie, sporting event, or other activity that you once enjoyed. Set realistic goals for yourself. Break up large tasks into small ones, set some priorities, and do only what you can manage without causing stress for yourself. Try to spend time with other people. Confide in a trusted friend or relative. Don't isolate yourself, and let others help you. Expect your mood to improve gradually, not immediately. Do not expect to suddenly "snap out of" your depression. Often, during treatment, your sleep and appetite will begin to improve before your depressed mood improves. When possible, postpone important decisions, such as getting married or divorced or changing jobs, until you feel better. Discuss decisions with others who know you well and have a more objective view of your situation. Negative thoughts are a hallmark of depression, but take heart that positive thinking will replace them as your depression responds to treatment. Continue to educate yourself about depression, including any ways that might help you to prevent recurrences.