En español | Researchers have long known that many drugs can make us feel down or even depressed and that, as we age, our changing body chemistries put us at a greater risk for this side effect. But few doctors think to review the medications list when their patients have the telltale symptoms of depression: lack of energy, listlessness, feeling rundown, excessive fatigue, changes in appetite and sleeping patterns, sadness, despair. As a result, they often layer on top of the drugs causing those symptoms a new drug, such as an antidepressant, for treating them, which may in turn trigger additional side effects.

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Are you feeling depressed? One of the drugs you're on could be the cause. Read below for the major classes of drugs that can cause depression. If you suspect that your depression symptoms are linked to a prescription drug you're taking, talk to your doctor or health care provider right away. It's important that you do not discontinue them on your own.

1. Beta-blockers

Why they're prescribed: Beta-blockers are typically prescribed to treat high blood pressure (hypertension). Examples: atenolol (Tenormin), carvedilol (Coreg), metoprolol, propranolol (Inderal), sotalol (Betapace), timolol (Timoptic) and some other drugs whose chemical names end with "-olol." These drugs slow the heart rate and lower blood pressure by blocking the effect of the hormone adrenaline. Beta-blockers are also used to treat angina and for other conditions, such as migraines, tremors, irregular heartbeat and, in eye-drop form, certain kinds of glaucoma.

How they can cause depression: While scientists don't know exactly how beta-blockers cause depression, the three most commonly adverse effects reported with their use are fatigue, sexual dysfunction and depression.

Alternatives: For older people, benzothiazepine calcium channel blockers, another form of blood-pressure medication, are often safer and more effective than beta-blockers.

2. Corticosteroids

Why they're prescribed: Corticosteroids are used to treat inflammation of the blood vessels and muscles as well as rheumatoid arthritis, lupus, Sjögren's syndrome and gout. Examples: cortisone, methylprednisolone, prednisone and triamcinolone.

How they can cause depression: Research suggests that corticosteroids lower serotonin levels in the body, and it is known that lowered serotonin levels can cause depression and other psychiatric disorders. Withdrawal from corticosteroids can also trigger depression.

Alternatives: Acetaminophen (Tylenol), aspirin, tramadol (Ultram) or, if the situation requires it, a mild opiate like hydrocodone/acetaminophen (Vicodin). As we grow older, most joint pain from arthritis comes not from inflammation (for which corticosteroids may be used) but from immobility of the joint due to joint damage from years of inflammation.

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