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.
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.
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.
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.
3. Benzodiazepine hypnotics
Why they're prescribed: These drugs, also known as benzodiazepine tranquilizers, are typically prescribed to treat anxiety and insomnia and to relax muscles. Examples: alprazolam (Xanax), diazepam (Valium), estazolam (ProSom), flurazepam (Dalmane), lorazepam (Ativan), temazepam (Restoril) and triazolam (Halcion).
How they can cause depression: Benzodiazepines are central nervous system depressants. If not fully metabolized in the liver, they can build up in the body to toxic levels. The resulting "hangover effect" can manifest itself as depression. Older people are more likely to experience these residual effects because their livers often lack a key enzyme needed to metabolize the drugs.
Alternatives: Give yourself every chance to sleep well naturally: Go to bed and wake up at the same times every day, avoid meals within two hours of bedtime, allow 30 minutes before bedtime for a relaxing pre-sleep ritual, and so forth. Melatonin, a dietary supplement that helps control sleep and wake cycles, may also be worth trying.
4. Parkinson's drugs
Why they're prescribed: One approach to treating the symptoms of Parkinson's disease is to use drugs to adjust the levels of dopamine (a neurotransmitter) in the brain, as the motor symptoms associated with the disease result from the death of dopamine-generating cells in a region of the midbrain.
For example, levodopa, the most commonly prescribed Parkinson's medication, is converted into dopamine on entering the brain; it's typically combined with carbidopa, which helps prevent it from breaking down before it can reach the brain and take effect, in brand-name products such as Atamet, Sinemet and Stalevo.
Another approach is the use of dopamine agonists such as pramipexole (Mirapex) and ropinorole (Requip), which work by stimulating the dopamine receptors in the brain, thus mimicking the activity of dopamine.
How they can cause depression: Dopamine is one of three basic neurotransmitters that have been associated with depression (the others are serotonin and norepinephrine). Researchers believe that prolonged exposure to higher levels of dopamine may cause depression.
Alternatives: As many as 25 percent of all patients who are diagnosed with Parkinson's don't actually have the disease, so it's important to make sure that you're not among those misdiagnosed. Older people with essential tremors — involuntary trembling or quivering of the hands, limbs or other parts of the body — are often misdiagnosed as having Parkinson's. There's also drug-induced Parkinson's, which can often be reversed if the offending medication is discontinued early enough. (Older patients, for example, frequently develop parkinsonism after being prescribed antipsychotic drugs such as Haldol, Mellaril, Stelazine and Thorazine.) A systemic neurological examination is the best way to test for Parkinson's disease. And if you need to take levodopa, the dose can be reduced with the use of a COMT-inhibitor, a relatively new type of drug that blocks an enzyme in the body from metabolizing the levodopa before it reaches the brain.
5. Hormone-altering drugs
Why they're prescribed: Hormone-altering drugs are used to treat a variety of conditions. Estrogen (Premarin), for example, is typically prescribed for hot flashes and other postmenopausal symptoms .
How they can cause depression: Manipulating hormone levels in the body can cause a variety of problems, particularly as medications interact with the central nervous system. Studies show that changes in hormonal levels are significantly associated with the appearance of symptoms of depression.
Alternatives: Once again, it's important to try to identify the cause of the symptoms. Review the medications you're taking — prescription and over the counter — with your doctor to identify some problems that can be corrected without additional drugs.
Why they're prescribed: Stimulant medications, such as methylphenidate (Ritalin) and modafinil (Provigil), are often prescribed to treat excessive daytime sleepiness, whether caused by hypersomnia, narcolepsy or sleep apnea. They're also prescribed for ADHD and fatigue.
How they can cause depression: Stimulant medications increase the level of dopamine in the body. Researchers believe that prolonged exposure to higher levels of dopamine may cause depression.
Alternatives: As with insomnia (see benzodiazepine hypnotics, above), it's important to identify the cause of excessive daytime sleepiness. Other medications you're taking — whether prescription or over the counter — could be responsible. Drugs with sedating effects, for example, are among the most common causes of excessive daytime sleepiness. (These include alpha- and beta-blockers, anti-diarrheal agents, antihistamines, antipsychotics, antispasmodics, cough suppressants, epilepsy drugs, skeletal muscle relaxants, Parkinson's drugs and some antidepressant medications.)
Nondrug causes of excessive daytime sleepiness include sleep deprivation, obstructive sleep apnea (when the throat muscles intermittently relax and block the airway during sleep) and depression. When such underlying conditions are treated appropriately, there's rarely, if ever, any need for the use of stimulants.
Why they're prescribed: Anticonvulsant drugs, which have long been used to treat seizures, are increasingly being used to treat other medical conditions, including neuropathic pain, bipolar disorder, mood disorders and mania. Examples: carbamazepine (Tegretol), gabapentin (Neurontin), lamotrigine (Lamictal), pregabalin (Lyrica) and topiramate (Topamax).
How they can cause depression: Anticonvulsants are believed to work by affecting neurotransmitters, which act as chemical messengers in the brain. They may, for example, limit seizures from spreading by blocking the flow of signals from the central nervous system (CNS) rather than raise the threshold for seizures. All CNS depressants, including anticonvulsants, can cause depression.
Alternatives: For seizures, phenytoin (Dilantin), which raises the seizure threshold; for chronic neuropathic pain, venlafaxine (Effexor), which affects the two neurotransmitters, serotonin and norepinephrine, that are thought to play roles in regulating pain.
8. Proton pump inhibitors and H2 blockers
Why they're prescribed: Doctors typically prescribe these medications, which suppress the secretion of gastric acid, to treat gastroesophageal reflux disease (GERD).
How they can cause depression: While these drugs are known to cause depression, scientists don't yet understand why they do. When any major body process is blocked, however, the body often rebels in an intense effort to fight back. Consequently, it's altogether likely that changing the pH of the stomach could bring on changes to the central nervous system and the brain.
Alternatives: Know which foods trigger your acid reflux (spicy or fried foods, for example) and avoid them, especially in the hours before bedtime. A non-calcium-carbonate-based antacid, such as Mylanta, may also help. Many of my patients have reported relief from the home remedy of apple cider vinegar and honey (typically one tablespoon each, taken together), though I know of no scientific research that confirms the effectiveness of this approach.
9. Statins and other lipid-lowering drugs
Why they're prescribed: Statins are the class of drugs most commonly prescribed to lower cholesterol levels, followed by fibrates and other drugs, such as ezetimibe, colesevelam and nicotinic acid.
How they can cause depression: Recent research suggests that lipid-lowering drugs may cause depression by depleting levels of cholesterol in the brain, where it plays an important role in the release of neurotransmitters.
Alternatives: A combination of vitamin B12 (injectable or sublingual), vitamin B6, folic acid and fish oil can lower homocysteine levels in the body. Homocysteine, an amino acid, inflicts damage to the inner arterial lining (endothelium) and other cells of the body, elevating lipids levels. While there are many studies that substantiate this nondrug approach and many that reject it, I've found that it works consistently well in older patients without posing the risk of serious side effects.
10. Anticholinergic drugs used to treat stomach cramps and other GI disorders
Why they're prescribed: Anticholinergic medications slow the action of the intestine, thereby reducing the amount of stomach acid produced. They do this mostly by blocking the effects of acetylcholine, the neurotransmitter that causes muscles — including those in the intestine — to contract. Dicyclomine (Bentyl), for example, is widely used to treat the symptoms of irritable bowel syndrome.
How they can cause depression: Anticholinergics, as central nervous system depressants, can cause depression, sedation and cognitive impairment in older patients.
Alternatives: Using an H2 blocker such as ranitidine (Zantac) in the lower-dose formulation (75mg) can work well for the occasional attack of heartburn and acid indigestion. A calcium-free antacid (Gelusil or Mylanta, for example) may help.