What is OCD?

OCD is a mildly to severely disabling illness that afflicts approximately 2-3% of the general population. Unfortunately, OCD is often underdiagnosed or undertreated. Patients may be embarrassed about their illness, or lack insight, and so may not seek treatment. Furthermore, clinicians often do not recognize or ask about OCD symptoms. Some clinicians who see OCD patients might not be properly educated with regard to effective OCD treatments. Clinical studies support the effectiveness of both behavioral therapy and medications for OCD. The combination of these two treatments offers the best possible treatment outcome.

Which medications can be helpful for OCD?

Typically, OCD is treated with antidepressants. The ones used for OCD are called antiobsessional medications, since they predominantly work by reducing the frequency and intensity of obsessions, thereby reducing the urge to engage compulsive behaviors. Clinical studies have shown that a certain anti-depressants, known as serotonin reuptake inhibitors (SRIs), are most helpful for OCD. The six SRIs that have been shown to be effective in such studies include: fluvoxamine (Luvox), fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), citalopram (Celexa), and clomipramine (Anafranil). Lexapro, a relatively newer medication, is very similar to Celexa, and is likely also helpful for OCD. While all of these medications are SRIs, all except for Anafranil are known as SSRIs (selective serotonin reuptake inhibitors). Whereas Anafranil has been in use for a far longer time and has been the most extensively studied, there is growing evidence that the SSRIs are equally effective for OCD. More than half of patients with OCD suffer from depression, which is often treatable with the very same medication they are taking for their OCD.

Do all antidepressants help OCD symptoms?

In clinical studies, only the SRIs have shown to be effective for OCD. Some commonly used antidepressants have little or no effect on serotonin in the brain. As such, they have not been shown to be helpful for OCD symptoms. Good anti-depressants, such as imipramine (Tofranil), amitriptyline (Elavil), or buproprion (Wellbutrin), only rarely improve OCD symptoms.

How do we know these drugs are effective?

The SRIs have been shown to be useful for OCD in double-blinded clinical studies. In these studies, two groups of OCD patients are compared with regard to their response to the drug being tested as compared to an inactive placebo. Neither the patients nor the clinicians know which group is receiving the active medication or the placebo. In addition to these carefully studied drugs, there are growing reports and promising preliminary studies suggesting that venlafaxine (Effexor) may also be an effective medication for OCD, however, to date there have been no large-scale double-blinded studies conducted with this drug. Also, a multitude of case reports and some relatively inconclusive studies suggest that numerous other drugs, including over-the-counter medications, might also be helpful for OCD.

Why are these drugs effective for OCD?

It remains unclear as to why these particular drugs help OCD while similar drugs do not.  The SRIs influence the activity of serotonin, a chemical messenger in the brain. The treatment response in OCD appears to be due, in part, to the potent effect on brain serotonin by relatively high doses of SRIs.  Abnormalities with brain serotonin activity are also associated with depression, which appears to be the reason why SRIs are effective for both disorders. Of note, it is very likely that other brain chemicals in addition to serotonin are involved in OCD. This might be the reason that there is some evidence for non-SRI drugs showing benefit for OCD.

At what dosages are these medications used?

Typically, it appears that for most patients high dosages of these drugs are required for effective treatment.  The studies done todate suggest that the following dosages may be necessary:  Luvox (up to 300 mg/day), Prozac (up to 80 mg/day), Zoloft (up to 200mg/day), Paxil (up to 60 mg/day), Celexa (up to 80 mg/day), Anafranil(up to 250 mg/day), and Effexor (up to 375mg/day). It should be noted that Effexor’s SRI activity is stronger at the higher doses, making it more likely that a relatively high dose will be needed for OCD.

Are there side effects?

Each of these drugs has side effects, and it is quite unusual for an individual patient not to have one or more side effects. As with all drugs, the patient and physician must weigh the benefits of the drug against the side effects. Sometimes just an adjustment in dosage or switch in the time of day that one takes the medication is all that is required. Typically, the side effects lessen over time.

All of the SRIs commonly produce sexual side effects in both sexes that may range from lowering of sexual drive to delayed ability to have an orgasm to complete inability to have an erection or orgasm. Occasional patients report increased interest in sexual activity. Paxil has been observed to produce sexual side effects (and also weight gain) much more often than the other SRIs. These drugs also commonly cause nausea, inability to sit still, sleepiness in some individuals, insomnia in others, and a heightened sense of energy. Anafranil may also cause pronounced effects like drowsiness, dry mouth, racing heart, memory problems, concentration difficulties, and problems with urination (mostly in men).  Sometimes weight gain is a problem and a strict diet may be needed if appetite is increased. There are many other less common side effects with these drugs that your physician may discuss with you. As a general rule, these drugs are very safe, even with long-term use; and all of the side effects completely reverse when the drugs are stopped. There is no evidence that they do permanent damage to the body.
 
How long does it take antiobsessional medications to take effect?

It is important not to give up on a medication until you have been taking it at a therapeutic dose for 10 to 12 weeks. Many patients feel no positive effects for the first few weeks of treatment, but then they may improve greatly. Typically, if patients have side effects, they will experience them before noticing positive results from the drug. We do not know why the medications take so long to work for OCD. 

How helpful should I expect these medications to be?

In the large studies that have been done, each medication helps about 75% to 85% of the patients at least a little. About 50% to 60% of patients have at least a moderate response to medication. Some patients have no response at all. If a patient does not respond to the first medication, they might still have a profound benefit from a different one. There are also techniques of combining medications that might improve the response.

What is augmentation therapy?

The best augmenting technique is to add behavior therapy to ongoing drug treatment. However, to enhance the activity of anantiobsessional drug, we sometimes combine two or more medications together. When used in conjunction with SSRIs, the class of medications that has shown the most efficacy for OCD is the neuroleptics. We prefer to prescribe the more recent “atypical” neuroleptics, since they have a lower side effect profile. Risperidone (Risperdal) has been the most extensively studied of these for OCD, but there is also evidence to support the use of Olanzapine (Zyprexa), and quetiapine (Seroquel) for augmentation. For many patients who do not respond to SRIs alone, they might expect to see a significant improvement in their OCD within four weeks with one of these medications. As with all medications, the decision to use neuroleptics should be made after a comprehensive discussion about side effects.

Also, some people respond to combining an SSRI with Anafranil. It is important for the physician to keep in mind that Anafranil’s blood level can be dramatically increased by adding one of the other drugs.

Other drugs are sometimes combined with ongoing SRI medications. Some that have commonly been used include: buspirone (BuSpar), lithium carbonate (Eskalith), clonazepam (Klonopin), methylphenidate (Ritalin), gabapentin (Neurontin), and other antidepressants (eg, trazodone, bupropion, desipramine, etc). The controlled trials that have been done with these augmenting agents have been generally unconvincing. But since occasional patients respond to the addition of a second drug, clinicians frequently try this technique.

Who should not take antiobsessional medications?

In general, we try not to give antiobsessional medications to women who are pregnant or are breast feeding, given that we do not clearly understand the long-term effects of these drugs on a fetus or infant. If severe OCD cannot be controlled any other way, however, these medications seem to be safe and many pregnant women have taken them without difficulty. If there were risk to the fetus, it is likely that most of the risk would be during the first 3 months of pregnancy. Some OCD patients are able to use the behavioral techniques of exposure and response prevention to avoid medications at least during the initial 3 months of pregnancy. If the OCD is very severe, one may need to take medication throughout the course of pregnancy.

In very elderly patients, it is best to avoid Anafranil as an initial drug since it has side effects that can interfere with thinking or cause confusion.  Some of the other antiobsessional drugs like Prozac, Zoloft, Luvox, Celexa and Paxil can be used in the elderly, but greatly reduced dosages are often required, generally due to metabolic differences in the elderly. Although these drugs can be taken by patients with heart disorders, special precautions are required, such as close monitoring with electrocardiograms (ECGs).

How long does one need to stay on antiobsessional medications?

It is unclear just how long patients should continue to take these medications once they have been effective.  Some patients are able to discontinue medications after a 6 to 12-month treatment period. However, it does appear that over half of OCD patients (and maybe many more) will need to be on at least a low dosage of medication for years, perhaps even for life. In terms of reducing the need for medications, it is often helpful to learn to use behavior therapy techniques while doing well on medication, and especially if medication is reduced very slowly (even over many months). The behavioral techniques may enable patients to control any symptoms that return when they stop taking medication. Typically, after medications are stopped, symptoms do not return immediately, but may start to return within a few weeks to a few months. The vast majority of patients who relapse after the cessation of an effective medication will have a good response when they resume taking the drug.