Selective Serotonin Reuptake Inhibitor ( SSRI ) Drugs : More Risks Than Benefits ?

Anecdotal reports have suggested that selective serotonin reuptake inhibitors (SSRIs) may cause suicidal or violent behavior in some patients. Because of the publicity surrounding certain events, and the numerous lawsuits that have been filed, a review of benefits and risks is needed. At most 30% of patients receive a benefit from SSRIs beyond the large placebo effect in certain mental conditions, especially depression, according to a recent meta-analysis of published trials. An equally recent meta-analysis of all SSRI trials submitted to the FDA showed a small benefit for the severely depressed patients only. Many early unpublished trials did not show any benefit. Adverse effects are common, occurring in up to 75% of subjects. Severe adverse effects may be underreported. Metaanalyses of controlled trials did not include any actual suicides or murders, but only suicidality, some finding, in 1991 and 2007, no evidence even of suicidality. Other meta-analyses using many of the same trials found that suicidality doubled to 1 in 500 on SSRIs compared with placebo or non-SSRI antidepressants, but did not include any actual suicides or murders. The trial designs were devised by SSRI makers to prevent reports of suicides, by eliminating subjects with the slightest trace of suicidal tendencies. Retrospective studies by others showed actual suicides on SSRIs with a relative risk (RR) of 2–3 compared with non-SSRI antidepressants, with an increased incidence of 123/100,000. Lower doses than the smallest available ones were found to maintain benefits in a majority of patients while reducing risks. No causal connection between SSRIs and suicide and/or violence has been proved; neither has it been ruled out. Physicians need to be vigilant, and aware of legal precedents that may subject them to enhanced liability when prescribing these drugs. The Genesis of SSRIs Fluoxetine (Prozac in the U.S., see Table 1), introduced in 1988 to combat depression, was the fourth selective serotonin reuptake inhibitor (SSRI) on the U.S. market, after being seriously considered by Eli Lilly as an antihypertensive drug. Unlike the earlier “tricyclics” (amitripyline, clomipramine, dothiepin, imipramine, etc.) and other drug classes, SSRIs acted on the brain to raise levels of the neurotransmitter serotonin without raising the levels of norepinephrine. This was thought to be a benefit in treatment of depression, and later anxiety, panic, social phobia, obsessive-compulsive disorder (OCD), and many other conditions. The SSRIs listed in Table 1 are among the most frequently prescribed in the U.S., and compete with the five nonSSRIs shown, and others. 1 Benefits of SSRIs A prominent recent meta-analysis of Bridge et al. included 27 trials of SSRIs for three defined mental conditions: major depressive disorder (MDD),OCD, and non-OCDanxiety disorders. Benefits, compared with placebo, were found to be highly statistically significant. For MDD, data from 13 trials showed benefit in 61% vs. 50% on placebo, a gain of 11% absolute (NNT=10), <0.001 for all ages of participants. For OCD, data from six trials showed benefit in 52% vs. 32% on placebo, a gain of 20% absolute (NNT=5), <0.001 for all ages. For non-OCD anxiety, data from 6 trials showed benefit in 69% vs. 39% on placebo, a gain of 30% absolute (NNT=3), <0.001 for all ages. These results represent the maximum expectation of benefit from SSRIs since 22 of the 27 trials were financially supported by SSRImakers, and thus subject to the routinely positive bias of industry-sponsored clinical trials. Jay S. Cohen,M.D., author of the 2001 book , wrote that half his patients did well on fluoxetine, but he noted a high incidence (50%) with side-effects. Cohen also cited a pre-approval study showing that the standard 20mg per day starting dose helped 65% of patients, while 5 mg helped 54%, soCohen became one of the pioneers in using lower doses before Lilly made them available. The 1996 entry for paroxetine, at least, confirmed that the 17 most common side-effectswere dose-dependent. In four observational cohort studies of four common SSRIs reported by physicians as part of the prescription-event monitoring program in the UK, with more than 10,000 patients in each drug group, only 36%of the physicians reported fluvoxamine as effective, compared with 60% for fluoxetine, sertraline, and paroxetine. These possible benefit rates, which include the placebo effect, parallel the percentage of patients remaining on the drug for 2months. 2