Selective serotonin reuptake inhibitors (SSRIs) are the first-line intervention for many psychiatric disorders including major depressive disorder (MDD) and generalized anxiety disorder (GAD). These drugs work by inhibiting the reuptake of serotonin leading to increased serotonin transmission. Enhanced serotonin transmission improves mood and personality. The Food and Drugs Administration (FDA) has approved several SSRIs for treating depression in adolescents and adults. These drugs include fluoxetine, sertraline, citalopram, and paroxetine. Some of these drugs are also approved for treating GAD.
Patients diagnosed with MDD exhibit a persistent pattern of low mood and loss of interest in usual activities (anhedonia). The common characteristics of low mood include persistent feelings of sadness, emptiness, or worthlessness. Other common symptoms of depression include sleeping difficulties, persistent fatigue or lack of energy, poor appetite, frequent anger outbursts, and impaired thinking and concentration. On the other hand, patients with GAD exhibit a persistent pattern of excessive worrying and anxiety regarding everyday activities. A person with GAD will exhibit restlessness, difficulty concentrating, indecisiveness, and perceiving usual situations as threatening.
Fluoxetine (Prozac) and Sertraline (Zoloft) are commonly prescribed to treat MDD and GAD, respectively. For depression, the recommended fluoxetine starting dose is 20mg taken once daily. The daily dose should not exceed 80mg. The therapeutic range for many is between 20 and 40 mg/day. The primary goal of treatment is for the patient to attain at least a 50 percent reduction of the core depressive symptoms or complete remission. For GAD, the recommended sertraline starting dose is 25 mg once daily for adults. Dose increments of between 25 and 50mg/day at weekly intervals to a maximum of 200mg/day may be necessary to achieve optimal therapeutic gains.
Patients taking SSRIs either for depression or anxiety should expect a delay of between 2 to 4 weeks before they can experience the therapeutic benefits of the drugs. Some patients may require subsequent dose increments before they can achieve optimal therapeutic gains. Patients who have not attained any significant therapeutic gains by 6 to 8 weeks of treatment should discuss with their health care provider the need for an augmenting therapy or switching to a different psychopharmacological agent.
The common side effects of SSRIs include insomnia, gastrointestinal disturbance characterized by nausea, diarrhea, and dry mouth, sexual dysfunction, and central nervous problems including headaches, sedation agitation, and dizziness. Although adverse side effects are rare, some patients may develop seizures and activation of mania and suicidal thoughts. Antidepressants can aggravate suicidal behavior, especially in adolescent patients. For additional information on psychopharmacology for mental health disorders, visit