| Antidepressants are used commonly in medical | | | | to SSRls, MAOls, TCAs, and high-potency |
| and psychiatric practice. As a class, | | | | benzodiazepines (alprazolam and clonazepam).OCD |
| antidepressants have in common their ability to | | | | has been shown to respond to the |
| treat major depressive illness. Most | | | | serotonin-selective tricyclic clomipramine (Anafranil) |
| antidepressants are also effective in the | | | | and to SSRIs at high doses (e.g., fluoxetine at |
| treatment of panic disorder and other anxiety | | | | 60-80mg/ day). Obsessions tend to be more |
| disorders. Some antidepressants effectively treat | | | | responsive to pharmacotherapy than compulsions. |
| obsessive-compulsive disorder (OCD) and a | | | | Symptoms of OCD respond more slowly than |
| variety of other conditions (see indications | | | | symptoms of major depression. Trials of 12 |
| below).The most commonly prescribed | | | | weeks or more are needed before a medication |
| antidepressants are listed in Table 12-1. | | | | can be ruled a failure for an OCD patient.The |
| Antidepressants are subdivided into groups based | | | | binging and purging behavior of bulimia has been |
| on structure or prominent functional activity: | | | | shown to respond to SSRls, TCAs, and MAOls in |
| selective serotonin reuptake inhibitors (SSRls), | | | | several open and controlled trials. Because SSRIs |
| tricyclic antidepressants (TCAs), monoamine | | | | have the most benign side-effect profile of these |
| oxidase inhibitors (MAOls), and other | | | | medications, they are often the first-line |
| antidepressant compounds with a variety of | | | | psychopharmacologic treatment.Mechanisms of |
| mechanisms of action. Antidepressants are | | | | ActionAntidepressants are thought to exert their |
| typically thought to act on either the serotonin or | | | | effects at particular subsets of neuronal synapses |
| norepinephrine systems, or both. Choice of | | | | throughout the brain. Their major interaction is |
| medications typically depends on diagnosis, history | | | | with the monoamine neurotransmitter systems |
| of response (in patient or relative), and the | | | | (dopamine, norepinephrine, and serotonin). |
| side-effect profile of the medication. | | | | Dopamine, norepinephrine, and serotonin are |
| Antidepressant effects are typically not seen until | | | | released throughout the brain by neurons that |
| 2 to 4 weeks into treatment. Side effects must | | | | originate in the ventral brainstem, locus ceruleus |
| be carefully monitored, especially for TCAs and | | | | and the raphe nuclei, respectively. These |
| MAOls.IndicationsTable 12-2 lists the indications for | | | | neurotransmitters interact with numerous |
| antidepressants. | | | | receptor subtypes in the brain that are associated |
| The main indication for antidepressant | | | | with the regulation of global state functions |
| medications is major depressive disorder as | | | | including appetite, mood states, arousal, vigilance, |
| defined by the Diagnostic and Statistical Manual of | | | | attention, and sensory processing.SSRls act by |
| Mental Disorders, 4th edition (DSM-IV). | | | | binding to presynaptic serotonin reuptake proteins, |
| Antidepressants are used in the treatment of all | | | | thereby inhibiting reuptake and increasing the |
| subtypes of depression, including depressed phase | | | | levels of serotonin in the synaptic cleft.TCAs act |
| of bipolar disorder, psychotic depression (in | | | | by blocking presynaptic reuptake of both |
| combination with an antipsychotic medication), | | | | serotonin and norepinephrine. MAOls act by |
| atypical depression, and seasonal depression. | | | | inhibiting the presynaptic enzyme (monoamine |
| Antidepressants also are indicated for the | | | | oxidase) that catabolizes norepinephrine, dopamine, |
| prevention of recurrent depressive | | | | and serotonin, thereby increasing the levels of |
| episodes.Antidepressant medications may be | | | | these neurotransmitters presynaptically.These |
| effective in the treatment of patients with | | | | immediate mechanisms of action are not sufficient |
| dysthymic disorder, especially when there are | | | | to explain the delayed antidepressant effects |
| clear neurovegetative signs or a history of | | | | (typically 2 to 4 weeks). Other unknown |
| response to antidepressants.Panic disorder with or | | | | mechanisms must play a role in the successful |
| without agoraphobia has been shown to respond | | | | psychopharmacologic treatment of depression. |