Antidepressants and Phototherapy

Antidepressants are used commonly in medicalto SSRls, MAOls, TCAs, and high-potency
and psychiatric practice. As a class,benzodiazepines (alprazolam and clonazepam).OCD
antidepressants have in common their ability tohas been shown to respond to the
treat major depressive illness. Mostserotonin-selective tricyclic clomipramine (Anafranil)
antidepressants are also effective in theand to SSRIs at high doses (e.g., fluoxetine at
treatment of panic disorder and other anxiety60-80mg/ day). Obsessions tend to be more
disorders. Some antidepressants effectively treatresponsive to pharmacotherapy than compulsions.
obsessive-compulsive disorder (OCD) and aSymptoms of OCD respond more slowly than
variety of other conditions (see indicationssymptoms of major depression. Trials of 12
below).The most commonly prescribedweeks 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 basedbinging 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), monoaminehave the most benign side-effect profile of these
oxidase inhibitors (MAOls), and othermedications, they are often the first-line
antidepressant compounds with a variety ofpsychopharmacologic treatment.Mechanisms of
mechanisms of action. Antidepressants areActionAntidepressants are thought to exert their
typically thought to act on either the serotonin oreffects at particular subsets of neuronal synapses
norepinephrine systems, or both. Choice ofthroughout the brain. Their major interaction is
medications typically depends on diagnosis, historywith 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 untilreleased throughout the brain by neurons that
2 to 4 weeks into treatment. Side effects mustoriginate in the ventral brainstem, locus ceruleus
be carefully monitored, especially for TCAs andand the raphe nuclei, respectively. These
MAOls.IndicationsTable 12-2 lists the indications forneurotransmitters interact with numerous
antidepressants.receptor subtypes in the brain that are associated
The main indication for antidepressantwith the regulation of global state functions
medications is major depressive disorder asincluding appetite, mood states, arousal, vigilance,
defined by the Diagnostic and Statistical Manual ofattention, 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 allthereby inhibiting reuptake and increasing the
subtypes of depression, including depressed phaselevels of serotonin in the synaptic cleft.TCAs act
of bipolar disorder, psychotic depression (inby 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 theoxidase) that catabolizes norepinephrine, dopamine,
prevention of recurrent depressiveand serotonin, thereby increasing the levels of
episodes.Antidepressant medications may bethese neurotransmitters presynaptically.These
effective in the treatment of patients withimmediate mechanisms of action are not sufficient
dysthymic disorder, especially when there areto 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 ormechanisms must play a role in the successful
without agoraphobia has been shown to respondpsychopharmacologic treatment of depression.