Geriatric Depression and its treatment: Medication
Treatments for Major Depression
Let’s move to a discussion of medication for depression in the senior population.
Antidepressant medication first became available in the 1950s with the introduction of the tricyclic imipramine. Since then, numerous agents have become available in the United States.
A detailed discussion of the mechanism of action of these drugs is well beyond the scope of this blog, but briefly, antidepressants act in complex ways on one or more of the following three neurotransmitters- serotonin, norepinephrine, and dopamine. I share with patients that there are two main classes of antidepressants- the selective serotonin reuptake inhibitors (SSRIs), which include well known drugs like Prozac, Zoloft, Lexapro, Celexa, and Paxil (all trade names), and the serotonin-norepinephrine reuptake inhibitors (SNRIs), including Effexor, Cymbalta, and Pristiq. There are a variety of other medications, including Wellbutrin, Remeron, newer agents such as Trintellix, Viibryd, Fetzima, and older but still very effective agents such as the tricyclics and the monoamine oxidase inhibitors (MAOIs).
Medications have different potential side effect profiles. Queasiness, jitteriness, constipation, sexual dysfunction, sedation, insomnia, and effects on heart rhythm are amongst the most common. Geriatric psychiatrists are highly trained not only to choose the most appropriate medication for a senior, but also can assess the patient’s current ‘medical medication’ list for potential interactions and whether currently prescribed medications could be contributing to depression.
There is a concept in the treatment of depression known as augmentation. In the context of depression, an augmentation agent is a medication that is not in and of itself an antidepressant, but when used in conjunction- ie to augment- an antidepressant, the additional medication can often help the treat depressive symptoms more completely. Examples of augmentation agents are low dose lithum, the antipsychotics Abilify and Rexulti, and thyroid hormone.
Medication therapy for depression tends to be effective about 70% of the time. However, in the event a given medication is ineffective, psychiatrists will move on to try other agents, often yielding a positive response. In a future blog, I plan on talking about what constitutes an adequate trial of an antidepressant.
Finally, other medications used in the treatment of depression include sedative hypnotics for insomnia, antianxiety medications, and occasionally, if the patient is suffering a severe form of depression with psychosis, antipsychotics.
In the next blog, I will move on the discuss newer treatments for depression, transcranial magnetic stimulation (TMS) and ketamine.