Last time I discussed basic information about major depressive disorder, which is also known as a clinical depression. I discussed how it is different than grieving, has a genetic predisposition, may affect people from all walks of life and should be taken seriously, by getting a thorough evaluation, which may include a physical exam, to ensure that some general medical condition isn’t also involved.

This week’s column will focus on various treatments available for these depressive disorders. I will be focusing on major depressive disorder, which is the most common. Bipolar disorder is a different condition, requiring different treatments.

There are three main categories of treatments: medications, somatic treatments and psychotherapies.

We base the treatment for any condition — general medical, psychiatric or surgical — on what our understanding is of what is causing the condition. In the case of depressive disorders, our current understanding is that there is dysregulation in various circuits throughout the brain that produces the symptoms we feel.

Given that the brain works via electricity propagating down a nerve cell and then various chemicals, called neurotransmitters, that jump the synapse, or space between cells, to form hundreds of millions of circuits, it is reasonable to attempt to treat various brain disorders by attempting to correct dysfunctional nerve transmission.

Given that there are clear genetic vulnerabilities to these conditions, and we don’t yet have the technology for gene repairs, we do our best to restore healthy nerve function with medications that target the neurotransmitters that appear to be involved with depressive disorders. In these cases, neurotransmitters such as serotonin, dopamine and norepinephrine are commonly targeted, improving depressive symptoms.

More recently, ketamine derivatives have been approved as nasal sprays and can be helpful when treating certain depressive disorders.

When we use antibiotics to treat ear infections, we don’t suggest that an ear infection is caused by a lack of antibiotics. I am not suggesting that depressive disorders are necessarily caused by a lack of these neurotransmitters but, rather, that is where we can target effective treatment.

The most common medications used to treat depressive disorders affect serotonin, or serotonin and norepinephrine. They are almost all available generically now and are relatively affordable.

It usually takes two to four weeks to notice clear improvement, as these medications increase and restore nerve growth in various parts of the brain, and nerve growth takes some time.

Side effects are generally mild and fade away, with the exception of some sexual side effects. Those can be readily treated, but do exist. Discontinuation syndromes may happen if a person abruptly stops these medications. We recommend tapering slowly.

Depending on family and personal history, these medications may be taken for a relatively brief period, such as six months to a year, or, for some people, a lifetime. Obviously, this is something to be discussed with a person’s treating physician.

Probably the most important consideration in treating depressive disorders is to appreciate that the majority of treatment for psychiatric conditions is done by nonpsychiatric physicians and, while they diagnose well and choose good medications, they sometimes are reticent to increase the medications to full therapeutic doses.

It’s important that each person receive optimal care, which needs to be individualized.

I plan to discuss the various kinds of medications and other treatments next time.

Alan Koenigsberg, M.D., is a practicing psychiatrist and clinical professor of psychiatry at UTSW Medical School in Dallas.