Seasonal Affective Disorder and Ketamine:
Timing Treatments for Year-Round Mental Health

What is seasonal affective disorder, and who does it affect?

Seasonal affective disorder is a form of major depression that follows a predictable seasonal pattern. For most people, symptoms arrive in late fall or early winter and lift in spring. A smaller number experience a summer-onset pattern, though winter SAD is far more common.

The hallmarks often include persistent low mood, loss of interest in activities that once felt rewarding, fatigue that sleep does not resolve, difficulty concentrating, social withdrawal, changes in appetite (often carbohydrate cravings), and a heavy, leaden feeling in the limbs.

SAD is more than "winter blues." It meets the full diagnostic criteria for major depressive disorder, and for many people it is genuinely disabling. Research suggests that reduced sunlight disrupts circadian rhythms, lowers serotonin activity, and alters melatonin production — creating a neurochemical environment that makes depression more likely.

Here in Nashville, we may not face the extreme darkness of northern latitudes, but the shorter days and overcast stretches of Tennessee winters are enough to trigger SAD in susceptible individuals. Women, younger adults, and those with a personal or family history of depression appear to be at higher risk.

Why do traditional SAD treatments sometimes fall short?

The standard approaches to seasonal affective disorder — light therapy, SSRIs, SNRIs, talk therapy — help a significant number of people. We would never suggest otherwise. But they do not work for everyone, and some patients cycle through the same frustrating pattern year after year.

Light therapy requires consistent daily use, often 20 to 30 minutes each morning, and its effects can take weeks to build. Some people find the time commitment difficult to sustain, especially when the fatigue of SAD itself makes mornings feel insurmountable.

Antidepressants typically need four to eight weeks to reach full effect. For someone whose depressive window is three to four months, that delay can consume a large portion of the season. And if the medication chosen does not work well, there may not be enough time in the cycle to try another.

Psychotherapy, particularly cognitive behavioral therapy adapted for SAD (CBT-SAD), has solid evidence behind it. Yet access to a trained therapist, cost, and scheduling can create barriers — especially during the very months when motivation is lowest.

None of these limitations make these treatments bad. They simply mean that some people need an additional option, or a different pathway altogether.

How can ketamine therapy help with seasonal depression?

Ketamine works through a fundamentally different mechanism than traditional antidepressants. Rather than targeting serotonin or norepinephrine, it modulates the glutamate system — the brain's most abundant excitatory neurotransmitter. This triggers a cascade that includes increased brain-derived neurotrophic factor (BDNF) and rapid formation of new synaptic connections, a process known as neuroplasticity.

For seasonal affective disorder specifically, this mechanism is promising for several reasons:

• Speed of response. Research suggests that many patients notice a shift in mood within hours to days of their first infusion, rather than the weeks required by SSRIs. When your depressive window is finite, speed matters.
• Neuroplastic support. SAD involves the same synaptic density reductions seen in other forms of depression. Ketamine's ability to promote rapid synaptogenesis may help restore connections that seasonal shifts have weakened.
• Complementary pathway. Because ketamine targets glutamate rather than serotonin, it can often be used alongside existing medications and light therapy, potentially filling gaps that other treatments leave.
• Disrupting the cycle. For people who experience the same depressive pattern year after year, ketamine may help interrupt that cycle at a neurobiological level, rather than simply managing symptoms after they arrive.

We want to be clear: ketamine is not a cure for SAD, and research into its specific application for seasonal depression is still evolving. What we can say is that the broader evidence for ketamine in treatment-resistant depression is substantial, and many of our patients with seasonal patterns have reported meaningful improvement.

When should you start ketamine treatment for SAD?

This may be the most important question in the article, and the answer often surprises people: consider starting before your symptoms arrive.

Most people with SAD know their pattern. You know the month when the weight begins to settle. You know the week when getting out of bed becomes a negotiation. That predictability, while exhausting, is also an opportunity.

Proactive vs. reactive treatment

A reactive approach means waiting until symptoms are already present before seeking treatment. This is how most people engage with SAD care, and it works — but it means you spend weeks or months in the grip of depression before relief begins.

A proactive approach means beginning ketamine infusions in early to mid-fall, before the worst of your symptoms take hold. The goal is to build neuroplastic resilience ahead of your vulnerable window, so your brain enters the season in a stronger position.

Think of it as strengthening the foundation before the storm, rather than repairing damage after it passes.

For many patients, a proactive initial series in September or October, followed by maintenance sessions as needed through winter, provides more consistent relief than waiting until December or January when symptoms have already peaked.

Patients who also use light therapy or antidepressants can continue those alongside ketamine. In fact, combining approaches — ketamine for rapid neuroplastic support, light therapy for circadian rhythm regulation, and therapy for cognitive patterns — may offer the most comprehensive coverage. We coordinate with your existing providers whenever possible.

What a treatment plan looks like at Music City Ketamine

Every patient's experience with seasonal affective disorder is different, and we build your plan accordingly. Here is what you can generally expect.

Initial conversation. We start with a thorough discussion of your history — how long you have experienced SAD, what you have tried, your seasonal timeline, your current medications, and your goals. This is a conversation, not a sales pitch. If we do not think ketamine is right for your situation, we will tell you.

Initial series. The typical protocol involves six IV ketamine infusions over two to three weeks. Each session lasts roughly 45 to 60 minutes. You will be monitored throughout by Marla Peterson, CRNA — a certified registered nurse anesthetist with advanced training in anesthesia and patient safety.

Maintenance. After the initial series, many patients with SAD benefit from periodic maintenance infusions through the winter months. The frequency varies — some people do well with monthly sessions, others may need them every two to three weeks during their most vulnerable period.

Integration. We encourage every patient to have a therapist or counselor they are working with. The neuroplastic window that opens after each infusion is a valuable period for therapeutic work, and having professional support during that time can amplify the benefits of treatment.

You do not have to dread the season

If you have spent years watching the calendar with a quiet sense of dread, knowing what is coming and feeling powerless to stop it — we understand. And we want you to know that there are options beyond what you may have already tried.

A conversation with our team costs nothing and commits you to nothing. We will listen to your story, review your history, and give you an honest assessment of whether ketamine therapy might help with your seasonal pattern. If it is not the right fit, we will tell you that, too.

You deserve to live fully through every month of the year.

Warmly,
Marla Peterson, CRNA — and the Music City Ketamine team