As daylight wanes and evenings grow longer, many people notice a shift in mood and energy. For a segment of the population, the change signals the onset of seasonal affective disorder (SAD), a form of depression that typically emerges in the fall and winter months. Experts say symptoms can include low energy, altered sleep patterns, carbohydrate cravings and a pervasive sense of hopelessness.
Prevalence and Geographic Variation
Research estimates that about five percent of Americans experience SAD, though professionals acknowledge that the figure may be an underestimate because many sufferers remain silent until the condition eases with warmer weather. Geographic location appears to influence risk. In Florida, a state known for its abundant sunshine, roughly one percent of residents are thought to have the disorder, whereas in New Hampshire, situated farther from the equator, the prevalence rises to about ten percent.
Causes and Diagnosis
The disorder was named in the 1980s by Dr. Norman Rosenthal, who observed his own mood shifts after moving from South Africa to the United States. While no single cause has been identified, reduced sunlight exposure is considered a primary factor. A lack of natural light can disrupt circadian rhythms, leading to sleep disturbances and altered serotonin levels, both of which are linked to mood regulation.
Physicians typically diagnose SAD after confirming that depressive episodes recur in a seasonal pattern for at least two consecutive years. Dr. Robin Tassinari, a professor of psychiatry and internal medicine at Albany Medical Center and Albany Medical College, emphasizes that sunlight helps maintain serotonin levels and supports healthy sleep cycles.
Treatment Options
Management strategies focus on increasing exposure to natural light and bolstering social interaction during the darker months. Christopher Fisher, director of behavioral health at Northwell Health’s Zucker Hillside Hospital, notes that outdoor activity can stimulate dopamine release, boosting motivation and mood.
Light therapy is a widely used intervention. Commercial light boxes deliver up to 10,000 lux—comparable to a bright spring day—and are priced between approximately $70 and $200. Patients sit near the device for a prescribed duration each morning, mimicking natural sunlight.
Psychotherapy, particularly cognitive behavioral therapy (CBT), is often combined with light exposure. Dr. Ronald Brenner, chief of the behavioral health service line at Catholic Health, describes the combined approach of light therapy, CBT and, when appropriate, antidepressant medication as the most effective way to treat SAD.
In addition to clinical treatments, mental health professionals encourage proactive planning. “You don’t have to accept four to five months of feeling slumped,” Fisher says. “We can be proactive, plan, and strategize to avoid a drastic hit to our mood.”
Overall, recognizing the seasonal pattern of symptoms, seeking professional evaluation, and employing a multi‑modal treatment plan can help individuals maintain well‑being throughout the darker months.
Steve Lopez is a Senior Editorial Columnist and Health & Public Policy reporter for News Raise. Steve focuses on healthcare advancements, medical technologies, and public health policies.
