Reference Terms
from Wikipedia, the free encyclopedia
Seasonal affective disorder
Seasonal affective disorder, or SAD, also known as winter depression is an affective, or mood disorder. Most SAD sufferers experience normal mental health throughout most of the year, but experience depressive symptoms in the winter or summer. SAD is rare, if existent at all, in the tropics, but is measurably present at latitudes of 30 degrees N (or S) and higher. Seasonal mood variations are believed to be related mostly to daylight, not temperature. For this reason, SAD is prevalent even in mid-latitude places with mild winters, such as Seattle and Vancouver. People who live in the Arctic region are especially susceptible due to the effects of polar nights. Prolonged periods of overcast weather can also exacerbate SAD. SAD is a serious disorder, sometimes triggering dysthymia or clinical depression. A number of treatments exist for SAD. These include light therapies, medication, ionized-air reception and cognitive therapy.
Related Stories
1
2
Mind & Brain News
January 26, 2026
Jan. 26, 2026 Alzheimer’s may destroy memory by flipping a single molecular switch that tells neurons to prune their own connections. Researchers found that both amyloid beta and inflammation converge on the same receptor, triggering synapse loss. Surprisingly, ...
Jan. 25, 2026 A massive new study comparing more than 100,000 people with today’s most advanced AI systems delivers a surprising result: generative AI can now beat the average human on certain creativity tests. Models like GPT-4 showed strong performance on ...
Jan. 25, 2026 Researchers have found that a natural aging-related molecule can repair key memory processes affected by Alzheimer’s disease. The compound improves communication between brain cells and restores early memory abilities that typically fade first. ...
Jan. 24, 2026 People with spinal cord injuries often lose movement even though their brains still send the right signals. Researchers tested whether EEG brain scans could capture those signals and reroute them to spinal stimulators. The system can detect when a ...
Jan. 24, 2026 A large, decades-long study suggests that signs of ADHD in childhood may have consequences that extend well beyond school and behavior. Researchers followed nearly 11,000 people from childhood into midlife and found that those with strong ADHD ...
Jan. 23, 2026 Alzheimer’s may be driven far more by genetics than previously thought, with one gene playing an outsized role. Researchers found that up to nine in ten cases could be linked to the APOE gene — even including a common version once considered ...
Jan. 23, 2026 New research suggests that auditory hallucinations in schizophrenia may come from a brain glitch that confuses inner thoughts for external voices. Normally, the brain predicts the sound of its own inner speech and tones down its response. But in ...
Jan. 22, 2026 A new study reveals that super agers over 80 have a distinct genetic edge. They are much less likely to carry the gene most associated with Alzheimer’s risk, even when compared with other healthy seniors. Researchers also found higher levels of a ...
Jan. 22, 2026 New research suggests that consistent aerobic exercise can help keep your brain biologically younger. Adults who exercised regularly for a year showed brains that appeared nearly a year younger than those who didn’t change their habits. The study ...
Jan. 21, 2026 Scientists have discovered that the human brain understands spoken language in a way that closely resembles how advanced AI language models work. By tracking brain activity as people listened to a long podcast, researchers found that meaning unfolds ...
Jan. 20, 2026 Researchers report that vagus nerve stimulation helped many people with long-standing, treatment-resistant depression feel better—and stay better—for at least two years. Most participants had ...
Jan. 20, 2026 Researchers have identified a key molecular interaction that accelerates Parkinson’s disease by damaging the brain’s energy systems. They designed a new treatment that intercepts this harmful ...
Latest Headlines
updated 12:56 pm ET
Jan. 20, 2026 When you’re short on sleep and your focus suddenly drifts, your brain may be briefly slipping into cleanup mode. Scientists discovered that these attention lapses coincide with waves of fluid ...
Jan. 19, 2026 Scientists at Johns Hopkins have uncovered a surprising new way to influence brain activity by targeting a long-mysterious class of proteins linked to anxiety, schizophrenia, and movement disorders. ...
Jan. 19, 2026 Researchers found that autistic and non-autistic people move their faces differently when expressing emotions like anger, happiness, and sadness. Autistic participants tended to rely on different ...
Jan. 19, 2026 Cannabis-based medicines have been widely promoted as a potential answer for people living with chronic nerve pain—but a major new review finds the evidence just isn’t there yet. After analyzing ...
Jan. 18, 2026 Scientists have discovered that breast cancer can quietly throw the brain’s internal clock off balance—almost immediately after cancer begins. In mice, tumors flattened the natural daily rhythm ...
Jan. 18, 2026 Researchers have identified OTULIN, an immune-regulating enzyme, as a key trigger of tau buildup in the brain. When OTULIN was disabled, tau vanished from neurons and brain cells remained healthy. ...
Jan. 16, 2026 Scientists have discovered that the adolescent brain does more than prune old connections. During the teen years, it actively builds dense new clusters of synapses in specific parts of neurons. These ...
Jan. 15, 2026 Tryptophan does far more than help us sleep—it fuels brain chemistry, energy production, and mood-regulating neurotransmitters. But as the brain ages or develops neurological disease, this delicate ...
Jan. 15, 2026 Spikes in blood sugar after eating may be more dangerous for the brain than previously thought. In a massive genetic study, people with higher post-meal blood sugar had a much greater risk of ...
Jan. 14, 2026 A massive international brain study has revealed that memory decline with age isn’t driven by a single brain region or gene, but by widespread structural changes across the brain that build up over ...