Effects of bright light on mood in normal elderly women.

Reduced light appears to be a key factor in seasonal affective disorder (SAD). This study asks whether the reduced levels of light experienced by elderly persons might result in depression and other SAD symptoms, and how normal elderly persons might respond to bright light interventions similar to those used to treat SAD. In interviews with 140 senior citizens, we found virtually no seasonal variation in mood and behavior and very little depressed affect. Seventeen of these seniors who had good mental and physical health, with no major eye problems, participated in a crossover study of the effects of bright light on both positive and negative affect and sleep. Although sleep did not appear to be affected, the bright light intervention tended to make these normal elderly persons feel worse--more irritable, anxious, and agitated. These findings confirm earlier reports that bright light is not beneficial for normal individuals who are unaffected by seasonal changes.

Psychobiological effects of carbohydrate- and protein-rich meals in patients with seasonal affective disorder and normal controls.

Patients with seasonal affective disorder (SAD) frequently report carbohydrate craving and note that carbohydrate ingestion energizes them. Bright artificial light has been shown to reverse the symptoms of SAD, including carbohydrate craving. In this study, 16 depressed SAD patients and 16 matched controls were fed two different isocaloric meals, one rich in protein and one rich in carbohydrates, in a crossover design. Although their biochemical response in terms of plasma large neutral amino acid concentrations was identical, SAD patients reported activation following carbohydrate ingestion, whereas normal controls reported sedation. Marked ordering effects on psychological parameters were noted, suggesting that order should be taken into account as a methodological consideration in meal studies.