Final answer:
Alexis has Seasonal Affective Disorder (SAD), a type of depression with a seasonal pattern option (c) occurring in winter and possibly linked to melatonin production. Light therapy is a non-drug treatment that can help regulate melatonin and reduce symptoms.
Step-by-step explanation:
Alexis experiences the symptoms of major depressive disorder, but only during midwinter. The kind of depression Alexis has is a seasonal pattern, commonly known as Seasonal Affective Disorder (SAD). SAD is a mood disorder that often occurs in the winter months in response to the shorter days and reduced sunlight.
Symptoms, which can include increased appetite, sluggishness, and increased sleepiness, are thought to be influenced by the hormone melatonin, which is produced in the brain in response to darkness and can affect sleep patterns and mood.
Non-drug therapies for SAD include light therapy, where exposure to bright light can help regulate melatonin production and alleviate depressive symptoms.