Final answer:
Dr. Griffiths diagnosed Manuel with major depressive disorder because he appears tearful to others and spends weeks at a time feeling sad, empty, and hopeless.
Step-by-step explanation:
Dr. Griffiths diagnosed Manuel with major depressive disorder because he appears tearful to others and spends weeks at a time feeling sad, empty, and hopeless. Major depressive disorder is characterized by feelings of intense sadness and despair, along with other symptoms such as decreased enjoyment in activities, changes in appetite and sleep patterns, difficulty concentrating, and feelings of worthlessness. Physical changes, such as weight loss and disruption of hormonal circadian rhythms, can also occur. Treatment options for major depressive disorder include psychotherapy, electroconvulsive therapy, deep-brain stimulation, and prescription medications.