Mary experiences long periods of time when she feels very depressed. however, she occasionally goes through phases where she is highly focused on her painting and she creates beautiful works that provide a rewarding experience to her. it is most likely that mary would be diagnosed with

The correct answer is bipolar disorder.

Bipolar disorder, also called manic depression, is a mental health condition that causes extreme mood swings and behavioral changes.

The disorder is characterized by two phases: the emotional heights (mania) and the emotional laws (depression).

During the emotional heights, a person has increased energy, is optimistic and very active. The person has an exaggerated sense of self-confidence and  experiences extreme well being.

During the depressive stage, a person lacks energy and inspiration, has trouble concentrating and it's prone to negative thoughts and actions.  

the telephone is the answer