Hi rusty timberjack,
I work at a mental health center and we treat lots of adolescents. When the child presents with depression, weight gain/or trouble losing the weight, he orders a TSH test. He tried to get a well rounded diagnosis.

I think it's appropriate to ask for the test.

My 17 year old daughter was diagnosed with hypothyroidism. She was immediately put on SYNTHROID. She had been lethargic, weight gain was substantial, and had the dry skin with rashes as well. As long as she was on medication she was able to exercise and have a normal life. She chose to go off her meds a year later (saying she didn't want to be chemical dependant, alas) and started to gain back the weight. She broke her ankle at work and was 'off her feet' for several months. Now, she is morbidly obese and has finally come to her senses about the weight and the necessity of medication.