Not an expert but I would suggest teen depression can be due to low self esteem due to having acne. Basically the opposite of your question. Chances of teen depression probably increase if a teen has acne.
While there is a mind-body connection to nearly all things in life, I do not think acne alone which is a demonstrated result of the increase of hormones and body changes of puberty, can be caused by depression alone. Just as I would never suggest someone gets cancer entirely because of a mental or emotional state they are in, there is no doubt that continually being in a depressed emotional, clinically negative mental, or high anxiety/stress situations will result in a weakening of the immune system, which could let any disease manifest easier.
To ask if acne is a symptom of teen depression, as Cascade has pointed out, is not looking at the whole situation. While acne can increase the likelihood of depression, depression can also increase the likelihood of acne. As Rita mentioned, depression can lead to poor life choices (diet, hygiene, and more), while levels of stress also have significant impacts on inflammation. James Green points out in his book Male Herbal a course of action for acne: "Diet, of course, is a contributing factor, but it is seldom the only one. This condition is treated internally as well as externally." He then goes on to explain how much it can help to use something to move the lymph (a lymphatic), liver support (a hepatic), a diuretic and an antimicrobial. Taken these suggestions, I would offer the use of Cleavers or Calendula (Easy to grow both) as lymphatics, dandelion leaves as a diuretic and hepatic as well as burdock root or yellow dock. Make all of these into a salad, put the roots in a nice tea (decoct, boil, for about 10 minutes), and top with some fresh garlic as an anti-microbial. Mix with some other good leafy greens, and a delicious salad dressing (Tahini, Lemon juice and Olive Oil?) and eat regularly. This combined with a nice hygeine regimen will clear things up nicely. One thing that made a huge difference for me growing up with acne was when I realized that allowing healthy moisture on my face was a good thing. The skin wants to be supple and healthy, and if we don't scrub it with harsh cleansers (sodium laureth sulfate was invented by the army as a tank degreaser!) and we let the natural oils accumulate while gently washing sweat and dirt off at least daily, with a good rinse and light ph-balanced soap, then things will develop nicely.
Another thing to note is that acutane, a commonly prescribed drug, has extreme effects on the mood states of many. So, be careful if depression is already an issue.
So yes, acne can help bring about depression and depression (stress, etc) can help bring out inflammation and pimples on the skin. To say that acne is a symptom of depression is misleading and only a tiny part of the whole true story.
Have a great day!
I also think that depression may effect a teen's diet and just general will to take care of themselves. I think it may be interesting if its diet choices like sugary treats or junk food, which can offer a temporary boost to mood, is also linked to development of acne.
I think this infographic will greatly complement your article.
This discusses how modern parenting could contribute to teen violence. Enjoy!