Log on to any online forum for parents of teenagers and you’re likely to find a query or two resembling this one, posted on the Berkeley Parents Network:

My seventh grader just hit puberty and all of a sudden she’s so sad! She was never like this before, and I don't remember being like this. She cries and cries, alone in her room. We’ve always been very close, and now she just wants to be alone in her room. She has always been exceedingly sweet and honest and caring, and overnight she is moody, crying, sad, and very frustrated. Is this simply puberty? Will it mellow out?

If moodiness or withdrawal is "normal" for teens, how can you spot a real problem, such as depression or anxiety? And how do you know when it’s time to consult with a professional?

Parents often think they need to do serious detective work to figure out whether their kids are okay. But it may not be as tricky as you think.

The answer may come from just knowing your teen. More than almost anyone else, you’ll be able to tell whether her behavior is truly out of character. In other words, is she just moodier than usual, or does she seem like a whole different person?

Related: Is Your Teen Being Cyberbullied?

Start by paying attention to the most obvious signs. David Franklin, MFT, a therapist in Lafayette, California, who specializes in adolescent issues, says that more often than not, when a teen is having trouble coping it will show up as one or more of these three common symptoms:

  • Changes in sleeping patterns (difficulty sleeping, or sleeping more than usual)
  • Changes in appetite or eating habits (eating less or eating more than usual)
  • Inability to concentrate (on schoolwork, driving or other activities that require focus)

Related: How To Help Your Teen Get Enough Sleep

Less obvious symptoms that could signal depression or another serious condition include:

  • Loss of interest in normal activities
  • Irritability, frustration, agitation or anger
  • Crying spells for no apparent reason
  • Unexplained headaches, stomachaches or other body aches
  • Abuse of alcohol of drugs
  • Self-destructive thoughts
  • Self-harming behaviors, such as cutting or burning
  • Lack of concern about appearance

Related: Parents, Beware: Come Summer, Teen Driving Is Risky Business

“Are you okay?”

Intuitive parents will naturally pick up on even subtler cues, like changes in energy, posture or eye contact. But there’s another solution, says Franklin: Just ask.

“Parents have the ability to say, ‘I’ve noticed you’re not your usual self lately — are you okay?’ or to ask, ‘What do you need?’ I believe that teenagers generally have a lot of wisdom and an interest in their own wellbeing. Often they will answer questions if they know they’re being asked with genuine concern and there’s no hidden agenda.”

What’s most important, Franklin says, is not so much what they’re going through as how they’re experiencing it. “Are they moving through it, or are they getting stuck? And ultimately, how are they dealing with their ‘stuckness’?”

“I generally don’t get worried about kids simply because they’re quiet, or different from their peers, or because they only have one friend, or they’re happy to lie in bed all day with a book,” Franklin says. “Those qualities don’t necessarily concern me. What may concern me is ‘Do they feel overwhelmed?’ ‘Do they feel helpless?’ And if so, how are they handling these challenges? Are they handling them in a constructive way or in a destructive way?”

How to find a therapist

If you’re still wondering whether your teen has a serious problem or is “just being a teenager,” consulting with a therapist experienced in working with teens may help.

If possible, speak with several therapists and choose the one whose style feels like the best fit for your child. Research shows that the quality of the relationship with the therapist predicts success better than any other factor, including methods or length of treatment.

To start your search, ask for recommendations from friends, school counselors or healthcare providers. If privacy is an issue, post a message to a local online forum, where you can ask anonymously.

Related: Beyond Facebook: Apps Your Teen Is Using Now And What To Do About Them

Susan LaCroix is a writer, editor and psychotherapist living in Berkeley, California.

The opinions expressed in blogs and reader comments are those of the writers and do not reflect the opinions of SafeBee.com. While we have reviewed the content to ensure it complies with our Terms and Conditions, SafeBee is not responsible for the accuracy of any of the information.