PARSIPPANY — The back-to-school season is upon us, time for kids to complete those summer assignments and parents to find that long checklist of school supplies. While lots of kids will enjoy starting a new grade, others will experience anxiety. First-day jitters are common, but parents and other caregivers need to pay attention to ensure that what their child is experiencing isn’t something more serious.

“It is so important for parents and others who interact regularly with children, especially teenagers, to be aware of signs of mental illness or substance abuse,” said Mary Vineis, NewBridge Services director of Community Response and Education. “The second part of the equation, of course, is knowing how to reach out and offer help.”

The National Council for Behavioral Health, which administers Mental Health First Aid in the U.S., provides five signs to look out for that indicate a teenager is in distress:

1. They stop showing interest in activities they enjoyed, and don’t adopt new interests and hobbies.
2. Their academic performance slips, especially in a subject they enjoyed.
3. They don’t want to talk about their future.
4. They withdraw from friends, family and social activity and become socially isolated.
5. They suddenly eat a lot more or a lot less than they had been eating, or they completely avoid eating meals in front of others.

NewBridge Services offers Youth Mental Health First Aid training to teach adults who interact with kids ages 12 to 18 signs and symptoms of mental illness and addiction and how to reach help children.

Mental illness affects an estimated one in five adolescents, yet less than half of preteens and teens with disorders get treatment, Vineis said. Recognizing the difference between normal growing-up behaviors and mental disorders is crucial. Half of all chronic mental illness begins by age 14 and 75 percent by age 24.

The eight-hour, evidence-based training teaches a five-step action plan. Anxiety, depression, substance use, disorders in which psychosis may occur, disruptive behavior disorders (including ADHD), and eating disorders are among the topics covered.

For lots of kids, the back-to-school jitters are just that and those feelings of unease will go away within a few weeks. Johns Hopkins Medicine offers these tips to ease the jitters in the week or two before school starts:

• Begin back-to-school routines at home, getting to bed and waking earlier.
• Get your child together with a classmate or two so they reconnect.
• Rehearse school drop-off, and let your child play on the school playground. Go into their new classroom if that’s allowed.
• Let your child know it’s normal to be a little nervous starting the new year, and reassure them that they will adjust quickly and enjoy the new experience.

Even young adults need help transitioning, especially if they’re about to live away from home at college for the first time. Before moving day, NewBridge Services Chief Operating Officer Michelle Borden recommends parents have a heart-to-heart with their teen about ways they can stay healthy and avoid common pitfalls of newfound independence.

“You may want to lay down the law, but do it in a way that’s more of an adult conversation so they know what your expectations are,’’ said Borden, a licensed clinical social worker. Topics could include nutrition, sleep, and alcohol and drug use, keeping up with assignments and grades, and managing extracurricular activities. For teens who have struggled with stress during high school, Borden suggests parents urge them to investigate on-campus mental health resources.

Parents and teens should also talk about how to keep in touch, now that they won’t see each other daily. “Find a new normal for communicating,’’ Borden said.

Texting is a good option, she said. It’s fine to send a text ever few days “saying you want to hear how things are going. Ask about what activities they’re getting involved in and what their classes are like,’’ Borden recommended. “Stay away from saying things like, ‘we really miss you here.’ Let your child guide the discussion about whether they are homesick or not.”

Sending care packages is another way to show your love. “Just be sure to text your child to check the mail!’’ she said, noting teens aren’t always attuned to checking snail mail.

The winter break will be a key time for parents and their child to discuss how the first semester went, and how to address any problems. “If your teen is failing classes, you can’t ignore that. Talk openly about the consequences of not meeting classroom expectations as they relate to tuition, costs of repeating classes, and the impact on any scholarships.”

Hopefully, parents won’t have to have that conversation. For now, parents should focus on steeling themselves for drop-off day.

“It’s scary for parents to back off and let go,’’ Borden said.  “Leave your child with words of love and encouragement, not reproaches about keeping their room clean. Say,  ‘we love you, we’re proud of you, we are here for you, and now, you are off on your newest adventure!’ Then, don’t look back. Look forward!”