Children no matter what age can develop most of similar emotional problems to adults. The most common ones are anxiety and depression. 
In this article we only discuss about anxiety disorders in children. Anxiety is a large category of emotional problems in human being. It can manifest itself as fear, nail biting, sleep problems, Children separation anxiety from care givers, social anxiety, OCD, bed wetting, etc. Problems such as bed wetting are more common in younger children mostly in reaction to anxiety. Of course urological problem such as bladder problem should be ruled out as well. 
OCD itself could manifest as a forms of obsession or compulsion or both. Obsession is about a thought which is constantly on persons mind and cannot stop. This can affect negatively on person’s life quality and feeling etc. Compulsion is repeating same behavior such as washing hands repeatedly but still don’t think is clean, close or lock the door many times but still think not closed, another words checking and rechecking again and again to the point of fatigue but can’t stop. Other forms of OCD is sometimes manifest as hair pulling, skin-picking and more. 
Most category of anxiety mentioned above in children and later as adult is developed during the early age of child physical and psychological development. The following things happened  in early part of child’s life can lead him to many kinds of psychological disorders included in the anxiety category. They include, parental marital discord, each parents emotional difficulties such as anxiety, depression, etc., care givers psychological issues, trauma, physical or psychological abuse, hunger, poor or ineffective parenting, parental over protection, parental neglect, being bullied at school and many more. Of course there is another kind of anxiety which can develop after sudden loss, trauma, accident or disaster which is called PTSD. 
Children or adult with PTSD often repeatedly experience the trauma or disaster situation, don’t feel safe, depressed, prefer stay alone, have nightmares, sometimes feel psychologically numb, don’t feel safe about his surrounding and even sometimes can lead to suicide.

The above was a very brief of description of this major psychologically problem which many children as well as adult suffers and don’t see end to that. 
Actually taking medicine for these problems does not address the root of this problem but allow the problem sticks to child for rest of their lives without an effective emotional closure. If such problems are not treated by psychotherapy by clinical psychologist the problem with get worse as child grows up and will cause problems with his learning, attention, concentration, memory, happiness, health, constant suffering etc. Medicine can only mask the problem, make the person psychologically numb and also cannot be taken for long period due to many side effects on child’s different organs including kidney, liver, stomach, immunes system, etc.
Such children should be first evaluated by clinical psychologist performing different forms of psychological testing (paper and pencil kind of test) including personality testing to understand the root of problems. Such tests are actually is a kind of psychological CT or x-ray which is important for psychological treatment to be more effective. Then psychologist proceeds with psychotherapy of child and sometimes also the family with child present. Such treatment aims to heal the years of neglect, trauma, poor or ineffective parenting, etc. and allow the child to be free from these factors which lead him to become anxious, depressed at the first place.
Tips for effective parenting reducing child to develop such disorders:
1-	Make the child feel safe. You can help by working on your own psychological problems if have, improve your marital relationship. 
2-	Provide a harmonious, happy family with consistent reward to child no matter positive or negative and on timely basis
3-	Support the child gently in his understanding the world and people around him and build trust in self and others
4-	Don’t over protect or neglect the child
5-	Allow child to taste life’s up and down, but be with him by giving him emotionally support as he explores these phenomena
6-	Avoid physical punishment or ridicule or calling him names especially when it comes to his physical or mental deficits.
7-	Don’t lie to your child or try to keep secrets the family’s misfortune. Children need to be involved with family affairs and grow as part of family not an outsider
8-	Don’t use and pressure your child to achieve what you could not achieve
9-	Don’t’ force child for extra activities after school such as playing certain instrument if child not really interested. You can gently help to choose certain extra activities but not force or punish for that. 
10-	Allow child to be a child. They also need daily time to play and enjoy this period of their childhood.
11-	Encourage child for social activities and making friends.
12-	Have certain rules and chores at home for child to follow. These rules should not be harsh.  Such mode will help build responsibilities in child.
13-	Finally try best not to ask other family members do your task of parenting

Take a good care of your child psychological development. As parents you have this power and choice, so act responsibly for his healthy emotional growth. 
Good luck
Dr.Mike