I think the adjustment to a new country is a difficult one. I also think that your son sounds like he has an anxiety
The main symptom is the almost constant presence of worry or tension, even when there is little or no cause. Worries seem to float from one problem to another, such as family or relationship problems, work issues, money, health, and other problems.
Even when aware that their worries or fears are stronger than needed, a person with GAD still has difficulty controlling them.
Other symptoms include:
Problems falling or staying asleep, and sleep that is often restless and unsatisfying
Restlessness, and often becoming startled very easily
Along with the worries and anxieties, a number of physical symptoms may also be present, including muscle tension (shakiness, headaches) and stomach problems, such as nausea or diarrhea.
Signs and tests
The health care provider will perform a physical and mental health exam. Tests will be done to rule out other conditions and behaviors that cause similar symptoms.
The goal of treatment is to help you function well during day-to-day life. A combination of medicine and cognitive-behavioral therapy (CBT) works best.
Medications are an important part of treatment. Once you start them, do not suddenly stop without talking with your health care provider. Medications that may be used include:
Selective serotonin reuptake inhibitors (SSRIs) are usually the first choice in medications. Serotonin-norepinephrine reuptake inhibitors (SNRIs) are another choice.
Other antidepressants and some antiseizure drugs may be used for severe cases.
Benzodiazepines such as alprazolam (Xanax), clonazepam (Klonopin), and lorazepam (Ativan) may be used if antidepressants don't help enough with symptoms. Long-term dependence on these drugs is a concern.
A medication called buspirone may also be used.
Cognitive-behavioral therapy helps you understand your behaviors and how to gain control of them. Usually someone needs about 10 to 20 visits over a number of weeks. During therapy to will learn how to:
Understand and gain control of your distorted views of life stressors, such as other people's behavior or life events.
Recognize and replace panic-causing thoughts, decreasing the sense of helplessness.
Manage stress and relax when symptoms occur.
Avoid thinking that minor worries will develop into very bad problems.
Avoiding caffeine, illicit drugs, and even some cold medicines may also help reduce symptoms.
A healthy lifestyle that includes exercise, enough rest, and good nutrition can help reduce the impact of anxiety.
A support group allows you to talk to people who share common experiences and problems. This may help ease the stress related to a medical condition.
Support groups are not a substitute for effective treatment, but can be a helpful addition to it.
How well a person does depends on the severity of the condition. GAD may continue and be difficult to treat. However, most patients get better with a combination of medication and behavioral therapy.
Depression and substance abuse may occur with an anxiety disorder.
Calling your health care provider
Call his health care provider if he constantly worry and feels anxious and it interferes with your daily activities.
What you can do is suggest that you son sees a therapist and receives treatment to learn how to cope. I hope that he is open to seeing a therapist. I think pressuring him to socialize does not help but he needs to learn how to reduce his anxiety.
I am glad that he stopped smoking but this will increase his anxiety. Both smoking siggaretes or pot reduces anxiety. I think your son was medicating an anxiety disorder by smoking.
Meditating and self help books will also help him reduce his anxiety.