Can unexplained smiling occur during recovery from psychosis?

Hello doctor,

My 15-year-old son had a sudden change in his behavior about two and a half months ago. Looking back, there may have been some earlier warning signs. Around five years ago, he used to say he could see people who seemed to be talking among themselves, although they never disturbed him.

At one point, he also believed that someone else was inside him. We are not sure exactly when these thoughts began, but they seemed to come and go and were never as severe or persistent as what we have seen recently.

The first symptom we noticed during this recent episode was that he would smile or laugh without any obvious reason. After that, he gradually became withdrawn, stopped interacting with the family, had poor sleep and appetite, and began experiencing hallucinations and unusual beliefs. He also had one episode of self-harm.

He was evaluated by doctors, and his lumbar puncture, MRI of the brain, and blood tests did not show any significant neurological cause. He was then started on psychiatric treatment. Over the past few weeks, he has improved significantly.

He is now sleeping better (around 12 hours a night), eating well, communicating with us, opening up about his fears, and the belief that someone else was inside him has completely resolved. Overall, I feel he is about 50 % better.

However, one symptom has returned. He has started smiling without any obvious reason again. When I ask him why he is smiling, he calmly says, I just feel like smiling, or The smile just comes out of nowhere.

He is fully aware of it, follows conversations normally, recognizes family members, and answers questions appropriately. He is not smiling because of jokes or anything funny, and he does not appear to be responding to unseen people or voices when this happens.

He is currently taking the following psychiatric medications:

• Serenace 5 two times a day.

• Sizodon LS two times a day.

• Olimelt 10 once a day.

About a week ago, Clonotrol was stopped as per his doctor's advice.

My questions are:

• Is smiling without an obvious reason more likely to be a residual symptom of his psychiatric illness, or could it be an early sign of relapse?

• Could this smiling be a side effect of his medications?

• Is it common for this symptom to persist even though his sleep, appetite, communication, and delusions have improved?

• Would you expect this symptom to improve with continued treatment, or does it usually require a medication adjustment?

• Are there any neurological conditions that should still be considered despite a normal MRI and lumbar puncture?

• Based on his pattern of symptoms and recovery, does this seem more consistent with first-episode psychosis, bipolar disorder with psychotic features, or another psychiatric condition?

I would really appreciate your opinion on whether this smiling is something that commonly improves during recovery and what further evaluation or treatment you would recommend.

Kindly help.