I am so sorry you have to deal with all of this. Welcome to our site - you will find a lot of information, ideas and much much much more support. We are parents who truly understand in ways the people in your off-line life don't/won't/can't. We have been there done that, some of us many times.
At his age you are not doing him favors by letting him come home with-o a job. Once he is back in your home it may be very difficult to get him out again. The items he is stealing clearly all have monetary value and it is not just extremely likely but highly probably that he is stealing from you to purchase drugs and/or alcohol. Many people who are bipolar use alcohol and drugs to self medicate instead of getting more appropriate treatment for their illness. Have you drug tested him at any time?
Searching his room today is very important. As he is not there, be sure to photograph or take video of everything you have found. I seriously and strongly recommend letting him know that he can stay with his father or find another place to live but he cannot return to your home until he is clean and sober, is getting therapy from a counselor for addiction issues and the bipolar, and is under the care of a psychiatrist long enough that his bipolar is stabilized. He most likely needs at least one mood stabilizer, possibly two and an atypical antipsychotic like seroquel or risperdal to help wtih the anger issues and help stabilize the mood cycling.
Is he violent with you when he does not get his way? Verbally, emotionally or physically? If he is, it is even more important to insist he get treatment before he returns. You do him NO favors by letting him stay with you while he is underemployed, not going to school, abusing drugs, your home and your person. This is NOT what you taught him was acceptable and is NOT how you raised him to live. So it may be time to show him that until he is willing to behave in a reasonable, responsible manner he cannot live in your home.
I urge you to find the local alanon and/or narcanon meetings and go to them regularly and often. You will find worlds of help there and a ton of support. While the support on this site is incredible, it is not a substitute for the live support that you can find at meetings. You can look on line (google AA or Alanon and your city and state) or in the phone book under AA or Alanon.
Once he is back in your home, you may not be able to get him to leave without filing formal eviction papers at the courthouse. That can take longer than 30 days - time to get the order, for him to dispute it, and then usually 30 days to leave after the court issues the eviction papers. He will be able to do a LOT to hurt you and destroy your home and finances in that time. If you have the means, you might consider renting a cheap motel room for a week or two and dropping him off there after you pick him up at the airport. Let him know that he can come and get things from your home at a specific time and that you will arrange to have a police officer there while he is getting his things. Or you can tell him you will box or bag up his stuff and he can get it fromt he porch. If returning home is dependent upon getting help then let him know if you are willing to pay for that help or not. He is an adult and since he doesn't seem to be in school he is probably not eligible for helath insurance on your plan. If he is not living with you or getting support from you he may be eligible for health care through the local dept of human services office and/or food stamps and other assistance, as well as help finding full time employment.
Right now he has no real reason to change. He has a nice place to live iwth a LOT of nice things, very few bills, no school or real job responsibilities and all the free time he wants. He is able to live far above his means because you are footing the bill. If he has to EARN his lifestyle he will be far more likely to make real changes and get his life together. He may not do this, or try to live the life he is accustomed to with-o working for it. He likely feels entitled to the cable tv, internet access, game systems, and all expenses paid because that is the life of a child. Now that he is an adult he won't likely realize that he has to pay for these things himself unless you push him out of hte nest.
Others have said you do him no favors by letting him live iwth you and not have to work hard to support himself. They are right. If he has a drug problem or alcohol problem you are either helping him hit bottom and realize that he NEEDS rehab and AA or you are supporting his addiction. Every single penny you spend on an addict goes to support his habit. If you provide a place to live then he doesn't have to pay rent with that money and it can be used for drugs. Ditto food, clothes, and everything else. You wouldn't hand him $400 a month to buy pot, booze or other drugs with, but if you provide a place for him to live then you are doing just that. It is very harsh, but so are addiction.
I realize you probably are not ready to cut him off so completely. It can take a LONG time before a parent can handle that. I understand and so does most everyone here. In that case you need to figure out what you ARE willing to do. Deadbolts on every interior door in the home except his bedroom is a good step. At least put them on your office and bedroom doors so that you have a chance to protect your things. Then lock up every single thing that you value. If he is using there will come a time when he tries to take almsot anything that isn't nailed down or else his friends will. WHen you are home you need to keep your keys and cell phone on your person at all times. Do not ever sleep with your bedroom door unlocked - he will come in and take things while you sleep. I would change the front and back door locks and amke sure every window locks securely also. Then you can insist that while you are at work he must be out of the house. Tell him that you work hard to have a nice life and if he wants one he needs to work at least as many hours as you do. Insist he not be in the home when you are not home.
As he has stolen from you, I would take his game system, tv, and anything else of value that is "his" and pawn them. Give him the pawn tickets and tell him you pawned them to cover the cost of the items that he stole from you. If he wants the items back he can pay the pawn ticket off. If anything else of yours goes "missing" then you need to involve his PO and the police.
As Step said, be prepared for some serious raging and even vandalism/breaking into your home. Those MUST be met with calls to the police or he will continue to do that each time you set limits and try to enforce them. It is HARD to do, but in the long run it is your only chance to save him from a life of drugs and violence.
If you simply are not ready to push him out of the nest, figure out what you are ready and able to enforce. Write it down in a contract. He should be paying monthly or weekly rent to cover living in your home, food, utilities, etc..., specify what bills he needs to pay such as his cell phone, internet usage, cable tv channels if he "must" have HBO or other things that you don't use, etc... Put in writing what the rules and conditions for living in your home are (I would include not using drugs or alcohol, reasonable time for him to be home each night, not damaging your property/possessions, not taking things that are not explicitly his, when/if he can have friends over, and any other rules for living with you.). Also write down what the penalty for violating the rules is. Again, I would make not paying rent on time, not paying his other bills, bringing drugs/alcohol onto your property, using drugs/alcohol, coming home drunk/high, stealing anything from you, damaging your property, not keeping his room clean to whatever standard you set, etc.... conditions that you can and will insist he leave the home for. You might let the room clean condition slide unless he is so bad about it that the room stinks or attracts pests, etc....
The bills required should be fairly close to what he would earn from a full time job. maybe give him 2 weeks grace time to get the job. I would NOT EVER let him drive your vehicles. Don't repair his ruined vehicle either. In fact, if it is in his name you may want to insist that he either get it repaired or remove it from your property (if it is still on your property). Many communities consider cars that do not run to be eyesores and can fine you for them. It depends on the area where you live, but is something you should check out. IF he needs transportation he can call a friend, walk, take a bus or even ride a bicycle. Don't provide rides unless you are already going there or it is to a doctor/therapist.
I know this is incredibly hard for you. It truly hoovers to have to tell your child these things and to have your child treat you so badly. Whatever you decide, make sure that you ONLY tell him things that you will 1000% follow through on. It is far worse to set out a lot of rules and not enforce them than it is to set very few rules that you will enforce no matter what. You can always add more rules as you are ready/strong enough to enforce them.
The exception is violence. If he is violent against you it is NOT somethig you can let slide. Otherwise he will not stop the violence toward you and likely it will spread Occupational Therapist (OT) many others in his life, esp women. If you set absolutely no other rules, set the rule that for violence you will call the cops and his PO and press charges. One nasty consequence of NOT doing this is that eventually he will take it to people other than family and then he may end up in serious legal trouble or even in prison. If he has been or is violent to you (including punching walls, etc...), PLEASE go to a domestic violence center (not the shelter, they usually have an office where they do individual and group therapy and provide other services/resources. Many of us don't think of this when it is our child hurting us. We feel we somehow caused it and if we had been somehow better parents our child would not be violent toward us, our belonging and our home. It simply isn't true and the help and support at a DV center is incredible.
Above all, stick around here. It is another source of incredible support and love and there isn't much we need more as we navigate life with a difficult child than that.
