Dear Mariella

I am a 16-year-old girl and I have been seeing someone for more than a year. He's 18. Our relationship was never normal - he struggled with drugs and a commitment phobia. Three weeks ago he told me he needed £100 for his dealer or he would be killed. I couldn't get the full amount at such short notice so I gave him £50 and he said he was very embarrassed and sorry and that I would have the money within a week. A week later I got a phone call from him saying that he had the money and he could give it to me the next day. Since then he seems to have disappeared. I have been calling nonstop and he doesn't pick up the phone. I am actually getting worried now, as he may be in some kind of real trouble. He has never ignored me or lied to me before. What do I do?

If you are being honest with yourself, which is as important as expecting it from him, you know there is no way that your money has gone on saving his skin. We can spend hours sifting though the truths, the half-truths and the downright lies you've been told, but ultimately this is not a person you can rely on, or hope for any kind of future with. The only thing this man is in thrall to is narcotics. There's no room in his life for a real live person while he's conjuring up his highs chemically. You really need to understand that. It's not personal; it's actually got nothing to do with you. This man is good for nobody and nothing until he has stopped being a junkie. And just in case you think that's too strong a word to describe his problem, let me assure you that anyone borrowing money off their 16-year-old girlfriend to fund a supposedly recreational habit is not a casual user.

I once shared a flat with a girl who turned out to be a junkie. I tried to maintain our friendship through thick and thin, the fag burns on the furniture, the dodgy visitors at all times of day and night, and the sight of my clever, articulate girlfriend slurring and drooling in the sitting room. One day while I was out, she had me robbed of every piece of jewellery and sentimentally precious item I possessed just to fund a couple of days' drugs. You could say she failed to appreciate my commitment to our relationship! The next day I packed what was left of my belongings and left her behind.

I appreciate it's harder for you: your hormones are telling you you're in love, and who knows, you just might be - but with an illusion. As long as he continues to abuse drugs, he's just a vessel for his habit. In the place of the man you think you care for is an alien being that is entirely dictated to by his addiction.

When drugs become a lifestyle, you are faced with two options: join in or run as fast as you can in the opposite direction. Thankfully, you don't sound like you're itching to become part of his crowd, so prepare to take the latter option. Please don't waste time thinking he needs you or that you can change him. Neither is true, but you could waste an awful lot of your precious life trying. I beg you not to. I'm not some middle-aged fuddy duddy - or maybe I am. Anyway, I've been as close as anyone should ever get to the drug scene. Close enough to know that the only winners were those who had the good sense to get out while it was still fun. There's no fun to be had in borrowing money and lying to the people you care about; it will only increase your cynicism toward those around you. In many respects there's only one thing sadder than a tragic junkie, and that's the misguided person propping them up while thinking they're making a positive contribution.

Tell your boyfriend that until he's repaid your £50 and sought help for his habit, you don't want to hear from him. Then get a new phone number. If he manages to kick it, he'll have the energy and necessary incentive to find you. If he doesn't, then he'll only be in contact if you're making life easier for him, which means harder for yourself. His situation is not your fault, it's not your problem, and you certainly can't save him. If you are really interested in my advice, here it is. Change your number, tell your parents or an adult you trust the truth about him and the money he's borrowed, and if he doesn't understand 'goodbye', tell the police.