The term "Attachments" is a now common word for what are actually a dark Spirit or Spirits coming into ones Auric Field and directly influencing the human being on Earth in a negative way. They can instantly trigger a headache or shivers to occur, cause a heaviness and foreboding feeling, along with a low-tonal vibration. They also can affect the emotions of the human being causing them to feel oppressed and then subsequently depressed, as the human being doesn't understand usually right off what is actually happening and thus attributes this sudden and often unexplainable change in emotions and feelings to something they themselves are creating within them. In other words they think that this now downturn in their feelings is caused solely by themselves, not realizing that it is that they are being victimized by a dark Spirit. So when the person thinks that it is their own feelings being upset and depressed, they feel even worse. Education and knowledge as to the source does help initially, which makes for the person to have more control over the situation. Sometimes it becomes like a private inner war, battling to have control over your own thoughts and feelings with someone you barely can see, yet can sense them and their negative words telepathically influencing you, upsetting you, and trying to control you.
It is in essence an attack of attempting to possess the human being, making them feel more and more pushed out of their own physical body, and and even standing offside of themselves if it continues. That is why it is so very important to block these attacks and to be stalwart in your own rights to your own body and not to invite or otherwise draw into yourself these negative Spirits. They might flatter you or tell you something like "you are special" or something to that effect. The ego can be ones own worst enemy in this respect.
Meditation itself is not going to alter this type of attack. Prayer to God our Father to intervene is the only way you can summon the aid you need. We ourselves can try our best to fight these attackers off, yet we get tired and drained from the fight and then when we are at our wits end and exhausted, that is when these negative Spirits can keep at it with having more than one Spirit doing the attacking, taking turns fighting with the human. That is often why there are "attachments" (Plural), which is much like a group or a gang that does these types of attacks.
There is always a reason why these attacks occur, and that is where it is prudent to be aware of this activity and to not be doing anything that could allow for entrance into our Auric Fields those who are of the dark. The Angels will come to aid those who are not willing to be involved with these Spirits, yet I have known the Angels to not aid those who are willing at first to be involved with these dark Spirits and then later change their minds. The Angels will then be using the experience to teach a very harsh lesson to those who voluntarily get involved with these dark Spirits. In that case, the attachments and attack could last for weeks, even months or longer, depending upon the willingness of the human being and the actions of that human being in either the Earth Plane or the Spirit Realm.