Dr. Richard Gallagher, professor at New York Medical College and Columbia University, believes possession and demons are real. He is the author of Demonic Foes, A Psychiatrist Investigates Demonic Possession in the Modern United States.

We didn't believe in demons or dark energy 30 years ago, partly because we hadn't yet researched and fully understood the subject. Also, we had recently put our college binge drinking days behind us and still had negative energy onboard from that, which can influence your thinking (such as to not believe in demons). Besides, the idea of demons seemed scary, so it was easier to ignore the issue.

Our findings show possession is far more common than most people realize. We don't mean in dramatic ways as portrayed in scary movies. Dark energy is usually much more subtle than that, and why it usually goes unnoticed.

In addition to demons, lost souls--the soul of someone who died but didn't go to "the Light"--can also interfere in similar ways, especially if that soul was possessed when the body died.

Is possession always to blame? Exorcists of the Church claim that many suspected cases of severe possession could be mental illness. However, we've noticed that mental illness can sometimes be caused or made worse by negative entities and lost souls.

Below we describe ways that dark energy and lost souls can mess with you.

"Have another drink, snort, hit, or pill." Drugs and alcohol fuel self-delusion and open your energy field so dark energy and lost souls can come marching in and take over. People are much easier to control when under the influence.

Are those only your thoughts of smoking that cigarette or inhaling that vape? Most addicts and smokers, we've found, have lost souls onboard who attempt to satisfy their habit through the body and mind of their host.

Why did you angrily lash out at that person who didn't deserve it? Did it seem like it wasn't even you doing it? Yes, everyone is responsible for his or her behavior, but demons might also be part of the problem, especially while under the influence.

Sexually promiscuous people can get caught in the trap of looking for sex, again and again, to satisfy a seemingly insatiable urge. Is it only their desire or is there outside influence? Sometimes this hobby takes away from their important goals (some of which demons don't want them to reach). Even worse, it's easy to pick up bad energy through sex, so unless you clear yourself often, you'll accumulate layers of damaging energy and the problem tends to snowball.

Do you ever have thoughts or feelings like you're worthless, stupid, or an otherwise bad person, for no apparent reason? It could be negative energy directed at you. Demons love to make you feel bad because it's easier to zap your energy when you're down and out. They relish keeping you down in any way possible to make you feel the opposite of empowered, light, and energized, which is how you'll feel when you clear yourself of the spiritual garbage.

Why did you have those thoughts that someone is an enemy, even though the person is clearly on your side? Little devils might be targeting you. They love to cause arguments and diminishing love is their game. The best way to counter this is to never assume the worst about a friend or loved one unless you have proof, and always meditate on the situation or problem before taking action or saying something.

Little tricksters love to encourage people around you to think negative things about you, especially when you spiritually protect yourself; the spiritual brats can't get to you, so they'll go through someone else around you. This can make dating and relationships even more difficult for the spiritually inclined, especially with people who drink excessively and, or do drugs. This might also be an explanation for why that neighbor seems to enjoy annoying you.