Substance use disorders generally include overuse, abuse, and addiction to a mood-altering substance such as drugs and alcohol. As with any addiction concern, the first step is to assess or determine what level of problem, if any, exists. Getting professional assistance with assessing the problem can be highly beneficial. For general information about addictions please see the Addictions page.

Many chemical addictions start with social, casual, or prescription use. Over time, however, the frequency and amount of use increases to an inappropriate amount and it begins to become a habit. The kind of substance and the frequency of use required to develop an addiction will vary from person to person. Family history can have an impact on whether or not an addiction develops.

Although alcohol is also a chemical, I have devoted a separate page to Alcohol abuse and addiction. Here I will discuss a little about illicit and prescription drugs. There are many misconceptions about drugs and the dangers they present to users. Here’s a list of the primary categories of commonly used drugs and signs of overuse:


  • Heightened sense of visual, auditory, and taste perception
  • Increased appetite
  • Poor memory and difficulty concentrating
  • Increased blood pressure and heart rate
  • Red eyes
  • Decreased coordination
  • Decreased motivation
  • Slowed reaction time
  • Increased anxiety when not using
  • Paranoid thinking or being on-edge

Some marijuana can cause hallucinations and delusions depending on its strength. There is great variation in the strength of marijuana. It also can cause cancer.

Barbiturates and benzodiazepines (include tranquilizers and many prescription drugs)

  • Memory problems
  • Confusion
  • Drowsiness
  • Slurred speech
  • Lack of coordination
  • Slowed breathing and decreased blood pressure
  • Dizziness
  • Depression, moodiness, or irritability

Methamphetamines (include cocaine, amphetamines, methamphetamine, and methylphenidate)

  • Euphoria
  • Restlessness
  • Weight loss
  • Paranoia
  • Decreased appetite
  • Rapid speech
  • Irritability or easily agitated
  • Depression as the drug wears off
  • Nasal congestion and sniffling in users of snort drugs
  • Insomnia
  • Increased heart rate, blood pressure, and temperature

Street or club drugs (include GHB, Ecstasy (MDMA), Rohypnol (“roofies”) and ketamine)

  • Euphoria
  • Reduced inhibitions
  • Heightened or altered sense of sight, sound and taste
  • Decreased coordination
  • Poor judgment
  • Memory problems or loss of memory
  • Decreased or increased heart rate and blood pressure
  • Drowsiness and loss of consciousness

The use and abuse of these substances can have life-threatening consequences from any level of use. If you or someone you know uses drugs, consider seeking help immediately.