Types of Drugs

Our Types of Drugs section is information provided by Castle Craig Hospital – one of Europe’s leading drug and alcohol rehabilitation centres.

This section of the site has extensive information about different types of drugs:  Effects, signs of abuse, health risks, withdrawal symptoms, detox and treatment.

If you or a loved one is struggling with a drug problem, please contact us. Click the links to find out more about our rehabilitation treatment programme and the admission process. To speak to someone from our admission department, please call (+44) 01721 722 763 or one of the numbers in the purple box on the right. 

Most psychoactive drugs fall into the categories of stimulants, depressants, opiates and hallucinogens. All these types of drugs are addictive, induce dependence and have different effects on the human brain and body.


Stimulants act on the central nervous system and are associated with feelings of extreme well-being, increased mental and motor activity. Examples include cocainecrack cocaineamphetamines (speed) and ecstasy (which is also a hallucinogen).


Depressants are chemicals that slow down the central nervous system and suppress brain activity causing relief from anxiety. The most common depressants are alcohol and cannabis. Others include barbiturates and benzodiazepines (e.g. valiumxanaxtemazepam).

Opiates & Opioids

Opiate and opioid drugs provide pain relief, euphoria, sedation and in increasing doses induce a coma. Examples include heroin, morphine, opium, methadone, dipipanone and pethidine. Click to read about heroin and opiate detox at Castle Craig.


Hallucinogens cause changes in a person’s perception of reality. These include cannabis, LSD, ecstasy and psilocybin (magic mushrooms).

For a detailed description of each drug, click on the titles on the right sidebar ⇨

Castle Craig is one of the most established and respected addiction rehab centres in the UK. Castle Craig provides consulting psychiatrists who diagnose associated mental illnesses like anxiety states, depression, ADD, PTSD, eating disorders, compulsive gambling, and compulsive relationships. For information, call our 24 hour free confidential phone-line: 0808 256 3732. From outside the UK please call: +44 1721 788 006 (normal charges apply).

Page published: August 7, 2019. Page last reviewed and clinically fact-checked January 14, 2022