Substance abuse is always a mental illness

Brain damage from drug use


Alcohol is a cell poison, which is why it is also used as a disinfectant. Pure ethyl alcohol, i.e. drinking alcohol, is therefore only drinkable in small quantities. A heavy high kills brain cells and can be fatal. Regular consumption of small amounts can also cause extensive brain damage. One of the most serious diseases is the so-called Korsakoff syndrome, in which entire regions of the brain die off: those affected cannot remember anything, are severely demented (intellectual decline) and disoriented. But this is only the final stage. With regular consumption of quantities that are no longer low-risk, the mental decline is creeping. A blackout after a long night, for example, should be interpreted as a warning sign.


Ecstasy affects the concentration of serotonin, an important messenger substance in the brain. In the most recent research there is increasing evidence that this can lead to serious brain damage. These are very likely dose-dependent: the more consumed, the greater the damage. The damage is noticeable primarily as memory problems. For example, one study found that ecstasy users forget more than drug-free people when they should go shopping.

According to a recent animal study, ecstasy also damages the blood-brain barrier. This is the brain's protective wall, which normally prevents harmful substances and pathogens from entering the brain. How permanent the brain damage caused by ecstasy use is is not yet known. In humans, the authors of the study speculate, the damage to the blood-brain barrier could persist for years after the last ecstasy pill.


The consumption of cannabis, especially regular and long-term use, has negative effects on brain performance. Impairments of the short-term memory were determined and losses in logical thinking and judgment were demonstrated. According to previous knowledge, there does not seem to be any permanent brain damage, as the brain recovers after the consumption has ended. However, the learning of new information seems to be permanently impaired.

Amphetamine, methamphetamine

Neurotoxic effects (damage to nerve cells) have been well demonstrated with amphetamines. The most toxic is methamphetamine, also known as crystal. Difficulty concentrating and attention deficits are the more harmless consequences. Cerebral haemorrhages and strokes with sudden paralysis are more serious. The consequences of long-term amphetamine use can also be seen in behavior. Those affected often tend to repeat the same activities over and over again, for example repeatedly opening a drawer and fixing themselves on a certain thought.


Pinel JPJ (2001). Biopsychology. Heidelberg: Spectrum Academic Publishing House.
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