What are the overall health effects of cannabis?

Cannabis can affect health on several levels. The consequences concern the young brain, memory, mental health and the risk of dependence. Which consequences occur for you depends on quantity, frequency, age and personal history.

This overview summarises what the prevention agency BIÖG and the specialist website drugcom describe.

The most important consequences at a glance

Four areas are at the forefront. They are connected but can be considered separately:

• development of the young brain, which can be influenced by use
• memory and learning, with possible consequences for school and vocational qualifications
• mental health, with psychoses occurring more frequently among people who use cannabis
• dependence, which can develop psychologically with long-term use

Brain and development

BIÖG describes that the young brain is in an important phase of development. Cannabis can influence this development. BIÖG writes that young people are far more at risk from cannabis than adults.

The article Until what age is the brain developing? looks at the question of age and explains how it can be put into context.

Memory and school qualifications

BIÖG names a concrete danger: memory can deteriorate, so school or vocational qualifications may be at risk. Drugcom adds that an early start can have lasting impairments on cognitive performance. For learners, this is one of the most important warnings of all.

How this shows up in everyday life and what you can check is explained in the article How does cannabis affect memory and school qualifications?.

Psyche and psychosis

According to BIÖG, psychoses occur more frequently in people who use cannabis than in people who do not. This overview does not give the frequency more precisely. As an example of delusions, BIÖG names feeling persecuted even though nobody is after you.

For acute complaints of this kind, a medical assessment is important. You can read more about the warning signs in the article Which warning signs point to a psychosis?.

Dependence

According to BIÖG, around one in eight people who use cannabis develops a dependence. Drugcom describes that psychological dependence can develop with long-term use. This means that use continues again and again despite the wish to stop, and important areas of life are pushed aside.

How you can recognise an emerging dependence is described in the article How do you recognise cannabis dependence?. The questions there help with self-assessment.

Respiratory tract, heart, pregnancy and other effects

In addition to the four areas, the specialist agencies describe further findings.

• Respiratory tract: according to drugcom, there is still no clear evidence that smoking cannabis increases respiratory diseases. Cannabis smoke contains roughly the same amount of tar as tobacco smoke, and if cannabis is mixed with tobacco, the risks of tobacco smoking apply.
• Heart and circulation: previous studies suggest an increased risk of heart attack in the first hour after use, because cannabis can raise the heart rate. Drugcom emphasises that further studies are needed.
• Pregnancy: the Deutsche Hauptstelle für Suchtfragen advises against cannabis use when planning a pregnancy, during pregnancy and while breastfeeding.
• Motivation: according to Sucht Schweiz, a persistent amotivational syndrome is not considered confirmed, although cannabis can dampen motivation during intoxication.

The state of research is unclear in some of these areas.

If you have complaints, a medical assessment is the right approach.

Early start and course of use

According to drugcom, an early start is particularly problematic because it can have lasting impairments on cognitive performance. The course also matters, because a long course of use increases the risk of consequences. More on this is explained in the article What are the consequences of starting cannabis use early?.

How quantity and duration change the picture

According to BIÖG, it becomes more dangerous to health the longer and more often you use cannabis, and the younger you are. Anyone who takes a single puff from a joint does not become dependent immediately, according to BIÖG.

Drugcom describes psychological dependence as a consequence of long-term use. Anyone who continues use for months although it causes problems should therefore not wait until the next crisis.

Who is at greater risk

Not every person who uses cannabis develops problems. Drugcom describes that the risk of becoming dependent is not the same for everyone: psychosocial risk factors and mental health problems such as depression or anxiety symptoms increase it.

More on this is explained in the article “Which protective factors exist against risky use?”.

Mixed use as an additional factor

According to cannabispraevention.de, cannabis and alcohol together put a strong strain on the circulation and often lead to nausea and vomiting. Feel-ok.ch writes that the effects of the individual drugs can reinforce each other. In the case of mixed use of alcohol and cannabis, taking part in road traffic is completely forbidden according to drugcom. The details are in the article What happens when cannabis and alcohol are consumed together?.

What you can do with this information

The consequences do not predict what happens to every person. They show risks that become more likely with certain patterns. Anyone who knows them can react earlier, and this is precisely the benefit of education.

• Pay attention to changes in memory, concentration and school performance.
• Observe mood, sleep and withdrawal from friendships.
• Count how often you use, and compare the number over several weeks.

If two or more of these points apply to you, a conversation with a counselling service or a doctor is worthwhile.

Why an overview alone is not enough

An overview like this does not replace personal advice. The consequences affect each person differently, and circumstances of life, pre-existing conditions and the form of use change the picture. Anyone who is unsure should therefore speak with a doctor or an addiction counselling service. Building on figures alone would be a mistake.

Health is more than a single value. Anyone who keeps an eye on sleep, exercise, nutrition and social contacts additionally protects themselves.

Keeping health in view

Regular self-checks help to notice changes early. A note on mood, sleep and performance can help you notice changes. If you notice conspicuous changes, a doctor is the right point of contact.

A question to ask yourself

Ask yourself what the use currently brings you and what it costs you. The honest answer shows where a change could make sense.

Where to get help

If you are worried about your health or that of someone in your environment, an addiction counselling service is a good first point of contact. The Suchthilfeverzeichnis (addiction help directory) of the Deutsche Hauptstelle für Suchtfragen shows services near you. For physical or mental complaints, a doctor comes first.