Mental health conditions


Find out more about some common mental health conditions.


Addiction means not having control over doing, taking or using something, to the point that it may be harmful.
Common addictions include addictions to alcohol or drugs, but it is possible to become addicted to anything, from gambling to chocolate. You cannot control how you use whatever you are addicted to, and you become dependent on it to get through daily life.
Find out more about addictions on NHS Choices.

Alcohol misuse

Many people are able to stick to the recommended levels of alcohol consumption (see box) so that drinking does not pose a threat to their health. However, for some people, the amount of alcohol they drink means that they face a real risk of developing alcohol-related problems. These problems may be:
  • physical - such as heart disease
  • psychological - such as depression
  • social - such as committing domestic abuse or acts of violence
Drinking levels of alcohol that can cause these types of problems is known as alcohol misuse.
Find out more about alcohol misuse on NHS Choices.

Alzheimer's disease

Alzheimer's disease is the most common form of dementia, which is a group of symptoms associated with a decline in mental abilities, such as memory and reasoning. Alzheimer's disease attacks nerves, brain cells and neurotransmitters (chemicals that carry messages to and from the brain).

Although Alzheimer's disease is often associated with increasing age, the exact cause is unknown. Alzheimer's disease is a progressive condition, which means that it will continue to get worse as it develops.

Early symptoms include:
  • minor memory problems
  • difficulty saying the right words
These symptoms change as Alzheimer's disease develops, and it may lead to:
  • confusion
  • personality changes
  • a total change in behaviour

Find out more about Alzheimer's disease on NHS Choices.

Anorexia nervosa

Anorexia nervosa is an eating disorder and a serious mental health condition. People with anorexia have problems with eating. They are very anxious about their weight and keep it as low as possible by strictly controlling and limiting what they eat. Many people with anorexia will also exercise excessively to lose weight.
It is thought that people with anorexia are so concerned about their weight because they:
  • think they are fat or overweight
  • have a strong fear of being fat
  • want to be thin
Even when a person with anorexia becomes extremely underweight, they still feel compelled to lose more weight.
Find out more about anorexia on NHS Choices.


Anxiety is a feeling of unease, such as worry or fear, that can be mild or severe. Everyone experiences feelings of anxiety at some point in their life. For example, you may feel worried and anxious about sitting an exam or having a medical test or job interview.

Feeling anxious is sometimes perfectly normal. However, people with generalised anxiety disorder (GAD) find it hard to control their worries. Their feelings of anxiety are more constant and often affect their daily life.

There are several conditions for which anxiety is the main symptom. Panic disorder, phobias and post-traumatic stress disorder can all cause severe anxiety. These pages are about generalised anxiety disorder (GAD).

Find out more about anxiety on NHS Choices.

Bipolar disorder

Bipolar disorder - previously known as manic depression - is a condition that affects your moods, which can swing from one extreme to another. If you have bipolar disorder you will have periods or 'episodes' of depression and mania.

Find out more about bipolar disorder on NHS Choices.

Borderline personality disorder

Personality disorders are mental health conditions that can cause a range of distressing symptoms and patterns of abnormal behaviour, such as:

  • overwhelming feelings of distress, anxiety, worthlessness or anger
  • difficulty managing such feelings without self-harming, for example by abusing drugs and alcohol or taking overdoses
  • difficulty maintaining stable and close relationships
  • sometimes, periods of loss of contact with reality
  • in rare cases, threats of harm to others


Personality disorders typically start in adolescence and persist into adulthood. The cause is often a combination of genetic reasons and a harmful childhood experience. Personality disorders range from mild to severe.

Find out more about borderline personality disorder on NHS Choices.


Bulimia nervosa is an eating disorder and mental health condition.

People who have bulimia try to control their weight by binge eating and then purging the food from their body by being sick or using laxatives.

As with other eating disorders, bulimia has a number of different causes, including depression, low self-esteem and stress.

Find out more about bulimia on NHS Choices.


Dementia is a syndrome (a group of related symptoms) that is associated with an ongoing decline of the brain and its abilities. These include:
  • memory
  • thinking
  • language
  • understanding
  • judgement

People with dementia may also become apathetic, have problems controlling their emotions or behaving appropriately in social situations. Aspects of their personality may change or they may see or hear things that other people do not, or have false beliefs. Most cases of dementia are caused by damage to the structure of the brain.

People with dementia usually need help from friends or relatives, including help in making decisions.

Find out more about dementia on NHS Choices.


Depression is a serious illness. Health professionals use the words depression, depressive illness or clinical depression to refer to it. It is very different from the common experience of feeling unhappy, miserable or fed up for a short period of time.

When you are depressed, you may have feelings of extreme sadness that can last for a long time. These feelings are severe enough to interfere with your daily life, and can last for weeks or months, rather than days.

With the right treatment and support, most people can make a full recovery from depression. It is important to seek help from your GP if you think you may be depressed.

Find out more about depression on NHS Choices.

Drug misuse

A drug is a chemical substance that acts on the brain and nervous system, changing a person's mood, emotion or state of consciousness. Drugs are often classified by the effect they have.

  • Stimulants, such as cocaine, make people feel full of energy.
  • Depressants (or sedatives), such as heroin, make people feel relaxed.
  • Hallucinogens, such as LSD, make people see, feel or hear things that are not real.
Drug misuse is when a person regularly takes one or more drugs to change their mood, emotion or state of consciousness.
Find out more about drug misuse on NHS Choices.

Eating disorders

Eating disorders are characterised by an abnormal attitude towards food that causes someone to change their eating habits and behaviour.

A person with an eating disorder may focus excessively on their weight and shape, leading them to make unhealthy choices about food with damaging results to their health.

Find out more about eating disorders on NHS Choices.

Gender dysphoria

Gender dysphoria is a condition where a person feels that they are trapped within a body of the wrong sex. The condition is also sometimes known as:

  • gender identity disorder
  • gender incongruence
  • transgenderism
People who have long-lasting and extreme gender dysphoria are known as transsexuals.
Find out more about gender dysphoria on NHS Choices.

Obsessive compulsive disorder

Obsessive compulsive disorder (OCD) is a chronic mental health condition that is usually associated with both obsessive thoughts and compulsive behaviour.

OCD is one of the most common mental health conditions. It is estimated that about 1-3% of adults and 2% of children and teenagers have OCD.

Find out more about obsessive compulsive disorder on NHS Choices.

Panic disorder

Panic disorder is where you have recurring and regular panic attacks, often for no obvious reason.

Everyone experiences feelings of anxiety and panic at certain times during their lifetime. It is a perfectly natural response, particularly when you are in a dangerous or stressful situation. However, for people with panic disorder, feelings of anxiety, stress and panic occur regularly and at any time.

Find out more about panic disorder on NHS Choices.

Personality disorder

Personality disorders are mental health conditions that affect how people manage their feelings and how they relate to other people.

Disturbances of feeling and distorted beliefs about other people can lead to odd behaviour, which can be distressing and which other people may find upsetting.

Find out more about personality disorder on NHS Choices.

Postnatal depression

Postnatal depression (PND) is a type of depression some women experience after they have had a baby. It usually develops in the first four to six weeks after childbirth, although in some cases it may not develop for several months. There is often no reason for the depression.

PND can be lonely, distressing and frightening, but you should be reassured that there are many treatments available. As long as PND is recognised and treated, it is a temporary condition that you can recover from.

Find out more about postnatal depression on NHS Choices.


Psychosis is a condition that affects a person's mind and causes changes to the way that they think, feel and behave. A person who experiences psychosis may be unable to distinguish between reality and their imagination.

Psychosis is not a condition in itself, it is a symptom of other conditions. The most common cause of psychosis is a mental health condition, such as schizophrenia or bipolar disorder (manic depression).

Find out more about psychosis on NHS Choices.


Schizophrenia is a chronic mental health condition that causes a range of different psychological symptoms. These include:
  • hallucinations - hearing or seeing things that do not exist
  • delusions - believing in things that are untrue

Hallucinations and delusions are often referred to as psychotic symptoms or symptoms of psychosis. Psychosis is when somebody is unable to distinguish between reality and their imagination.

The exact cause of schizophrenia is unknown. However, most experts believe that the condition is caused by a combination of genetic and environmental factors.

Find out more about schizophrenia on NHS Choices.

Seasonal affective disorder

Seasonal Affective Disorder (SAD) is a type of depression that has a seasonal pattern. It is characterised by episodes of depression that recur at the same time each year.

SAD is sometimes known as 'winter depression' because the symptoms are more apparent during the winter.

Like any type of depression, SAD can be a difficult condition to live with. Symptoms can make you feel tired, stressed and unhappy. However, a number of treatments and medications are available.

Find out more about seasonal affective disorder on NHS Choices.


Self-harm is when somebody damages or injures their body on purpose. The National Institute for Clinical Excellence (NICE) describes it as 'self-poisoning, or injury, irrespective of the apparent purpose of the act'.

Self-harm is not usually an attempt at committing suicide, but a way of expressing deep emotional feelings, such as low self-esteem. It is also a way to cope with traumatic events, or situations, such as the death of a loved one, or an abusive relationship. Self-harm is not an illness, it is an expression of personal distress.

The physical effects of self-harm can usually be treated with dressings or stitches. The emotional causes may need a psychological (mental health) assessment and counselling (talking therapy) to deal with the underlying issues.

Find out more about Self-harm on NHS Choices.


Stress is the feeling of being under pressure. A little bit of pressure can:
  • increase productivity
  • be motivating
  • improve performance
However, too much pressure or prolonged pressure can lead to stress, which is unhealthy for the mind and body. It can cause symptoms such as:
  • difficulty sleeping
  • sweating
  • lack of appetite
  • difficulty concentrating
Find out more about stress on NHS Choices.