Mood disorders (such as depression or bipolar disorder)
Anxiety disorders
Personality disorders
Psychotic disorders (such as schizophrenia)
Eating disorders
Trauma-related disorders (such as post-traumatic stress disorder)
Substance abuse disorders

1. Anxiety disorders

Anxiety disorders cause people to respond to certain objects or situations with fear or dread. Common anxiety disorders include:

• Generalized anxiety disorder
• Panic disorder
• Social anxiety disorder
• Specific phobias

Symptoms of anxiety disorders:

Tiredness
Muscle tension
Stomachache
Chest tightness or pain (see a doctor if this occurs—chest pain may be a sign of a medical emergency)
Fear of being embarrassed
Blushing
Sweating
Trembling
Shortness of breath
Rapid heartbeat
Headache
Dizziness

Causes of anxiety disorders:

Genetics
Stress
Environment
Chemical imbalances in the brain

Risk factors for anxiety disorders:

Traumatic events in early childhood or adulthood
Physical health conditions such as thyroid problems or arrhythmia
Family history of anxiety or other mental disorders

2. Mood disorders

Mood disorders are also known as affective disorders, and they involve persistent grief or sorrow alone or combined with periods of ecstasy or happiness. People with mood disorders may experience fluctuations between extreme joy and extreme sadness. Some of the most common mood disorders include:

Bipolar disorder
Depression
Cyclothymic disorder

Symptoms of mood disorders:

Feelings of hopelessness or helplessness
Difficulty sleeping or daytime sleepiness
Loss of appetite or binge eating
Poor concentration
Fatigue or low energy
Low self-esteem
Trouble making decisions
Feeling ecstatic, high, or elated for no reason
Feeling jumpy or wired and being more active than usual
Being short-tempered or seeming extremely irritable
Racing thoughts and talking very fast
Needing less sleep
Feelings of being unusually important, talented, or powerful
Risky behaviors such as going on spending sprees or having reckless sex

Causes of mood disorders:

Genetics
Chronic stress
Mental illness
Isolation
Poor coping strategies

3. Psychotic disorders

Psychotic disorders are characterized by distorted awareness and thinking. Schizophrenia is a common example of a psychotic disorder.

Symptoms of psychotic disorders:

Hallucinations
Delusions
Disorganized thoughts or speech
Lack of emotion and/or changes in facial expression
Difficulty understanding speech or other forms of communication
Difficulty making sense of new information
Difficulty solving problems
Anxiety
Depression
Lack of interest in spending time with people or having fun
Minimal movement or talking
Poor hygiene
Problems learning and remembering

Causes of psychotic disorders:

Stress
Drug abuse
Major life changes
Family history
Chemical (glutamate) imbalance in the brain

4. Eating disorders

Eating disorders involve abnormal thoughts or behavior about food and weight and may cause people to eat too much or too little. Eating disorders can lead to heart and kidney problems. Common eating disorders include:

Anorexia nervosa
Bulimia nervosa
Binge eating

Symptoms of eating disorders:

Dramatic weight loss
Exercising excessively
Refusal to eat certain foods
Avoiding mealtimes or eating in front of others
Complaining about constipation or stomach pain
Constant dieting
Complaining about being fat
Wearing baggy clothes to hide the body
Hiding food in strange places

The exact cause of eating disorders is unknown, although a complex interaction of the following factors can lead to their development:

Genetic
Biological
Behavioral
Psychological
Social

5. Personality disorders

People with personality disorders have unhealthy, inflexible thoughts and behaviors that may pose serious problems with relationships and work. Common personality disorders include:

Borderline personality disorder
Narcissistic personality disorder
Antisocial personality disorder

Symptoms of personality disorders:

Social anxiety that causes difficulty making friends
Desiring constant attention
Lack of impulse control or difficulty delaying gratification
Inability to realize or admit their faults (ego-syntonic symptoms)
Blaming others for their behaviors and feelings
Feeling of being cheated or exploited
Mood swings
Angry outbursts

Causes of personality disorder:

Genetics
Childhood trauma

6. Post-traumatic stress disorder (PTSD)

PTSD develops after a traumatic experience such as sexual assault, physical assault, natural disaster, or death of a loved one. Memories of the trauma may have disturbing effects on the person.

Symptoms of post-traumatic stress disorder:

Reliving the trauma including memories, nightmares or flashbacks
Feeling “numb”
Trouble sleeping
Avoiding certain people or places
Intense feelings such as anger, fear or worry

7. Impulse control and addiction disorders

These disorders are characterized by an irresistible urge to engage in risky behaviors or get addicted to certain substances. Common impulse control and addiction disorders include:

Pyromania
Kleptomania
Compulsive gambling
Substance abuse

Symptoms of impulse control and addiction disorders:

Hair pulling
Stealing
Compulsive lying
Poor social skills
Ignoring responsibilities and relationships
Being aggressive toward animals
Destroying the property of others
Starting fires
Violating rules such as running away or skipping school at an early age

Causes of impulse control and addiction disorders:

History of physical or emotional trauma
Problems with emotional regulation
Neglectful or abusive parenting
Exposure to violence

8. Factitious disorders

Factitious disorder is a psychological condition in which a person acts as if they have a physical or mental illness when they do not, making up or exaggerating symptoms. They may even tamper with medical tests to convince others that they need treatment.

The most common falsified symptoms and diseases include:

Abdominal pain
Arthralgia (joint pain)
Chest pain
Diarrhea
Infections
Hypoglycemia (low blood glucose level)
Hematuria (blood in the urine)
Hyperthyroidism
Skin wounds that do not heal
Vomiting
Weakness

Potential warning signs of factitious disorders:

Unclear or inconsistent symptoms
Extensive knowledge about hospitals, medical terms, and illnesses
Frequent hospital stays
Conditions that don’t respond to standard treatment
Conditions that may worsen following an improvement in the condition
Presence of many scars
Refusal of a psychiatric or psychological evaluation
Refusing doctors to meet or talk with family members, friends, and previous doctors
Appearance of new symptoms following negative test results
Eagerness to undergo medical tests, procedures, or operations
Predicting negative medical outcomes despite no evidence
Having few visitors while hospitalized
Arguing with hospital and medical staff
Disrupting discharge plans or exaggerating symptoms while being discharged
Presence of symptoms when alone or when not being observed
Remarkable but inconsistent medical history

Causes of factitious disorders:

History of child abuse or neglect
History of illnesses that requires the individual to visit hospitals
Trauma
Family dysfunction
Social isolation
Early chronic medical illness
Depression
Low self-esteem
Work in the healthcare field
Loss of a loved one through death

9. Obsessive-compulsive disorder (OCD)

OCD is characterized by disturbing thoughts or fears that cause people to perform repetitive rituals or routines. Compulsions are not connected in a realistic way to the feared event.

Symptoms of OCD:

Repetitive and persistent thoughts
Repetitive behaviors such as washing hands or changing clothes too frequently
Feeling overly stressed when there is any change in routine
Excessive fear of germs or dirt
Repeatedly counting or checking things

10. Sexual and gender disorders

Sexual and gender disorders affect sexual desire, performance, and behavior. Common sexual and gender disorders include:

Sexual dysfunction
Gender identity disorder
Paraphilias

Symptoms of sexual and gender disorders:

Conflict between gender assigned at birth and gender identity
Sexual urges relating to objects
Inhibited sexual desire
Avoiding sexual opportunities for fear of failure

Causes of sexual and gender disorders:

Chromosomal abnormalities
Hormonal abnormalities
Exposure to certain hormones before birth
Congenital adrenal hyperplasia