The five main types of anxiety disorders are Generalized Anxiety Disorder, Obsessive-Compulsive Disorder (OCD), Panic Disorder, Post-Traumatic Stress Disorder (PTSD), and Social Phobia (or Social Anxiety Disorder).
Autism Spectrum Disorders (ASD), also known as Pervasive Developmental Disorders (PDDs), cause severe and extensive impairment in thinking, feeling, language, and the ability to relate to others. These disorders are usually first diagnosed in early childhood and range from a severe form, called autistic disorder, through pervasive development disorder not otherwise specified (PDD-NOS), to a much milder form, Asperger syndrome.
Depression is a serious medical illness — it's not something made up. It's more than just feeling "down in the dumps" or "blue" for a few days. It's feeling "down" and "low" and "hopeless" for weeks at a time.
Schizophrenia is a chronic, severe, and disabling brain disorder that affects about 1 percent of people all over the world. People with schizophrenia sometimes hear voices others don't hear, believe that others are broadcasting their thoughts to the world, or become convinced that others are plotting to harm them.
Researchers believe that both depression and suicidal behavior can be linked to decreased serotonin in the brain. Low levels of a serotonin metabolite, 5-HIAA, have been detected in cerebral spinal fluid in persons who have attempted suicide, as well as by postmortem studies examining certain brain regions of suicide victims.
Although the majority of people who have depression do not die by suicide, having major depression does increase suicide risk compared to people without depression. The risk of death by suicide may, in part, be related to the severity of the depression.
Suicide contagion is the exposure to suicide or suicidal behaviors within one's family, one's peer group, or through media reports of suicide and can result in an increase in suicide and suicidal behaviors. Direct and indirect exposure to suicidal behavior has been shown to precede an increase in suicidal behavior in persons at risk for suicide, especially in adolescents and young adults.
There is growing evidence that familial and genetic factors contribute to the risk for suicidal behavior. Major psychiatric illnesses, including bipolar disorder, major depression, schizophrenia, alcoholism and substance abuse, and certain personality disorders, which run in families, increase the risk for suicidal behavior.
Alcohol and substance abuse problems contribute to suicidal behavior in several ways. Persons who are dependent on substances often have a number of other risk factors for suicide. In addition to being depressed, they are also likely to have social and financial problems.