Dementia is a general term for a decline in mental ability severe enough to interfere with daily life. Memory loss is an example. Alzheimer’s is the most common type of dementia.

Alzheimer’s disease is one of the most common cognitive disorders, affecting approximately 5.4 million Americans. It typically begins with minor signs of forgetfulness such as difficulty remembering well-known names or recent events.  Initial symptoms are often indistinguishable from normal memory errors. However, as the disease progresses, the affected person’s memory becomes persistently impaired.

Delirium is a serious disturbance in mental abilities that results in confused thinking and reduced awareness of your environment. The start of delirium is usually rapid — within hours or a few days. Delirium can often be traced to one or more contributing factors, such as a severe or chronic medical illness, changes in your metabolic balance (such as low sodium), medication, infection, surgery, or alcohol or drug withdrawal.

Amnesia refers to the loss of memories, such as facts, information and experiences. People with amnesia are usually lucid and know who they are, but may have trouble learning new information and forming new memories. It can be caused by damage to areas of the brain that are vital for memory processing. Amnesia can be permanent.

Attention Deficit Hyperactivity Disorder (ADHD) is usually diagnosed during childhood and often persists into adulthood.  It is the most commonly diagnosed behavioral disorder in children and can cause significant problems with home, school, and social interaction.

Symptoms of ADHD include inattention, wandering off task, having difficulty maintaining focus, being disorganized, hyperactivity, excessive running about, fidgeting, tapping, or talking, and impulsivity.

Asperger’s syndrome is a condition on the autism spectrum, with generally higher functioning.  This developmental disorder affects a person’s ability to effectively socialize and communicate.  People with this condition may be socially awkward and have an all-absorbing interest in specific topics.

Depression is when feelings of loss, anger, sadness, or frustration make it hard for you to do the things you enjoy in everyday life. Although everyone feels sad sometimes, depression lasts longer and interferes with your daily life. With major depression, a person must be depressed for at least 2 weeks, but often for as long as 20 weeks.

People with Bipolar Disorder have moods that swing from depression to mania. Also called manic-depressive disorder.

Seasonal affective disorder (SAD) is a kind of depression that is seasonal and happens when there is less sunlight. It starts during fall-winter and disappears during spring-summer.

Narcissistic personality disorder is a mental disorder in which people have an inflated sense of their own importance, a deep need for admiration and a lack of empathy for others. This can cause problems in many areas of life, such as relationships, work, school or financial affairs.

Paranoid Personality Disorder is a condition in which a person has a long-term pattern of distrust and suspicion of others, but does not have a full-blown psychotic disorder such as schizophrenia.

Obsessive-Compulsive Disorder (OCD) is a common, chronic and long-lasting disorder in which a person has uncontrollable, reoccurring thoughts (obsessions) and behaviors (compulsions) that he or she feels the urge to repeat over and over.

Schizophrenia is a severe, lifelong brain disorder.  People who have it may hear voices, see things that aren’t there or believe that others are reading or controlling their minds.  Symptoms might include hallucinations, or seeing things, and delusions such as hearing voices, unusual thoughts or perceptions, disorders of movement, difficulty speaking and expressing emotion, and problems with attention, memory and organization.

Delusional disorder is a disorder where a person has trouble recognizing reality.  A delusion is a false belief that is based on an incorrect interpretation of reality.  A person with this illness holds a false belief firmly, despite clear evidence or proof to the contrary.  Delusions may involve circumstances that could occur in reality even though they are unlikely (for example, the family next door plotting to kill you).  Or they may be considered “bizarre” (for example, feeling controlled by an outside force or having thoughts inserted into your head).

Gender Identity Disorder is defined by strong, persistent feelings of identification with the opposite gender and discomfort with one’s own assigned sex that results in significant distress or impairment.  For instance, a person identified as a boy may feel and act like a girl.

Most cases of insomnia are related to poor sleep habits, depression, anxiety, lack of exercise, chronic illness, or certain medications.  Symptoms may include difficulty falling or staying asleep and not feeling well-rested.

Insomnia can sap not only your energy level and mood but also your health, work performance and quality of life.

Alcohol Abuse is a pattern of drinking that interferes with day-to-day activities.  With alcohol abuse, a person is not yet physically dependent on alcohol, but still has a serious drinking problem.

Symptoms include a failure to fulfill major work, school, or home responsibilities, legal or social problems, or drinking in situations that are dangerous, such as while driving.

Chemical dependency is a primary disease in which a person becomes addicted to drugs or alcohol.  People with chemical dependency continue to use drugs or alcohol, even knowing that continued use causes damages to their bodies, families, finances, and all other aspects of life.

Signs and symptoms of chemical dependency are loss of interest in formerly enjoyable activities and preoccupation with the drug (including spending excessive amounts of time figuring out where to get the next dose and daydreaming about using the drug).