What is lycanthropy?
Lycanthropy, derived from the Greek words lykos (wolf) and anthropos (human), is a rare psychiatric syndrome in which a person believes they can transform into a wolf or other animal. This delusional disorder, also known as clinical...
What is logorrhea?
Logorrhea, also known as "pressured speech," is a condition marked by excessive and frequently incoherent talkativeness. The term is derived from Greek, with "logo" meaning "word" and "rrhea" meaning "flow." People with logorrhea typically have rapid, unrelenting...
What is lithium toxicity?
Lithium toxicity, also called lithium overdose or lithium poisoning, is a potentially fatal condition caused by high levels of lithium in the bloodstream. Lithium is commonly prescribed as a mood stabilizer for people suffering from bipolar...
Lewy Body Dementia (LBD) is a progressive neurological disorder characterized by abnormal accumulation of the protein alpha-synuclein in the brain. These clumps, known as Lewy bodies, disrupt normal brain function, primarily affecting areas responsible for cognitive functions, motor control,...
Latah is a rare culturally bound syndrome characterized by an exaggerated startle reflex followed by automatic, involuntary behaviors such as mimicry (echolalia or echopraxia), compulsive command compliance (automatic obedience), and inappropriate verbal or physical responses. Latah was first discovered...
What is anosognosia?
Anosognosia, also known as "lack of insight," is a neurological condition in which a person fails to recognize or acknowledge their own illness or impairment. Anosognosia, as opposed to denial, which is a psychological defense mechanism, is...
What is the Labile Mood?
Labile mood, also known as emotional lability or mood instability, refers to sudden and unpredictable changes in emotional states. Individuals with labile mood can quickly shift from happiness to sadness, anger, or irritability without any...
What is Korsakoff syndrome?
Korsakoff Syndrome, also known as Korsakoff's psychosis, is a chronic neuropsychiatric disorder caused by a severe lack of thiamine (vitamin B1), a nutrient required for brain function. Korsakoff Syndrome, which is commonly thought to be a...
What is Kluver-Bucy syndrome?
Kluver-Bucy Syndrome (KBS) is a rare and complex neurological disorder caused by damage to the anterior temporal lobes, specifically the amygdala and hippocampus, which regulate emotion, memory, and behavior. Heinrich Klüver and Paul Bucy first described...
What is kleptomania?
Kleptomania is a rare and complex impulse control disorder characterized by a recurring desire to steal items that are rarely needed for personal or monetary gain. Unlike typical theft, kleptomania involves compulsive, uncontrollable urges to steal that...
Kleine-Levin Syndrome (KLS), also known as "Sleeping Beauty Syndrome," is a rare and complex neurological disorder marked by recurring episodes of excessive sleepiness (hypersomnia), altered behavior, and cognitive impairments. During these episodes, people may sleep for up to 20...
What is juvenile myoclonic epilepsy (JME)?
Juvenile Myoclonic Epilepsy (JME) is a common type of genetic generalized epilepsy that usually starts in adolescence, between the ages of 12 and 18. JME is characterized by myoclonic jerks, which are sudden, brief,...
What is Joubert syndrome?
Joubert Syndrome (JS) is a rare genetic disorder that affects the development of the cerebellum, a brain region responsible for balance, coordination, and movement. This condition, first described in 1969, is distinguished by a unique brain...
What is Irritable Bowel Syndrome?
Irritable Bowel Syndrome (IBS) is a common functional gastrointestinal disorder that causes chronic abdominal discomfort, pain, bloating, and changes in bowel habits such as diarrhea, constipation, or a combination of the two. It is a...
What are intrusive thoughts?
Intrusive thoughts are involuntary, distressing, and unwanted mental images or ideas that interfere with normal cognitive functions. These thoughts can range from mildly uncomfortable to extremely distressing, depending on the content and the individual's sensitivity to...
What are Intoxication-Related Disorders?
Intoxication-related disorders are mental health conditions caused by the consumption or abuse of substances like alcohol, drugs, and other psychoactive substances. These disorders develop when a substance directly affects the brain, causing a variety of mental...
What is Intermittent Explosive Disorder?
Intermittent Explosive Disorder (IED) is a mental health condition characterized by sudden, intense bouts of anger or aggression that are out of proportion to the circumstances. Individuals with IED frequently experience impulsive outbursts—such as verbal...
What is Intellectual Disability (Intellectual Development Disorder)?
Intellectual Disability (ID), also known as Intellectual Developmental Disorder (IDD), is a neurodevelopmental disorder characterized by significant limitations in both intellectual functioning and adaptive behavior that impair a person's ability to learn, reason,...
What is Insomnia Disorder?
Insomnia disorder is a common sleep disorder marked by persistent difficulty falling asleep, staying asleep, or waking up too early and unable to fall back asleep. In contrast to occasional sleeplessness, insomnia becomes a chronic problem...
What is Impulse Control Disorder?
Impulse-Control Disorders (ICDs) are a group of psychiatric conditions defined by an inability to resist urges or impulses that can be harmful to oneself or others. These disorders are characterized by repetitive and compulsive behaviors...
What is Illness Anxiety Disorder?
Illness Anxiety Disorder (IAD), formerly known as hypochondriasis, is a mental health condition marked by an intense preoccupation with the belief that one has or will develop a serious illness, despite the lack of medical...
What is hypomania?
Hypomania is a mental health condition marked by elevated mood, increased energy, and hyperactivity, but on a less severe scale than full-blown mania. It is commonly associated with bipolar II disorder, a condition in which people alternate...
What is hypochondriasis?
Hypochondriasis, also known as Illness Anxiety Disorder (IAD) in the DSM-5, is a psychological condition defined by an excessive preoccupation with having a serious illness despite the lack of medical evidence to support such concerns. Individuals with...
What is hypersomnia?
Hypersomnia is a sleep disorder that is distinguished by excessive daytime sleepiness, prolonged nighttime sleep, or difficulty staying awake during the day despite adequate or extended nighttime rest. Individuals with hypersomnia experience overwhelming drowsiness throughout the day,...
What is Hypersexuality Disorder?
Hypersexual Disorder, also known as compulsive sexual behavior disorder, is a condition defined by an intense preoccupation with sexual thoughts, urges, or behaviors that causes significant distress or impairment in daily functioning. This disorder is commonly...
What is hyperactivity disorder?
Hyperactivity Disorder, also known as Attention-Deficit/Hyperactivity Disorder (ADHD), is a neurodevelopmental condition marked by persistent patterns of inattention, hyperactivity, and impulsivity that disrupt daily functioning or development. ADHD typically manifests in childhood, but symptoms can last...
What is Huntington's disease?
Huntington's Disease (HD) is a rare, inherited neurodegenerative disorder that gradually impairs cognitive and physical function. It is caused by a genetic mutation in the HTT gene, which produces abnormal huntingtin protein, gradually damaging neurons in...
Hoarding Disorder is a psychological condition characterized by persistent difficulty discarding or letting go of possessions, regardless of their actual value. Individuals with this disorder experience intense emotional distress at the prospect of disposing of items, resulting in the...
What is histrionic personality disorder (HPD)?
Histrionic Personality Disorder (HPD) is a psychiatric condition characterized by a persistent pattern of overemotionality and attention-seeking behavior. Individuals with HPD frequently feel uncomfortable when they are not the center of attention and may...
What is Hallucinogenic Persisting Perception Disorder (HPPD)?
Hallucinogen Persisting Perception Disorder (HPPD) is a rare and distressing condition that develops after using hallucinogenic substances like LSD, psilocybin mushrooms, or MDMA. Individuals with HPPD experience persistent visual disturbances, such as visual...
