864 articles
Severe X-linked intellectual disability, Gustavson type
Severe X-linked intellectual disability, Gustavson type (Gustavson syndrome, MRXSG, OMIM 309555) is a rare X-linked recessive disorder caused by RBMX variants, marked by profound intellectual disability, microcephaly, optic atrophy, deafness, seizures, spasticity, and early childhood death.
Sex and gender differences in autism
Sex and gender differences in autism: males are diagnosed about 3–4 times more often than females (CDC 2022 ratio 3.4), a gap moderated by intellectual disability, camouflaging, and underdiagnosis, with proposed genetic, hormonal, and neurodevelopmental mechanisms.
Sex therapy
Sex therapy: a psychotherapy subspecialty treating sexual concerns like desire, arousal, and pain. Founded on Masters and Johnson's 1966–1970 behavioral work; AASECT offers voluntary certification requiring 90 hours sexuality training, 60 hours therapy training, and 50 supervision hours.
Sexual addiction
Sexual addiction, also called hypersexual disorder or out-of-control sexual behavior, is a proposed pattern of uncontrolled sexual behavior; not in DSM-5, its ICD-11 counterpart is compulsive sexual behavior disorder (CSBD), an impulse control disorder.
Sexual arousal disorder
Sexual arousal disorder, or female sexual arousal disorder (FSAD), is a sexual dysfunction of reduced genital and subjective arousal despite desire and stimulation; DSM-5 now classifies it as female sexual interest/arousal disorder (FSIAD), distinct from persistent genital arousal disorder.
Sexual fantasy
Sexual fantasy, also called erotic fantasy or sexual daydream, is imagined sexual content that arouses. Research shows few fantasies are rare; 68.8% report BDSM fantasies; only 1.7% of men with paraphilic fantasies feel distress.
Shirley Ardell Mason
Shirley Ardell Mason, aka Sybil, 1923-1998, Minnesota-born artist and psychiatric patient of Cornelia Wilbur, subject of the 1973 book Sybil; her 16-personality case was later shown to be largely fabricated.
Sigmund Freud
Sigmund Freud (1856–1939), Austrian neurologist and founder of psychoanalysis; born in Freiberg, Moravia, worked in Vienna, fled the Nazis in 1938, died in London; wrote The Interpretation of Dreams and Studies on Hysteria.
Silent treatment
Silent treatment: deliberate withholding of communication to punish, control, or avoid conflict; a dyadic form of ostracism studied by Kipling Williams, linked to pain, stonewalling, and relationship dissolution.
Single episode depressive disorder
Single episode depressive disorder is an ICD-11 diagnosis (code 6A70) for a person who has had exactly one depressive episode, with no prior episodes and no history of mania.
Sleep-related bruxism
Sleep-related bruxism (sleep bruxism) is rhythmic or non-rhythmic masticatory muscle activity during sleep, now classed as a behavior rather than a disorder; diagnosed by PSG-AV or portable EMG (cut-off 7 events/hour), managed with splints and biofeedback.
Sleep-related eating disorder
Sleep-related eating disorder (SRED), ICD-11 7B00.3, is a parasomnia of involuntary eating during the main sleep period with amnesia, unlike night eating syndrome; linked to sleepwalking, RLS, OSA, and sedative-hypnotics, treated with topiramate or treating the underlying sleep disorder.
Smith-Magenis syndrome
Smith-Magenis syndrome (SMS, 17p11.2 deletion syndrome) is a rare neurodevelopmental disorder caused by a 17p11.2 deletion (~90%) or RAI1 variant (~10%), with intellectual disability, inverted melatonin secretion, sleep disturbance, and self-injurious behavior.
Smoking cessation
Smoking cessation: quitting tobacco smoking via behavioral counseling, quitlines, and medications (NRT, bupropion, varenicline, cytisine, e-cigarettes). Combined treatment roughly doubles quit rates; WHO issued a 2024 clinical guideline.
Social anxiety
Social anxiety (social phobia, social anxiety disorder) is persistent fear of scrutiny in social situations, affecting 7.1% of U.S. adults yearly; first-line treatment is individual CBT, with SSRIs/SNRIs as medication options.
Social anxiety disorder
Social anxiety disorder, previously known as social phobia, is a common anxiety condition involving lasting fear of scrutiny, judgment, or embarrassment in social and performance situations.
Social media and suicide
Social media and suicide covers contagion risks (Werther effect, nearly threefold risk from exposure to suicidality in one's network) and protective uses (Papageno effect, AI-based risk detection, crisis support) across platforms like Instagram, Reddit, and Facebook.
Social withdrawal
Social withdrawal is retreat from relationships and social interactions, an ICD-11 symptom code (MB23.Q) and DSM-5 Detachment facet, ranging from shyness to hikikomori, and linked to schizophrenia, depression, and anxiety.
Somatic delusion
Somatic delusion (ICD-11 MB26.09; delusional disorder, somatic type in DSM-5): a fixed false belief of disease, defect, or infestation of the body, seen in delusional disorder, schizophrenia, mood psychosis, and substance- or medical-induced psychosis.
Somatic experiencing
Somatic Experiencing (SE), developed by Peter A. Levine, is a body-oriented trauma therapy using interoception, titration, and pendulation; first RCT (Brom 2017) showed large PTSD symptom reductions, but overall evidence remains preliminary.
Somatic hallucinations
Somatic hallucinations (ICD-11 MB27.25) are false perceptions of internal bodily sensations, such as organs moving, without external stimuli; bodily or proximity-sense hallucinations, less common than auditory ones (4-19% in psychosis) and usually multimodal.
Somatic symptom disorder
Somatic symptom disorder (SSD), a DSM-5 diagnosis introduced in 2013, replaces DSM-IV somatoform disorders and hypochondriasis; distinguished from illness anxiety disorder by the presence of distressing somatic symptoms with excessive thoughts, feelings, and behaviors lasting six months or more.
Somatization
Somatization: expressing emotional distress as physical symptoms, historically tied to hysteria and Briquet's syndrome; now DSM-5 somatic symptom disorder and ICD-11 bodily distress disorder, treated mainly with CBT.
Special interest (autism)
A special interest, also known as a restricted or circumscribed interest, is an intense, highly focused interest found in an estimated 75 to 95 percent of autistic people.
Speedball (drug)
Speedball: simultaneous stimulant-opioid use, classically heroin plus cocaine injected together; variants include goofball (heroin-methamphetamine) and super speedball (cocaine with fentanyl); higher overdose risk than either drug alone.
Stage fright
Stage fright: performance-context anxiety driven by sympathetic-adrenal activation (adrenaline, noradrenaline, cortisol). Affects 16.5-60% of professional musicians; treated with CBT, exposure, and beta-blockers; distinct from glossophobia and generalized social anxiety.
Status quo bias
Status quo bias, coined by Samuelson and Zeckhauser (1988), is the non-rational preference for keeping the current state or default option, explained by loss aversion, transition costs, and sunk costs, and documented in health plans, retirement saving, and organ donation.
Stereotyped movement disorder
Stereotyped movement disorder (SMD, motor stereotypies, ICD-11 6A06) is a neurodevelopmental disorder of repetitive, purposeless movements such as hand flapping or head banging, beginning before age 3, treated mainly with habit reversal training.
Stereotypy
Stereotypy: repetitive, rhythmic, apparently purposeless movements, object use, or vocalizations (hand flapping, rocking, echolalia) with early-childhood onset; seen in autism, intellectual disability, and healthy children; basal ganglia-based, usually automatically reinforced.
Steve Pieczenik
Steve Pieczenik, former U.S. Deputy Assistant Secretary of State and hostage negotiator, later co-creator of Tom Clancy's Op-Center and Net Force novels, and an Infowars guest known for Sandy Hook and bin Laden conspiracy claims.