Question: What disorder did the song " You're Only Human" refer too? 

Context paragraphs:
You're Only Human (Second Wind): "You're Only Human (Second Wind)" is a song written in 1985 and performed by Billy Joel.  The song deals with teenage depression and suicide.  It originally appeared on "Billy Joel's Greatest Hits" in 1985 and became a top ten hit, peaking at #9 on the "Billboard" Hot 100.

Psychosexual disorder: Psychosexual disorder is a term which may simply refer to a sexual problem that is psychological, rather than physiological in origin.  "Psychosexual disorder" was a term used in .  The term of psychosexual disorder (Turkish: "Psikoseksüel bozukluk") used by the TAF for homosexuality as a reason to ban the LGBT people from military service.

Substance use disorder: Substance use disorder (SUD), also known as drug use disorder, is a condition in which the use of one or more substances leads to a clinically significant impairment or distress.  Although the term "substance" can refer to any physical matter, 'substance' in this context is limited to psychoactive drugs. Addiction and dependence are components of a substance use disorder and addiction represents the most severe form of the disorder.

Childhood disintegrative disorder: The childhood disintegrative disorder (CDD), also known as Heller's syndrome and disintegrative psychosis, is a rare condition characterized by late onset of developmental delays—or stunning reversals—in language, social function, and motor skills.  Researchers have not been successful in finding a cause for the disorder.  CDD has some similarity to autism, and is sometimes considered a low-functioning form of it.  In May 2013, the term CDD, along with other types of autism, was fused into a single diagnostic term called "autism spectrum disorder" under the new DSM-5 manual.  Therefore, CDD is now also called "regressive autism", being that this term can now refer to any type of autism spectrum disorder that involves regression, including CDD.

Major depressive disorder: Major depressive disorder (MDD), also known simply as depression, is a mental disorder characterized by at least two weeks of low mood that is present across most situations.  It is often accompanied by low self-esteem, loss of interest in normally enjoyable activities, low energy, and pain without a clear cause.  People may also occasionally have false beliefs or see or hear things that others cannot.  Some people have periods of depression separated by years in which they are normal while others nearly always have symptoms present.  Major depressive disorder can negatively affect a person's personal, work, or school life, as well as sleeping, eating habits, and general health.  Between 2–7% of adults with major depression die by suicide, and up to 60% of people who die by suicide had depression or another mood disorder.

Sexual dysfunction: Sexual dysfunction (or sexual malfunction or sexual disorder) is difficulty experienced by an individual or a couple during any stage of a normal sexual activity, including physical pleasure, desire, preference, arousal or orgasm.  According to the DSM-5, sexual dysfunction requires a person to feel extreme distress and interpersonal strain for a minimum of 6 months (excluding substance or medication-induced sexual dysfunction).  Sexual dysfunctions can have a profound impact on an individual's perceived quality of sexual life.  The term "sexual disorder" may not only refer to physical sexual dysfunction, but to paraphilias as well; this is sometimes termed "disorder of sexual preference".

Larsen syndrome: Larsen syndrome (LS) is a congenital disorder discovered in 1950 by Larsen and associates when they observed dislocation of the large joints and face anomalies in six of their patients.  Patients suffering from Larsen syndrome normally present with a variety of symptoms, including congenital anterior dislocation of the knees, dislocation of the hips and elbows, flattened facial appearance, prominent foreheads, and depressed nasal bridges.  Larsen syndrome can also cause a variety of cardiovascular and orthopedic abnormalities.  This rare disorder is caused by a genetic defect in the gene encoding filamin B, a cytoplasmic protein that is important in regulating the structure and activity of the cytoskeleton.  The gene that influences the emergence of Larsen syndrome is found in chromosome region, 3p21.1-14.1, a region containing human type VII collagen gene.  Larsen syndrome has recently been described as a mesenchyme disorder that affects the connective tissue of an individual.  Autosomal dominant and recessive forms of the disorder have been reported, although most cases are autosomal dominant.  Reports have found that in Western societies, Larsen syndrome can be found in one in every 100,000 births, but this is most likely an underestimate because the disorder is frequently unrecognized or misdiagnosed.

Female sexual arousal disorder: Female sexual arousal disorder (FSAD) is a disorder characterized by a persistent or recurrent inability to attain sexual arousal or to maintain arousal until the completion of a sexual activity.  The diagnosis can also refer to an inadequate lubrication-swelling response normally present during arousal and sexual activity.  The condition should be distinguished from a general loss of interest in sexual activity and from other sexual dysfunctions, such as the orgasmic disorder (anorgasmia) and hypoactive sexual desire disorder, which is characterized as a lack or absence of sexual fantasies and desire for sexual activity for some period of time.

Porencephaly: Porencephaly is an extremely rare cephalic disorder involving encephalomalacia.  It is a neurological disorder of the central nervous system characterized by cysts or cavities within the cerebral hemisphere.  Porencephaly was termed by Heschl in 1859 to describe a cavity in the human brain.  Derived from Greek roots, the word "porencephaly" means 'holes in the brain'.  The cysts and cavities (cystic brain lesions) are more likely to be the result of destructive (encephaloclastic) cause but can also be from abnormal development (malformative), direct damage, inflammation, or hemorrhage.  The cysts and cavities cause a wide range of physiological, physical, and neurological symptoms.  Depending on the patient, this disorder may cause only minor neurological problems, without any disruption on intelligence, while others may be severely disabled or face death before the second decade of their lives.  However, this disorder is far more common within infants, and porencephaly can occur in both before or after birth.

Nature deficit disorder: Nature deficit disorder is a phrase coined by Richard Louv in his 2005 book "Last Child in the Woods" meaning that human beings, especially children, are spending less time outdoors resulting in a wide range of behavioral problems.  This disorder is not recognized in any of the medical manuals for mental disorders, such as the ICD-10 or the DSM-5.  Evidence was compiled and reviewed in 2009.  Richard Louv has stated "nature-deficit disorder is not meant to be a medical diagnosis but rather to serve as a description of the human costs of alienation from the natural world".

Supporting paragraphs: You're Only Human (Second Wind) Major depressive disorder
Answer: Major depressive disorder