Patients affected by ADT tachyphylaxis experience a noticeably sudden progressive decrease in response to SSRIs. The reported rates of this condition vary from 9% to 33% of SSRI users, and the majority of those affected are less responsive to subsequent treatments. In most observational studies, these individuals suffer a recurrence or relapse of depression without changing the previously effective dose.

ADT tachyphylaxis incorporates drug sensitivity as a potential causal factor for the decreased response. However, tolerance provides a more accurate explanation. While the exact cause of ADT tachyphylaxis in individual cases is unknown, drug tolerance is a more comprehensive model, as it includes mechanisms of pharmacodynamic tolerance, metabolic tolerance, and others.

Antidepressant treatment tachyphylaxis (ADT tachyphylaxis), also known as Prozac poop-out, is a medical condition in which progressive or acute tolerance effects are seen following chronic administration of a drug. ADT tachyphylaxis specifically refers to a sudden decrease in response to selective serotonin reuptake inhibitors (SSRIs), which are the most commonly prescribed antidepressants. Although less commonly prescribed as antidepressants (having lost popularity following the introduction of SSRIs), monoamine oxidase inhibitors, or MAOIs, have also incurred a "poop-out" effect among depressed patients.

The behavioral symptoms are similar to those of an amphetamine, cocaine or caffeine overdose. Overstimulation of the central nervous system results in a state of hyperkinetic movement and unpredictable mental status including mania, rage and suicidal behavior.

Physical symptoms are more serious and include heart arrhythmias as well as outright heart attack or stroke in people who are at risk of coronary disease. Breathing is rapid and shallow while both pulse and blood pressure are dangerously elevated.

A mental breakdown (also known as a nervous breakdown) is an acute, time-limited mental disorder that manifests primarily as severe stress-induced depression, anxiety, or dissociation in a previously functional individual, to the extent that they are no longer able to function on a day-to-day basis until the disorder is resolved. A nervous breakdown is defined by its temporary nature, and often closely tied to psychological burnout, severe overwork, sleep deprivation, and similar stressors, which may combine to temporarily overwhelm an individual with otherwise sound mental functions.

SPS is diagnosed by demonstrating platelet hyperaggregability. In a lab test called aggregometry platelet stickyness is stimulated with epinephrine (EPI) and/or adenosine diphosphate (ADP). This test is not possible for patients being treated with acetylsalicylic acid until that substance has sufficiently cleared from their system.

Bernard–Soulier syndrome often presents as a bleeding disorder with symptoms of:

An adrenergic storm is a sudden and dramatic increase in serum levels of the catecholamines adrenalin and noradrenalin (also known as epinephrine and norepinephrine respectively), with a less significant increase in dopamine transmission. It is a life-threatening condition because of extreme tachycardia and hypertension, and is especially dire for those with prior heart problems. If treatment is prompt, prognosis is good; typically large amounts of diazepam or other benzodiazepines are administered alongside beta blockers. Beta blockers are contraindicated in some patients, so other anti-hypertensive medication such as clonidine may be used. It is usually caused by overdose of stimulants, especially cocaine or methamphetamine, or eating foods high in tyramine while taking monoamine oxidase inhibitors. A subarachnoid hemorrhage can also cause an adrenergic storm. A catecholamine storm is part of the normal course of Rabies infection, and is responsible for the severe feelings of agitation, terror, and dysautonomia present in the pre-coma stage of the disease.

HELLP usually begins during the third trimester; rare cases have been reported as early as 21 weeks gestation. Often, a woman who develops HELLP syndrome has already been followed up for pregnancy-induced hypertension (gestational hypertension), or is suspected to develop pre-eclampsia (high blood pressure and proteinuria). Up to 8% of all cases occur after delivery.

Women with HELLP syndrome often appear non-toxic. Early symptoms can include:

- In 90% of cases, either epigastric pain described as "heartburn" or right upper quadrant pain develops.

- In 90% of cases, malaise occurs.

- In 50% of cases, nausea or vomiting happen.

Gradual but marked onset of headaches (30%), blurred vision, and paresthesia (tingling in the extremities) can occur. Edema may occur, but its absence does not exclude HELLP syndrome. Arterial hypertension is a diagnostic requirement, but may be mild. Rupture of the liver capsule and a resultant hematoma may occur. If a woman has a seizure or coma, the condition has progressed into full-blown eclampsia.

Disseminated intravascular coagulation is also seen in about 20% of all women with HELLP syndrome, and in 84% when HELLP is complicated by acute renal failure. Pulmonary edema is found in 6% of all women with HELLP syndrome, and when HELLP is complicated by acute renal failure, pulmonary edema is found in 44% of women with the syndrome.

A woman with symptoms of HELLP can be misdiagnosed in the early stages, increasing the risk of liver failure and morbidity. Rarely, after a caesarean section surgery, a woman may have signs and symptoms of a shock condition mimicking either pulmonary embolism or reactionary haemorrhage.

Symptoms usually present from the period of birth to early childhood as: nose bleeds, bruising, and/or gum bleeding. Problems later in life may arise from anything that can cause internal bleeding such as: stomach ulcers, surgery, trauma, or menstruation. Abnormality of the abdomen, Epistaxis, Menorrhagia, Purpura, Thrombocytopenia, and prolonged bleeding time have also been listed as symptoms of various Giant Platelet Disorders.

Late life depression refers to a major depressive episode occurring for the first time in an older person (usually over 50 or 60 years of age). Concurrent medical problems and lower functional expectations of elderly patients often obscure the degree of impairment. Typically, elderly patients with depression do not report depressed mood, but instead present with less specific symptoms such as insomnia, anorexia, and fatigue. Elderly persons sometimes dismiss less severe depression as an acceptable response to life stress or a normal part of aging.

Sticky platelet syndrome is a term used by some to describe a disorder of platelet function. It was first described by Mammen in 1983. It is inherited in an autosomal dominant pattern. It has not been associated with a specific gene, and it is not recognized as an entity in OMIM.

Among researchers using the term, it has been described as a coagulation disorder that can present in conjunction with protein S deficiency and Factor V Leiden. It is not currently known if sticky platelet syndrome is a distinct condition, or if it represents part of the presentation of a more well characterized coagulation disorder.

Individuals with QPD are at risk for experiencing a number of bleeding symptoms, including joint bleeds, hematuria, and large bruising. In 2010, the genetic cause of QPD has been determined as a mutation involving an extra copy of the uPA (urokinase plasminogen activator) gene http://bloodjournal.hematologylibrary.org/content/115/6/1264.long. The mutation causes overproduction of an enzyme that accelerates blood clot breakdown.

The terms "nervous breakdown" and "mental breakdown" have not been formally defined through a medical diagnostic system such as the DSM-5 or ICD-10, and are nearly absent from current scientific literature regarding mental illness. Although "nervous breakdown" is not rigorously defined, surveys of laypersons suggest that the term refers to a specific acute time-limited reactive disorder, involving symptoms such as anxiety or depression, usually precipitated by external stressors. Many health experts today refer to a nervous breakdown as a "modern mental health crisis."

Specific cases are sometimes described as a "breakdown" only after the emotional and physical demands on a person's life are so great as to prevent him or her from performing activities of daily living or, less strictly, only when those demands prevent him/her from performing his/her familial or occupational duties.

Nervous breakdowns are often caused by serious ongoing mental health disorders.

Characteristically, there is increased mucosal bleeding:

- menorrhagia

- easy bruising

- epistaxis

- gingival bleeding

- gastrointestinal bleeding

- postpartum bleeding

- increased bleeding post-operatively.

The bleeding tendency is variable but may be severe. Hemarthrosis, particularly spontaneous, is very rare, in contrast to the hemophilias.

Platelet numbers and morphology are normal. Platelet aggregation is normal with ristocetin, but impaired with other agonists such as ADP, thrombin, collagen or epinephrine.

Giant platelet disorders are rare disorders featuring abnormally large platelets, thrombocytopenia and a tendency to bleeding. Giant platelets cannot stick adequately to an injured blood vessel walls, resulting in abnormal bleeding when injured. Giant platelet disorder occurs for inherited diseases like Bernard-Soulier syndrome, gray platelet syndrome and May-Hegglin anomaly.

Type 2 vWD (15-30% of cases) is a qualitative defect and the bleeding tendency can vary between individuals. Four subtypes exist: 2A, 2B, 2M, and 2N. These subtypes depend on the presence and behavior of the underlying multimers.

Nearly every day, others may see that the person's activity level is not normal. People suffering from depression may be overly active (psychomotor agitation) or be very lethargic (psychomotor retardation). If a person is agitated, they may find it difficult to sit still, may pace the room, wring their hands, or fidget with clothes or objects. Someone with psychomotor retardation tends to move sluggishly, may move across a room very slowly, avert their eyes, sit slumped in a chair and speak slowly, saying little. They might say that their arms and legs feel heavy.

To meet diagnostic criteria, changes in motor activity must be so abnormal that it can be observed by others. Personal reports of feeling restless or feeling slow do not count towards the diagnostic criteria.

Type 1 vWD (60-80% of all vWD cases) is a quantitative defect which is heterozygous for the defective gene. It can arise from failure to secrete vWF into the circulation or from vWF being cleared more quickly than normal. Decreased levels of vWF are detected at 20-50% of normal, i.e. 20-50 IU.

Many patients are asymptomatic or may have mild symptoms and not have clearly impaired clotting, which might suggest a bleeding disorder. Often, the discovery of vWD occurs incidentally to other medical procedures requiring a blood work-up. Most cases of type 1 vWD are never diagnosed due to the asymptomatic or mild presentation of type I and most people usually end up leading a normal life free of complications, with many being unaware that they have the disorder.

Trouble may, however, arise in some patients in the form of bleeding following surgery (including dental procedures), noticeable easy bruising, or menorrhagia (heavy menstrual periods). The minority of cases of type 1 may present with severe hemorrhagic symptoms.

Glanzmann's thrombasthenia is an abnormality of the platelets. It is an extremely rare coagulopathy (bleeding disorder due to a blood abnormality), in which the platelets contain defective or low levels of glycoprotein IIb/IIIa (GpIIb/IIIa), which is a receptor for fibrinogen. As a result, no fibrinogen bridging of platelets to other platelets can occur, and the bleeding time is significantly prolonged.

Nearly every day, the person may sleep excessively, known as hypersomnia, or not enough, known as insomnia.

Insomnia is the most common type of sleep disturbance for people who are clinically depressed and is often associated with a melancholic type of depression. Symptoms of insomnia include trouble falling asleep, trouble staying asleep, and/or waking up too early in the morning.

Hypersomnia is a less common type of sleep disturbance. It may include sleeping for prolonged periods at night or increased sleeping during the daytime. The sleep may not be restful, and the person may feel sluggish despite many hours of sleep. This impacts their everyday activities and ability to focus at home or work. According to the United States National Library of Medicine, people with seasonal affective disorder (SAD) may sleep longer during the winter months. Hypersomnia is often associated with an atypical depression. Hypersomnia is not as common as insomnia and up to 40% of people exhibit hypersomnia from time to time.

To meet criteria for a major depressive episode, a patient must have 5 of these 9 symptoms nearly every day for at least 2 weeks.

1. Depressed or sad mood

2. Anhedonia (loss of interest in pleasurable activities)

3. Sleep disturbance (increased or decreased sleep)

4. Appetite disturbance (increased or decreased appetite) typically with weight change

5. Energy disturbance (increased or decreased energy/activity level), usually fatigue

6. Poor memory and/or concentration

7. Feelings of guilt or worthlessness

8. Psychomotor retardation or agitation (a change in mental and physical speed perceived by other people)

9. Thoughts of wishing you were dead; suicidal ideation or suicide attempts

The most important differential diagnosis is disseminated intravascular coagulation, which is characterized with similar features but presence of a low platelet count and microcirculatory thrombosis. Antifibrinolytic treatments are contraindicated in patients with disseminated intravascular coagulation while they are useful in the treatment of primary fibrinogenolysis.

Tardive Dysmentia is a rarely used term introduced in a 1983 paper to describe "changes in affect, activation level, and interpersonal interaction", and hypothesized to be caused by long-term exposure to neuroleptic drugs in the same way as the much better known syndrome of tardive dyskinesia. Several papers in the following years discussed the validity of the concept, and this small literature was reviewed in a 1993 publication by M. S. Myslobodsky, who drew attention to the "possibility that the syndrome of dysmentia is occasional excessive emotional reactivity, enhanced responsiveness to environmental stimuli, and indifference to or reduced awareness of the patient's abnormal involuntary movements", but concluded that the pathophysiology is uncertain. Since then, the term has fallen into disuse, receiving at most only passing mentions in the literature.

Primary fibrinogenolysis is the pathological lysis of fibrinogen characterized with a low fibrinogen, high fibrin degradation products, prolonged prothrombin time and activated partial thromboplastin time, a normal platelet count and absence of microcirculatory thrombosis.

Quebec Platelet Disorder (QPD) is a rare, autosomal dominant bleeding disorder described in a family from the province of Quebec in Canada.