Other Mental Disorders

As we have learned in this course, in the United States, the DSM serves as the principal authority for psychiatric diagnoses. Treatment recommendations, as well as payment by health care providers, are often determined by DSM classifications. The categories of other mental disorders are as follows:

• neurodevelopmental disorders
• schizophrenia spectrum and other psychotic disorders
• bipolar and related disorders
• depressive disorders
• anxiety disorders
• obsessive-compulsive and related disorders
• trauma and stressor-related disorders
• dissociative disorders
• somatic symptom and related disorders
• feeding and eating disorders
• elimination disorders
• sleep-wake disorders
• sexual dysfunctions
• gender dysphoria
• disruptive, impulse control,  and conduct-related disorders
• substance-related and addictive disorders
• neurocognitive disorders
• personality disorders
• paraphilic disorders

There are a few lesser-known areas of the DSM-5 that aid in classifying disorders related to other medical conditions or medications. Some disorders coincide with other medical conditions that cause distress or impairment of a mental disorder, but that do not meet the full criteria for another mental disorder; these include other specified mental disorder due to another medical condition or unspecified mental disorder due to another medical condition. Other mental disorders may also be labeled other specified mental disorder if there is significant distress or impairment in functioning, but the full criteria are not met for a mental disorder or unspecified mental disorder if there is likely a mental disorder present but insufficient information for the diagnosis.

Medication-Induced Movement Disorders

The DSM-5 also contains a section on medication-induced movement disorders and other adverse effects of medication that are not mental disorders, but complications or problems connected to the medication used to manage mental disorders.

Movement disorders are clinical syndromes with either an excess of movement or a paucity of voluntary and involuntary movements, unrelated to weakness or spasticity. Movement disorders are synonymous with basal ganglia or extrapyramidal diseases. Movement disorders are conventionally divided into two major categories—hyperkinetic and hypokinetic. Hyperkinetic movement disorders refer to dyskinesia, or excessive, often repetitive, involuntary movements that intrude upon the normal flow of motor activity. Hypokinetic movement disorders refer to akinesia (lack of movement), hypokinesia (reduced amplitude of movements), bradykinesia (slow movement), and rigidity. In primary movement disorders, abnormal movement is the primary manifestation of the disorder. In secondary movement disorders, abnormal movement is a manifestation of another systemic or neurological disorder.

Types of disorders mentioned in the DSM-5 include the following:

• neuroleptic-induced parkinsonism: Parkinson’s-like tremors, rigidity, or changes in movement following a change in medication
• neuroleptic malignant syndrome: hyperthermia (high body temperature) caused by antipsychotic medications, specifically a dopamine antagonist
  

  Figure 1. An artist’s rendition of akathisia. They describe suffering from akathisia as having burning pain and involuntary movements.

• medication-induced acute dystonia: abnormal muscles contractions following a change in medication
• medication-induced acute akathisia: restlessness and fidgeting following a change in medication
• tardive dyskinesia: involuntary, repetitive body movements, which may include grimacing, sticking out the tongue, or smacking the lips
• tardive dystonia: permanent sustained or repetitive muscle contractions result in twisting and repetitive movements or abnormal fixed postures
• tardive akathisia: involves painful feelings of inner tension and anxiety and a compulsive drive to move the body
• medication-induced postural tremor and other medication-induced movement disorder: involuntary muscle contractions or twitching
• antidepressant discontinuation syndrome: flu-like symptoms, trouble sleeping, nausea, poor balance, sensory changes, and anxiety

Tardive Dyskinesia

Tardive dyskinesia is a disorder that results in involuntary, repetitive body movements, which may include grimacing, sticking out the tongue, or smacking the lips. Additionally, symptoms may be rapid jerking movements or slow writhing movements. In about 20% of people with tardive dyskinesia, the disorder interferes with daily functioning.

Tardive dyskinesia occurs in some people as a result of long-term use of dopamine-receptor blocking medications such as antipsychotics and metoclopramide. These specific medications are usually used for mental illness, but may also be given for gastrointestinal or neurological problems. The condition typically develops only after months to years of use. A diagnosis is based on the symptoms after ruling out other potential causes.

Antidepressants are sometimes associated with movement disorders. Among antidepressants, mirtazapine, vortioxetine, amoxapine, phenelzine, tryptophan, and fluvoxamine were associated with the highest level of movement disorders and citalopram, paroxetine, duloxetine, and mirtazapine were the most frequently associated with movement disorders. A potential harmful association was found between movement disorders and the use of the antidepressants mirtazapine, vortioxetine, amoxapine, phenelzine, tryptophan, fluvoxamine, citalopram, paroxetine, duloxetine, bupropion, clomipramine, escitalopram, fluoxetine, mianserin, sertraline, venlafaxine, and vilazodone.

Efforts to prevent the condition include either using the lowest possible dose or discontinuing the use of neuroleptics. Treatment includes stopping the neuroleptic medication if possible or switching to clozapine. Other medications such as valbenzaline, tetrabenazine, or botulinum toxin may be used to lessen the symptoms. With treatment, some see a resolution of symptoms while others do not. Rates in those on atypical antipsychotics are about 20%, while those on typical antipsychotics have rates of about 30%. The risk of acquiring the condition is greater in older people. The term tardive dyskinesia first came into use in 1964.

Tardive dyskinesia is characterized by repetitive, involuntary movements. Some examples of these types of involuntary movements include

• grimacing.
  

  Figure 2. Involuntary puckering or pursing of the lips can be associated with tardive dyskinesia.

• tongue movements.
• lip-smacking.
• lip puckering.
• pursing of the lips.
• excessive eye blinking.
• rapid, involuntary movements of the limbs, torso, and fingers.

Prevention of tardive dyskinesia is achieved by using the lowest effective dose of a neuroleptic for the shortest time. However, with diseases of chronic psychosis such as schizophrenia, this strategy must be balanced with the fact that increased dosages of neuroleptics are more beneficial in preventing the recurrence of psychosis. If tardive dyskinesia is diagnosed, the causative drug should be discontinued.

Antidepressant Associated Movement Disorder

A study on antidepressants using the WHO Pharmacovigilance database was assessed among adverse drug reactions related to any antidepressant, from January 1967 to February 2017, through a case/non-case design. The association between nine subtypes of movement disorders (akathisia, bruxism, dystonia, myoclonus, parkinsonism, restless legs syndrome, tardive dyskinesia, tics, and tremor) and antidepressants was estimated through the calculation first of crude Reporting Odds Ratio (ROR), then adjusted ROR on four potential confounding factors: age, sex, drugs described as able to induce movement disorders, and drugs used to treat movement disorders.

Antidepressants are one of the most frequently prescribed drug classes in Western countries. They have broad therapeutic indications, from depression to anxiety or obsessive-compulsive disorders, but also enuresis, chronic pain, or eating disorders. The most important classes of antidepressants are selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), and monoamine oxidase inhibitors (MAOIs). Antidepressants act mainly through the monoamine neurotransmitters, serotonin, and noradrenaline. They can induce several adverse drug reactions, including not only digestive disorders, sexual dysfunction, fatigue, or sleepiness, but also hyponatremia, hepatitis, or bleeding.

Movement disorders are clinical syndromes with either an excess or a paucity of voluntary and involuntary movements, unrelated to weakness or spasticity. They include extrapyramidal symptoms (akathisia, tardive dyskinesia, dystonia, and parkinsonism) but also a wide range of disorders, from tremor to tics and bruxism, to name a few. Although not the most frequent adverse drug reactions of antidepressants, antidepressant-induced movement disorders have been described and can lead to severe and disabling conditions. Reports of extrapyramidal symptoms associated with antidepressants have been documented for SSRIs, SNRIs, and other antidepressants.

When comparing each of the classes of antidepressants with the others, a significant association was observed for all subtypes of movement disorders except restless legs syndrome with SSRIs only. Among antidepressants, mirtazapine, vortioxetine, amoxapine, phenelzine, tryptophan, and fluvoxamine were associated with the highest level of movement disorders and citalopram, paroxetine, duloxetine, and mirtazapine were the most frequently associated with movement disorders. A potential harmful association was found between movement disorders and the use of the antidepressants mirtazapine, vortioxetine, amoxapine, phenelzine, tryptophan, fluvoxamine, citalopram, paroxetine, duloxetine, bupropion, clomipramine, escitalopram, fluoxetine, mianserin, sertraline, venlafaxine, and vilazodone.