Comorbidity

See also: Prevalence

"Dissociative identity disorder frequently co-occurs with other psychiatric diagnoses, such as anxiety disorders (especially post-traumatic stress disorder-PTSD), mood disorders, somatoform disorders, eating disorders, as well as sleep problems and sexual dysfunction.^[3] Dissociative identity disorder has been found to more commonly occur with particular personality disorders including Avoidant Personality Disorder (76% co-morbidity), Self-defeating Personality Disorder (68% co-morbidity), Borderline Personality Disorder (53% co-morbidity) and Passive-Aggressive Personality Disorder (45% co-morbidity).^[68] Schizotypal Personality Disorder also had a 58% crossover with dissociative tendencies."^[68]

Diagnoses commonly comorbid with dissociative disorders

Across studies and clinical summaries, dissociative disorders (esp. DID/OSDD and severe dissociation) tend to cluster with:

• Trauma-related disorders

  • PTSD (including the dissociative subtype featuring depersonalization/derealization). (PTSD VA)

• Depressive disorders

  • Major depression is extremely common in DID clinical samples; depression–dissociation co-occurrence is a consistent finding. (ScienceDirect)

• Anxiety disorders

  • Often present alongside PTSD and depression in dissociative presentations. (PMC)

• Substance use disorders

  • Frequently comorbid in trauma/dissociation populations; comorbid SUD is associated with greater severity/impairment in some reviews. (Delaware Academy of Medicine)

• Somatic symptom / conversion / Functional Neurological Disorder (FND) presentations

  • Dissociative disorders and conversion/functional symptoms show notable overlap in some samples and are commonly discussed together in the trauma-dissociation literature (including PNES/“functional dissociative seizures”). (PMC)

• Personality disorders—especially BPD

  • Dissociation is common in BPD, and BPD frequently co-occurs with PTSD (a common “bridge” diagnosis in complex trauma presentations). (PMC)

A practical clinical takeaway: high dissociation usually means “don’t stop at one diagnosis.” You often need to assess PTSD, depression/anxiety, substance use, and functional/somatic symptom patterns in parallel, because any one of these can dominate the presenting complaint and mask the dissociative picture.

Prevalence: how common are dissociative disorders?

Prevalence estimates vary a lot depending on:

• population (community vs. outpatient vs. inpatient),

• assessment method (screeners vs. structured diagnostic interviews like SCID-D/DDIS),

• and what counts (DID vs. broader dissociative disorders including OSDD/DDNOS and dissociative amnesia).

Community samples

• A widely cited community study in Turkey found 18.3% lifetime prevalence of any dissociative disorder, with DDNOS 8.3% and DID 1.1%. (ScienceDirect)

• A major epidemiology review (Şar, 2011) summarizes community work and reports figures like ~1–2% for depersonalization/derealization disorder, and notes that broader dissociative disorders can be substantially higher depending on definitions/interviews. (Arne Blindheim)

• Clinical summaries often cite DID around ~1–1.5% in the general population (again, method-dependent). (NCBI)

Psychiatric outpatient settings

• In one well-known outpatient study (Foote et al., 2006), structured interviews found 29% met criteria for a dissociative disorder, and 6% met criteria for DID. (Psychiatry Online)

Psychiatric inpatient settings

• Reviews note pathological dissociation and dissociative disorders are higher in inpatient groups than in the general population, though exact rates differ by study and instruments. (PMC)

•  Dissociative disorders are not “rare” in clinical populations when you actually interview for them. Outpatient studies using structured interviews find surprisingly high rates. (Psychiatry Online)

• Comorbidity is the rule, not the exception—especially with PTSD, depression/anxiety, substance use, and functional/somatic symptom presentations. (PTSD VA)