Skip to Content

What is the hardest psychological disorder to treat?

Psychological disorders encompass a wide range of conditions that affect mood, thinking, and behavior. They can vary greatly in severity, from manageable issues to completely debilitating illnesses. When it comes to treatment, some psychological disorders respond better than others. Factors like the complexity of symptoms, social stigma, patient engagement, and access to proper care can all impact how difficult it is to successfully treat a given condition. So which psychological disorder stands out as the most challenging to treat effectively? There are several top contenders based on treatment resistance, relapse rates, and the chronic nature of the illness.


Depression is one of the most common psychological disorders, affecting over 300 million people globally. The primary symptoms are persistent feelings of sadness, hopelessness, and loss of interest in normal activities. While many people with depression do improve with treatment, full remission can be difficult to achieve.

Up to two-thirds of depression patients respond to initial treatment, but relapse rates are very high. Around 50% of people will relapse after their first depressive episode. After two or three episodes, the relapse rate can be as high as 90%. Even after multiple treatment attempts, approximately 20% of those with depression have a chronic course that is unresponsive to intervention.

Treatment resistance occurs for many reasons. The chronic stress, lack of social support, and biological vulnerability that contribute to depression are often ongoing issues that are not easily corrected. Finding an effective medication can also be a challenge since patients respond differently. Additionally, residual symptoms tend to linger even when mood improves. Motivation and engagement in treatment can suffer when energy is low and apathy is high.

Bipolar Disorder

Bipolar disorder causes extreme shifts in mood and energy, fluctuating between manic and depressive states. These episodes can be frequent or rare, mild or severe. Around 2.8% of U.S. adults have bipolar disorder.

While mood stabilizers and antipsychotics are effective, the long-term prognosis for bipolar disorder is fairly poor. At least 60% of those with bipolar remain symptomatic despite treatment. Relapse is very common — even those who achieve remission have a 60-70% chance of recurrence within two years.

The recurring manic and depressive episodes make bipolar disorder a challenge to manage. Treatment is often complicated by the side effects of medication, lack of insight during manic phases, disruptions to sleep patterns, substance abuse, and the high risk of suicide associated with depressive periods.

Personality Disorders

Personality disorders are rigid, unhealthy patterns of thinking and behaving that impair relationships and functioning. They emerge in adolescence or early adulthood and remain stable throughout life.

Three of the most concerning personality disorders are borderline personality disorder (BPD), narcissistic personality disorder (NPD), and antisocial personality disorder (ASPD). These cluster B disorders share tendencies like impulsivity, unstable emotions, and difficulty empathizing. They are estimated to affect up to 15% of the general population.

Cluster B disorders are notoriously resistant to treatment. Their pervasive nature makes them difficult to manage. Trust, confrontation avoidance, ego defense, and lack of motivation pose obstacles.

Up to 35% of those with BPD remain symptomatic even after several years of therapy. Relapse is high, around 60% for BPD and nearly 100% for NPD and ASPD. Medications have little impact since these disorders stem from ingrained personality.

Borderline Personality Disorder

BPD causes turbulent emotions, impulsive behavior, and unstable personal relationships. Self-harm and suicidal behavior are common — around 80% of people with BPD attempt suicide at some point.

DBT (dialectical behavior therapy) is the frontline treatment for BPD. It teaches coping skills and helps patients rein in harmful impulses. However, high dropout rates are an issue. Given the volatility of BPD, progress is often a rollercoaster.

Narcissistic Personality Disorder

NPD manifests as an exaggerated sense of self-importance, need for admiration, and lack of empathy. Arrogance, exploitation of others, and an excessive need for control are also common.

Treatment compliance for NPD is notoriously low. Those affected rarely pursue help voluntarily. They are usually forced into treatment by family members, legal mandates, or when relationships crumble. When in therapy, narcissists often reject or undermine the process.

Antisocial Personality Disorder

Antisocial personality disorder entails a pervasive disregard for others. Deceitfulness, hostility, impulsivity, and lack of remorse are characteristic. Criminal behavior, aggression, and substance abuse are common.

Standard psychotherapy is generally ineffective for ASPD. These individuals do not take responsibility for their actions and are skilled at manipulating others, including therapists. Forced treatment, such as court-ordered programs for offenders, has marginal impact at best.


Schizophrenia is a severe mental illness marked by profound disruptions to thinking, emotion, and behavior. Delusions, hallucinations, disordered communication, limited emotional expression, and impaired functioning are common symptoms.

While many people with schizophrenia improve significantly with treatment, recovery is variable. Around 20% to 30% have ongoing severe psychotic symptoms. Relapse after initial improvement is unfortunately very common — over 80% will experience recurrent acute episodes.

Treatment resistance is an issue in 30% to 60% of schizophrenia patients. Poor medication adherence, lack of social support, substance abuse, and untreated psychosis worsen long-term outcomes. The advanced brain changes that occur in schizophrenia also make full remission a major challenge.

Anorexia Nervosa

Anorexia nervosa is a life-threatening eating disorder characterized by self-starvation and excessive weight loss. It has the highest mortality rate of any psychiatric disorder. Anorexia affects up to 1% of U.S. women.

Effective treatment for anorexia is complicated by poor motivation and denial of illness. Weight restoration and normal eating are primary goals. But restrictive eating behaviors and urges are extremely challenging for patients to overcome. Relapse is common — around a third remain unwell despite intensive treatment.

Additionally, years of malnourishment and mental preoccupation with food changes brain function in ways that stubbornly persist after weight gain. Given the egosyntonic nature of anorexic thoughts, sufferers struggle to redefine their relationship with food and their own body.

Obsessive Compulsive Disorder

Obsessive compulsive disorder (OCD) causes intrusive, irrational thoughts and repetitive behaviors. Unwanted thoughts generate intense anxiety that compel sufferers to perform compulsive rituals as a way of coping. Around 2% of U.S. adults live with OCD.

While 80% of those with OCD improve with treatment, full remission is uncommon. Nearly 60% continue to experience symptoms that impair their quality of life. Even with therapeutic gains, residual compulsions, anxiety, and obsessions often linger.

Treatment challenges include perfectionism tendencies, family accommodation of rituals, and behavioral avoidance. Exposure therapy is effective but extremely difficult for patients. The shame and secrecy surrounding OCD symptoms also hinders progress.


When considering the most treatment-resistant psychological disorders, severe mental illnesses like schizophrenia and bipolar disorder come to mind. Personality disorders like borderline, narcissistic, and antisocial PD also have very poor long-term prognoses.

However, looking at recovery and relapse rates, anorexia nervosa and OCD stand out as especially challenging. The egosyntonic thought patterns central to these disorders result in low motivation and high rates of residual symptoms even after therapy. The chronic, relapsing nature of most psychological illnesses underscores the need for better long-term treatments.