After more than three decades in psychiatric practice, patterns begin to emerge that no textbook can adequately teach. One of the most consistent—and most frequently overlooked—patterns I have encountered involves patients labeled as having “treatment-resistant depression.” Again and again, beneath the surface of persistent low mood, hopelessness, and emotional exhaustion, I have found an illness that was never properly named: obsessive-compulsive disorder.

Many of these patients arrive having tried multiple antidepressants, augmentation strategies, and years of psychotherapy. They are discouraged, often demoralized, and convinced that something is fundamentally broken within them. What is striking is not a lack of insight or effort, but the presence of relentless mental activity—intrusive thoughts that invade consciousness and compulsive behaviors designed to neutralize the resulting anxiety. Over time, this unrecognized obsessive-compulsive cycle produces a secondary depression that is profound, enduring, and resistant to conventional treatments aimed at mood alone.

These individuals suffer from intrusive thoughts that are repetitive, unwanted, and deeply distressing. They are not fleeting worries but persistent mental assaults, often centered on harm, morality, contamination, or responsibility. In response, patients engage in compulsive behaviors—both overt and covert—in an effort to regain a sense of safety or certainty. These may include checking, reassurance seeking, mental review, avoidance, confession, or rumination. The relief is temporary, and the cycle inevitably resumes, leaving the patient exhausted and despairing.

Over the years, I have come to recognize that what clinicians often interpret as helplessness or passivity is, in fact, the result of relentless internal labor. These patients are not inactive; they are overactive in the most punishing way possible—locked into endless loops of obsession and compulsion that offer no durable resolution. Eventually, the emotional toll of this process gives rise to depression that appears primary but is actually secondary to untreated obsessive-compulsive pathology.

A particularly common and painful manifestation of this pattern is religious scrupulosity. In these cases, obsessive-compulsive disorder masquerades as moral or spiritual failure. Patients are consumed by fears of sin, impurity, blasphemy, or having violated their deepest values. Guilt and shame dominate their inner world. They may believe they are failing God, betraying their faith, or morally deficient at a core level.

What makes scrupulosity especially difficult to recognize is that both patients and clinicians may accept the moral narrative at face value. The psychiatric distress becomes obscured by theological language. Yet, after decades of listening carefully, the underlying structure is unmistakable: intrusive thoughts that are ego-dystonic and unwanted, followed by compulsive behaviors—often prayer, confession, or reassurance seeking—intended to relieve anxiety rather than deepen faith. The brain remains in a state of obsessive hyperarousal, demanding absolute certainty and moral perfection, neither of which is attainable.

In such cases, guilt is not evidence of moral failure; it is a symptom. The patient’s suffering is not spiritual deficiency but neuropsychiatric dysregulation. When this distinction is missed, well-intentioned interventions may inadvertently reinforce the disorder, deepening the patient’s sense of shame and prolonging the illness.

With experience comes a sobering realization: treatment resistance is often diagnostic resistance. When obsessive-compulsive disorder is not identified—particularly in its less obvious, cognitively driven forms—patients are treated for depression that cannot resolve because its true engine remains active. Only when the obsessive-compulsive cycle is addressed directly does the depressive fog begin to lift.

After thirty years of practice, I have learned to listen not only for sadness, but for repetition; not only for despair, but for mental rigidity; not only for guilt, but for anxiety disguised as conscience. Recognizing obsessive-compulsive disorder beneath the surface of depression is not merely a refinement of diagnosis—it is often the turning point in a patient’s long and painful journey